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Casting
- How do I avoid air bubbles in my part?
- How do you use Alumidust and Metallic powders?
- What is the best way to pour my part to eliminate air bubbles that are formed when casting?
- Can you vary ratios?
- How much heat does Alumilite generate?
- Can the set time be increased?
- What is the difference between Alumilite Regular and Alumilite White?
- Can Alumilite be colored? What do I use?
- Are all of Alumilite's resins UV Stable?
- How long should I mix Alumilite?
- Why are Ultra-lite 400, Shell, and Replicator series resins so thick or look to be separating?
- How much heat can Alumilite take before deforming or melting?
- Can I paint Alumilite?
- Can I spin cast Alumilite?
- Can I rotational mold Alumilite?
- What kind of mold release can I use?
- Why is my Alumilite Casting resin foaming?
- Is it necessary to vacuum or pressure the Water Clear and Flex 80?
- Is there difference between the Alumilite Clear and the Water Clear?
- My Alumilite is leeching an oily residue, is it old?
- My part is very hard to get out of my one piece silicone mold. Is there anything I can do to help it release easier?
- How do I determine if I need a mold release?
- If I short pour a mold, can I add more? Does Alumilite bond to itself well?
- What glues work best for gluing something to Alumilite?
- How do I polish clear resins?
- Why is my clear resin white or cloudy?
- Can I thin the resin to make it flow easier into fine recesses? What is your thinnest resin?
- It has been 4 hours and my clear resin is still flexible, will it harden?
- My Flex Urethane is gelling is it still useable?
- Can the Flexible Series be dyed?
- How long does it take Performance 80D to fully cure such that the data sheet specifications can be expected. I see that demold time is 1 to 2 hours, but how long until full strength is obtained?
- I have a application that I need to seal wires with connectors in a 1/2 inch slab. Is the Alumilite conductive and if so how much?
- Why am I finding color change in my new Alumilite resin I purchased?
- Is the Amazing Clear Cast UV stable?
- How can I make a semi translucent color with the clear resins?
- How do I tint Alumilite clear casting resins Amber?
- I'm using Alumilite Clear in an open box, and I've run into 2 problems: The resin climbs the sides of the box (capillary action), and the surface of the resin is not flat. Any tips on how to get a completely flat surface on the back?
- Can Alumilite be used as an insulator?
- I have some dried crystals in my Casting Resin in the bottom of the bottle is it useable?
- Is there a casting resin that replicate model car tires?
- Are any Alumilite casting resins food safe?
- Can food coloring be used to color Alumilite casting resins?
- What Alumilite resin is best for machining?
- What causes Performance 65 or 80D castings to be soft and/or sticky?
- What are the proper mix ratios for Alumilite Clear Casting Resins? Do they differ?
- Are Alumilite Casting Resins waterproof?
Molding
- What is the difference between the High Strength 2 and the High Strength 3 moldmaking rubber?
- What types of molds can I pour Alumilite into?
- What is catalyst?
- Why is the surface of my silicone mold tacky?
- What rubbers are compatible to pour over one another?
- How many parts will I get per mold before the mold starts to break down?
- Is there anything I can do to prolong the life of the mold?
- What is vacuuming and why should I do it?
- How large of a mold can I make from silicone?
- What kind of detail can I expect from RTV silicones?
- Are all your silicones FDA approved?
- What is the shelf life for liquid silicone as well the the mold making putty?
- How long will a silicone mold last?
- Is there something I can do to make my RTV silicone thinner and softer?
- I need a silicone that I can paint on to a vertical surface to capture a relief, is there such a thing?
- How do I clean a mold when I am through with it?
- Can I do anything to minimize/eliminate bubbles when making my mold without using vacuum equipment?
- How much by volume do I get in my 1 pound and 10 pound kit of Silicone, High Strength specifically?
- Can the quickset silicone be used as a brush on in the making of an antler mold" from Products
Misc
- Is Alumilite safe or toxic?
- What is the shelf life for Alumilite's casting resins?
- What is the shelf life of silicone moldmaking rubbers?
- Can I buy just one side of Alumilite or just catalyst for the rubber?
- Do you ship your products internationally?
- What is durometer and viscosity, along with other terminology that will help me understand, what I am looking for, what I need and what I am getting?
- What factors contribute to shrinkage in molding & casting parts?
- My paint is not adhering, is it from my mold release?
- Can I remove silicone and/or Alumilite from a work surface?
- What do I do if I am still having problems with moldmaking or casting projects and can't find answers in FAQ'S?
- What is the best/safest way to dispose of unused/expired casting material?
- What if I want to expand the volume of my resin?
- Are Alumilite liquid dyes suppose to be this thick?
- Can you paint resin that contains porcelain powder?
- How much volume can I expect out of 5 lbs of Microballoons?

Casting
How do I avoid air bubbles in my part?
Cast Alumilite into a warm mold coated with baby powder. This will help the material flow better and cure more evenly. If you are using silicone rubber, stick the mold in an oven set at “Warm” for approximately 30 minutes or put your mold in a microwave on high for 1 minute per lb of rubber. Once your mold is warm to the touch, sprinkle baby powder or talc powder in the mold. Shake the powder around the mold so all areas are covered. Once covered, knock or blow out all of the excess powder. This will leave a light coat of powder on the outside of the mold that will release the surface tension and allow the material to flow much better reducing the chance of trapping air bubbles. You can also use any kind of paint or commercial brand of urethane release to aid in the problem if baby powder isn’t available. For complex molds that have severe undercuts, you may need to vent those troubled areas with holes that can be created with either some copper tubing or an Excel or Exacto knife.

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How do you use Alumidust and Metallic powders?
There are three ways to use Alumidust. (1) Brush it on you your silicone mold. It will bond to the Alumisol or any Alumilite casting resins. (2) Mix it into your casting resin or Alumisol. (3) Brush it on the surface of cooled soft plastic lures. You must then quickly pass a heat gun or torch over the surface to briefly remelt the surface of the Alumisol to lock in the Alumidust. Alumidust and Alumilite Metallic Powders are applied the same way. You can also mix colors to create custom colors.

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What is the best way to pour my part to eliminate air bubbles that are formed when casting?
If you are casting a part in an open or one piece mold, pour slowly from one corner of the mold and let the material flow naturally to fill the mold. If it is possible run the material down one side of the mold. If the mold has an undercut or complex corner you may pour the material to that point and then rotate your mold to evenly coat that area before topping off the mold. If you are pouring a closed or two piece mold, fill it completely until the material comes out of the vent hole and then tap the mold on the table to release any bubbles that may need a little assistance to get through the vent hole. You may also wish to rotate the mold and possibly squeeze the sides of the mold to assist hesitant bubbles in reaching the vent.

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Can you vary ratios?
No. Varying the ratios will not affect the working time but it will affect the cure time and physical properties. Meaning, Alumilite will still start to set up in it's normal time but could take hours to completely cure. When it finally does cure, it will not have the same properties of the regular resin and may be considerably weaker.

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How much heat does Alumilite generate?
This depends on the mass you are pouring, but typically ranges between 120°F to 200°F.

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Can the set time be increased?
Yes! To get an additional 30 - 60 seconds, cool the "B" side of Alumilite in the refrigerator for 3-5 hours. When you cool the resin it is important to remember to pour into a warm mold for proper curing.

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What is the difference between Alumilite Regular and Alumilite White?
Alumilite Regular is higher in strength than Alumilite White. Alumilite White is the thinnest resin Alumilite manufactures and is the easiest to use. It is also slightly softer and was created to pick up the absolute best cosmetic reproductions. Both are highly machinable and can be painted, drilled, tapped and sanded.

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Can Alumilite be colored? What do I use?
Yes. Alumilite offers a full line of dyes specially formulated for Alumilite’s Casting Plastics. If you use an outside source make sure that the dyes/pigments are not water based. Some oil-based dyes are compatible. Test a small amount before mixing in larger quantities. Most powdered dyes will work if they do not contain any moisture (known as a dry filler). We also have a line of metallic powders that you may use in your molds to color Alumilite.

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Are all of Alumilite's resins UV Stable?
No. The only naturally UV stable resin is Alumilite’s Water Clear. Alumilite opaque resins will yellow over time if it is exposed to UV light. Clear acrylics or lacquers work well for protecting the resins from changing color. There are two ways of applying paint to achieve the best adhesion. First paint the mold and allow it to completely dry before casting your resin. As the resin flows into the painted mold, it will chemically bond to the paint as the resin is curing and after the resin cures you will demold a perfectly painted part. Painting the mold prior to casting allows you to reproduce perfect detail by painting becoming the outside layer of the actual part rather than cover the exact cast replica with paint that could then cover up fine detail. The other option for painting your part is to paint the part as soon as you remove the cast part from the mold and after you remove any flash while the resin is still curing. Although the resin is demoldable, the casting resin is still curing and if painted during the first 5 or 10 minutes of casting the part, the resin will still crosslink with the paint to give you not only a mechanical bond but also a chemical bond between the paint and the cast piece. Paints have built in UV stabilizers which then block out the UV light from ever reaching the casting resin which could affect the color.

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How long should I mix Alumilite?
Mix thoroughly for 20-30 seconds (be sure to scrape the sides and the bottom of your container). It should be mixed until absolutely no swirls or striations are visible. Try not to mix the resin in the graduated measuring cups because the raised letters and rigid inside prohibits you from scraping the sides effectively.

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Why are Ultra-lite 400, Shell, and Replicator series resins so thick or look to be separating?
These casting resins are heavily filled systems. Fillers can often float to the top, while the resin stays in the bottom of the container or separate in some similar fashion. It's important to mix each side thoroughly, re-suspending all fillers before measuring and mixing side A and B together.

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How much heat can Alumilite take before deforming or melting?
Alumilite will not melt. It will start softening in the mid 200°F and discoloring above 450°F. The shape and design have a lot to do with the physical resistance to heat. If there is no load on the part itself, it may soften at elevated temperatures but with no deform. However if excessive pressure or a load is applied, the resin may start to deform at lower temperatures.

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Can I paint Alumilite?
Yes! We recommend lacquers or acrylics but you may also use synthetics or enamels. A lacquer primer may be needed to assure the long tem effectiveness of the paint. You may wish to paint your silicone mold before casting Alumilite. Paint the mold with a fast drying acrylic or clear coat. Once it is completely dry, cast your piece. When you demold the part you will pull out a painted piece. Alumilite will chemically bond to the dried paint. The other option is to paint the part as soon as it comes out of the mold while the resin is still curing to allow the curing resin to crosslink with the paint.

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Can I spin cast Alumilite?
Yes! Alumilite works extremely well in a spin casting machine. Although spin casting was originated for low melt metals, you can get excellent castings with Alumilite. This technique allows you to produce many parts in a fraction of the time of conventional pouring and provides users a very effective means of casting perfect parts.

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Can I rotational mold Alumilite?
Yes! Alumilite’s low viscosity is ideal for picking up the detail required in thin walled rotational molded pieces. The hollow center will cut cost dramatically by reducing the amount of material that is required to cast your part. (Call us for detail on Rotational Molding Equipment.) Sometimes it is helpful to use microballoons to fill the resin to increase the consistency/viscosity to allow for thicker coats to be rotated at one time.

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What kind of mold release can I use?
If casting into a silicone rubber mold, it is usually not necessary to use a mold release because of it's natural no-stick tendencies. If in doubt, Alumilite offers a Stoner Urethane Mold Release that will not only help release your part but will also extend the life of your mold. If you are pouring into molds that are not made of silicone, a thick layer paste wax or Stoner is required. If you use a mold release, you may need to wash your parts prior to painting in order for the paint to stick. Alumilite's UMR mold release is a dry film release used for separating silicone to silicone, urethane to urethane or urethanes from silicone. It is not as effective as a mold life extender as the Stoner but can be used between multiple materials as where the Stoner is used primarily for releasing urethanes from a mold.

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Why is my Alumilite Casting resin foaming?
Moisture contamination in urethanes causes foaming. If it foams quite a bit, most likely the moisture is right in the Alumilite. The moisture is usually in the A-side. There is not a full proof method of removing moisture from your system. Typically the B side will crystallize when moisture is present. The A side, however, will not look any different. You can try to use a molecular sieve in the A side. Mix the sieve into the resin and allow to settle to the bottom for a couple days. Then test the resin to see if the sieve was effective in removing the air. You can also try to vacuum the A-side to relieve it of moisture. Vacuum the A side for 20-30 minutes until it completely stops bubbling. If you don’t have access to vacuuming equipment or a molecular sieve, the last chance would be to boil the moisture off. This is possible because water has a lower boiling temperature than any of the other liquids in the A-side. To boil off the material, we recommend that you put the Alumilite resin in a glass or metal container and place the material in an oven at 250°F for 2 hours. This will draw the moisture out of the system and evaporate it. If you are getting a bunch of little pinholes, the moisture is probably coming from some materials you are using (mold, cups, stir sticks, filler, etc.).

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Is it necessary to vacuum or pressure the Water Clear and Flex 80?
Not in order for it to cure but yes in order for it to cure with absolutely no air bubbles present within the cast piece as well as the best physical properties. Both of these materials start out at a higher viscosity (thicker) than the other Alumilite resins. Therefore, when these two materials are mixed, the viscosity (consistency) of the material does not allow the air bubbles to freely find their way to the top of the cast piece as the other much thinner resins do before the material cures. These two materials feature a slightly longer open/work time in order for you to either vacuum and/or pressure cast to eliminate all of the bubbles within the casting.

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Is there difference between the Alumilite Clear and the Water Clear?
The Clears are both optically clear and cure to rigid clear castings. However, the Alumilite Clear was developed specifically for more consumer related applications where a higher durometer and better polishability is required. Therefore, the biggest difference between the two is that the Alumilite Clear is slightly harder and polishes much better than the Water Clear, and the Water Clear tends to cure a little better when pouring extremely thin pieces.

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My Alumilite is leeching an oily residue, is it old?
That is usually not the reason for an oily residue. It is however a number of things. If using the Alumilite Regular (found in most starter and refill kits), it may have not been shaken well as the B side seperates after setting and must be shaken prior to use. Another possibility is that it is not measured to the appropriate mix ratio. Alumilite resins are all a 1:1 mixture. Some are by both volume or weight however the Clear, Flex, and Filled systems are only 1:1 by weight. DO NOT alter ratios in hopes of changing pot life or hardness. This does not work. The last and most often issue is the material was not thoroughly mixed. This is most prevelant when most of the piece is hard but there are noticeable swirls and soft areas on the surface of the part. The A must be blended well with B components for a complete chemical crosslink to take place for a full and uniform cure, leaving nothing to leech. Scraping the sides and bottom are crucial steps in mixing the resin thoroughly and avoiding soft spots or unmixed areas that remain wet.

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My part is very hard to get out of my one piece silicone mold. Is there anything I can do to help it release easier?
Yes! To aid in the release of silicone rubber from your mold box or your original, use a small amount of rubbing alcohol. The rubbing alcohol will make the cured silicone very slippery and will help seperate the silicone from the other surface. After you remove the original, dry out the excess alcohol with a paper towel or dry cloth. Be sure to warm and dry out the mold COMPLETELY before pouring resin into the mold to avoid the alcohol from contaminating and affecting the resin. You can also use rubbing alcohol to assist you in removing resin pieces out of a silicone rubber mold. Use the same process as mentioned above for removing your mold from the original and the mold box. Make sure the resin is cured before putting the alcohol in the mold.

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How do I determine if I need a mold release?
The rule of thumb is this; silicone bonds to nothing but another silicone, Alumilite (urethane) bonds to everything but silicone! When pouring RTV silicone against any non silicone surface (exception: a porous surface, such as wood, it would need to be sealed, silicone can wick into the pours while curing), mold release is not required. If you are pouring RTV silicone against itself a rubber to rubber mold release is REQUIRED! If you are pouring Alumilite into anything but silicone, a mold release is REQUIRED. The Stoner Urethane Mold Release works very well for non silicone based molds.

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If I short pour a mold, can I add more? Does Alumilite bond to itself well?
Bonding Alumilite to itself is best when the material is still curing or while it it is still warm. If the Alumilite has cooled down, make sure you have a clean surface and lightly score or/sand in order to give it some bite for better adhesion.

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What glues work best for gluing something to Alumilite?
Bonding something to Alumilite works best when the material is still curing or shortly after demolding. The best adhesives for bonding Alumilite are ones that promote a chemical bond. Adhesives that work include but are not limited to: MMAS, epoxies, CAS (super glues), one part silicones, one part urethanes, and hot melts.

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How do I polish clear resins?
First and foremost, the clear castings should be post cured well with heat. Otherwise the resin may be to soft to get satisfactory results.

Unless there is parting lines or a matte finish, you do not have to wet sand. If sanding is required, start with as coarse as 320 grit (ALWAYS wet sanding) to speed up the finishing process, and gradually work up to 2000 grit for the best results. Progression should go something like this 320-600-800-1200-2000 again, remember, ALWAYS wet sanding.

It is reccomended you polish by hand, but it can be performed using a power buffing set-up if it goes REALLY SLOW! To successfully polish you must not go no more than 300 RPMS at the wheel. Use a loose cotton buff and plenty of 3M Automotive Rubbing Compound. It's messy... but it works like a charm!

Remember to wear you use safety glasses and use a good respirator or do it outside because it is a mess!!!

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Why is my clear resin white or cloudy?
This white swirl or cloudiness happens when the mix ratio becomes heavy with A side. Keep the mix ratio as close to 1:1 by weight as possible. It needs to be measured out by weight, not volume.

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Can I thin the resin to make it flow easier into fine recesses? What is your thinnest resin?
Technical term for thickness/thinness of fluids is viscosity. Viscosity is the measurement of the fluid's internal resistance to flow, this is normally designated in units of centipoise (cps). Put simply, the less viscous the fluid is, the greater its ease of movement (fluidity). There is not a chemical available for purchase to make Alumilite Resin a thinner viscosity. We do have thinner viscosity resins than the Regular Alumilite at 190 cps. Our RC3 (110 cps) and Alumilite White (90 cps, our thinnest resin) are thinner than the Regular Alumilite. The smaller the cps number the thinner the fluid, example water is a 1 cps, #30 motor oil is 250 cps, while honey is 10,000 cps.

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It has been 4 hours and my clear resin is still flexible, will it harden?
A post heat cure is strongly recommended for all clear pieces, but less than 1/8" must be post cured. Post curing the clear on the lowest setting on the conventional oven typically 140-160 F. for an hour or two (parts may require some support during heat curing) will minimize part distortion and shrinkage, while giving maximum toughness. It is also highly recommended to preheat molds to 125F. prior to pouring your resin in the mold.

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My Flex Urethane is gelling is it still useable?
The A side and the B side of the Flex are both very sensitive to moisture. Please store in cool dry area... however when it is time to use again it may have gelled the B side because of the cooler storage temperature. Yes it is still useable. You just need to heat the B side to no more than 150F, using a hot plate or even a very warm pan of water (making sure no moisture droplets are splashed into the resin) until it returns to it's liquid state again. Then shake the B side well, allow it to cool and follow the original mixing instructions.

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Can the Flexible Series be dyed?
Yes they can using the same dyes as you use for the rigid resins. The dye will go in the A side of the Flex, stirred and suspened in the A side before combining the A and B. It is best to dye the Flexible series on an as needed/used basis. Something in the raw materials and the dyes will start to break down the Flex after they are mixed for an extended period of time and it will not perform as it does in it's natural state. If you want to dye the resin for uniform coloring of pieces it is best to use it with in 5-7 days after dying. Make sure the A side is shaken very well one hour prior to mixing, as the dyes and raw materials may start to seperate over time. Always preheat your mold with the Flex series allowing a proper cure and the material to achieve full physical properties.

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How long does it take Performance 80D to fully cure such that the data sheet specifications can be expected. I see that demold time is 1 to 2 hours, but how long until full strength is obtained?
Full cure on almost all of our materials is 72 hours even though over 90% of your physical properties will usually be obtained within 6-8 hours. This is very much part dependent though. Size, thickness, and overall part dimensions can play a role in the curing especially if it is a small or thin piece.

Heating the mold will help the resin cure more evenly and help achieve full cure and full physical properties much quicker than pouring into a cold mold where it is possible the resin never achieves optimum properties.

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I have a application that I need to seal wires with connectors in a 1/2 inch slab. Is the Alumilite conductive and if so how much?
Yes, Alumilite resins will have some insulative properties but not as much as our silicones (QuickSet works well for potting). Silicones will give you much more thermal insulation than urethanes however Alumilite resins will still act as a mild insulator. So much that the components will overheat ... I've never received information from any of our customers that this has caused them problems when potting pcbs with either our urethane resins or the QuickSet which is the typical silicone of choice for potting applications.

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Why am I finding color change in my new Alumilite resin I purchased?
Raw materials we receive in rarely vary in color but it is possible that we received some that was a slightly different shade. Nothing has changed in our formulations and therefore thinking its possible that there might have been a slightly different colored raw that made the resin have a slight hue change. Our RC3 and regular Alumilite are conisdered a "tanish" color, however the RC3 had more of a "buttery" color.

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Is the Amazing Clear Cast UV stable?
It is uv resistant but not uv stable like Alumilite Clear and Water Clear. The big advantage of it lies in the viscosity and cure time which allows you to coat large items such as bar tops as well as gives the air time to release out of the material before curing which in some cases can eliminate the need for degassing some parts that would otherwise require it.

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How can I make a semi translucent color with the clear resins?
The easiest thing to add is Alumilite White dye that contains some titanium dioxide which is opaque. You can also add any color you wish to add to make a semi translucent color. The other option would be to use an actual dry filler like microballoons.

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How do I tint Alumilite clear casting resins Amber?
One user gave us this formula to produce an amber lens: add 1 drop Alumilite Liquid Orange Dye and 5 drops Alumilite Liquid Yellow dye to 2 fl.oz. of mixed resin. Make sure you measure your resin (by weight or by volume) per the instructions for the product you are using.

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I'm using Alumilite Clear in an open box, and I've run into 2 problems: The resin climbs the sides of the box (capillary action), and the surface of the resin is not flat. Any tips on how to get a completely flat surface on the back?
What I like to do is get a piece of glass or thick clear plastic, mold release it!! I like the Stoner release for this application, as I think the UMR hazes the surface a little more than the Stoner. Only use a little to reduce witness marks for the release but make sure you have enough to release it.

You would then over pour the cavity, and use the glass to slowly squish the excess material (from one side to the other) to create perfectly flat back. You do not want to squish the glass past flat. We only want to lay it on the back side until it is flat. If you force the plate too far down, when the mold retracts it will suck in air. So lay the glass on from one side to the other in a slow smooth motion and place an adequate amount of weight on top to hold it in place until it cures.

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Can Alumilite be used as an insulator?
Alumilite resins will have some insulative properties but not as much as our silicones (QuickSet works well for potting). Silicones will give you much more thermal insulation than urethanes however Alumilite resins will still act as a mild insulator. It has never been brought to our attention, from out customers that components will overheat or has caused anyone problems when potting pcbs with either our urethane resins or the QuickSet which is the typical silicone of choice for potting applications.

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I have some dried crystals in my Casting Resin in the bottom of the bottle is it useable?
Mild agitation by rotation of the unopended bottle will dislodged it but it returns after only a few minutes of standing. The best way to get rid of it permanently is to strain the chunks out. You can also simply not pour them into the measuring cup and it will work fine. Sediment in the Iso side (B side) is simply moisture that has reacted with it and fallen to the bottom.

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Is there a casting resin that replicate model car tires?
To replicate tires, use High Strength 2 for the silicone mold making material to make the mold of your original ... 2 piece mold. Flex 80 casting resin with Black dye to reproduce the tire itself. Other products that would help: Corrugated plastic strips to make a mold box Synthetic Clay to clay your two piece mold up UMR - mold release to separate the first and second half of your mold

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Are any Alumilite casting resins food safe?
No, our resins are not approved for contact with food. Products that are approved for food contact include our Mold Putty and Plat55 silicone.

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Can food coloring be used to color Alumilite casting resins?
No, food coloring is a water based dye, therefore is not compatible with our resins. Alumilite dyes are fully reactive and will not bleed after cure unless die is not mixed in with resin fully. Oil based or alcohol based dyes also may work. Another option for coloring/tinting resins in to use Alumidust. They can be applied to silicone molds prior to casting or mixed in with resin.

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What Alumilite resin is best for machining?
While all of Alumilite's rigid resins can be machined, sanded, and tapped, we do recommend Replicator 400 as a first recommendation. It is a filled resin with a 6-8 minute open time and machines beautifully. Avoid mixing in excess air by steadily mixing for a minute or two and scrape the sides & bottom ensuring to mix it thoroughly.

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What causes Performance 65 or 80D castings to be soft and/or sticky?
In most instances, we find that users are mixing Performance 65 & 80 by weight rather than by volume. The proper mix ratio is 1:1 by VOLUME. Mixing by weight can cause soft and sticky castings. Pre-heating your mold (120-130F) is always a good practice to help facilitate the cure of the resin. Additionally, post curing the part in the mold for an hour at 130F can assist with full cure, especially for small or thin parts. If you have stickiness on the open surface, this could be a result of scraping unmixed resin out of the mixing cup at the end of the pour.

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What are the proper mix ratios for Alumilite Clear Casting Resins? Do they differ?
Yes, mix ratios are not the same for all clear casting resins. Improper mixing usually results in problems with the material curing properly, being flexible (not rigid), or being cloudy. Here are the proper mixing ratios for each of our clear products (also indicated on product bottles):

Alumilite Clear: 1:1 by WEIGHT (using a scale)

Alumilite Water Clear: 1:1 by WEIGHT (using a scale)

Amazing Clear Cast: 1:1 by VOLUME (using measuring cups)

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Are Alumilite Casting Resins waterproof?
Yes, once cured, Alumilite resins can come in to contact or be submerged in water. Many users actually use our resin to cast custom fishing lures.

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Molding
What is the difference between the High Strength 2 and the High Strength 3 moldmaking rubber?
The only difference between the two rubbers is the hardness. The High Strength 3 is softer and more flexible making it a better choice for one piece molds that contain deep undercuts or negative drafts. The High Strength 2 has better dimensional stability and is better suited for less undercut one piece molds and for two piece molds due to the stiffer nature of the cured rubber allowing it to line up better with a second half of a two piece mold.

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What types of molds can I pour Alumilite into?
With the proper release, you can cast Alumilite into almost anything. Here are a few examples: Silicone, Wax, Non-Sulfur Clay, Urethane, Latex, Plaster, Steel, Aluminum, and Wood. A thick paste wax or the Stoner Urethane Mold Release is required for non-silicone based items. If the mold is not made of silicone, the Alumilite resin is more than likely going to bond to it. So make sure the mold surface is not porous (cloth, wood, etc) and that you have an adequate layer of paste wax and/or Stoner on the mold surface.

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What is catalyst?
The catalyst is what causes the RTV to cure or harden. It is either tin or platinum base. The tin base systems are much more user friendly and will harden against practically any surface.

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Why is the surface of my silicone mold tacky?
Extremely low humidity level can cause some issues but most can be solved by simply waiting another day, or simply put some baby powder or talc on the tacky surface and it will all but go away almost instantly. Sometimes users will scrap unmixed Base from the walls of their mixing container after pouring, which is then deposited on top of the mold where it remains tacky.

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What rubbers are compatible to pour over one another?
You can pour tin over tin base, platinum over platinum base and tin over platinum base. You can not pour platinum base over tin base as the tin will inhibit (not allow) the platinum to cure where it comes in contact with tin (mold surface).

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How many parts will I get per mold before the mold starts to break down?
This all depends on the intricacy, what material you are pouring, and the detail of the part. Other factors are how many undercuts and how well the mold is cared for. It also depends on how often you are pouring, how hot your mold gets and if they are allowed to cool between pours. The following are estimates done with the use of a mold release using Alumilite resins.

M-2 ----------------------75-150

High Strength 3 ----------------------50-75

High Strength 2 ----------------------- 40-60

5 Minute Molding Putty --35-60

Amazing Mold Putty-----35-60

Quick-Set -------------------10-40

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Is there anything I can do to prolong the life of the mold?
Using mold release before pouring parts can double the life of your mold. You can also use/wipe Alumilite’s Silicone Oil on the mold surface before storing. Over time, the silicone oil will absorb into the silicone rubber mold to replenish some of the oil that has been lost during normal casting and demolding of your parts. The other option is to use a bake out process. A bake out process of the silicone rubber will help remove hardeners, plasticizers, and other materials that leach out of the casting resin materials that are on the molds surface. A slow gradual bake of 200 degrees F for 8 hours or 400 degrees F for 2 hours is recommended. This will also draw silicone oil within the rubber mold back to the surface to replenish what has been depleted. It is recommended to do this throughout the entire life of the mold rather than only when the mold dries out and is near the end of its life.

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What is vacuuming and why should I do it?
Vacuuming: A vacuum pump is like a vacuum cleaner. A vacuum cleaner is designed to pick up things such as dirt off of carpet using suction or vacuum. A vacuum pump is identical to a vacuum cleaner, except it will have MUCH more suction. A vacuum system is measured in the amount of vacuum it will pull. In technical terms, it is measured in inches of mercury. A common household vacuum will pull 1-2 inches of mercury. A good vacuum pump will pull 29-30 inches of mercury. A vacuum pump is used to suck the air from the mixed silicone to assist in pouring air/void free molds. The concept is that when we mix the silicone we mix in tons and tons of air into the mix. Ideally, we want to remove the air from the mixed rubber so it doesn’t end up in our cured rubber mold and we're really trying to avoid any air bubbles from sticking onto our original parts surface that would show up in our cured silicone rubber mold. When you put the mixed rubber that is full of tiny air bubbles under vacuum, it makes those air bubbles expand into big air bubbles which now have the buoyancy to float to the top and pop which removes them from your liquid rubber. If they remain small, they do not have the buoyancy required to float through the thick consistency of the rubber and get to the top. The thicker the rubber the harder it is for small bubbles to float and hence the need for the vacuuming rises.

Vacuuming Silicone: Our QuickSet Silicone, High Strength 2, and High Strength 3 has a thin enough viscosity the majority of air bubbles will rise to the surface without a vacuuming system. M-2 is too thick to allow air bubbles to rise. Therefore, you must pull a vacuum to assure no air is entrapped. Once your vacuum reaches 29-30 inches of mercury, the rubber will foam up. You will need a container around 4 times the size of the amount of silicone you are mixing. Once the rubber has risen, it will break (meaning to fall quickly). After the silicone falls, you will want to keep it under vacuum for another 2-3 minutes. Then remove the material from the vacuum and pour the rubber over your master. You may want to pull a second vacuum after the mold has been poured. This will remove any air that you may have entrapped while pouring. Remember, once the rubber has risen and fallen, it will not rise again. Our Vacuum Chambers are 10" x 12".

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How large of a mold can I make from silicone?
Our customers have both molded and cast very large items such as entire walls, bars, museum pieces, sculptures, trees, stairways, and architetural reproductions to name a few. Most of the materials are the same however the processes may change. For instance, you may paint or brush on the silicone mold making rubber rather than pouring. You would then make an outer shell to support the brushed on mold.

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What kind of detail can I expect from RTV silicones?
Silicones pick up the exact detail of the original including flaws and imperfections. So make sure your master is exactly how you'd like it prior to pouring. Fingerprints and scrim shaw are examples of very fine detail that are captured using our silicone moldmaking products.

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Are all your silicones FDA approved?
When mixed and cured properly, The Amazing Mold Putty, Five Minute Mold Putty, and Plat 55 all comply with FDA 21 CFR 177.2600 regulations. Even though these silicones can be washed, it is highly recommended to designate molds that are to be used for food as food only molds. DO NOT use a mold designated as a food mold for multiple casting mediums.

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What is the shelf life for liquid silicone as well the the mold making putty?
Generally speaking, our silicones have a very long shelf life. We've used as well our customers have informed us they have used our silicones very effectively after sitting for years. The official shelf life of all Alumilite's silicones are one year from the date of purchase in unopened containers. Moisture will react with some of the liquid silicone bases and cause them to thicken and go bad which is why it is important to store in ambient temperatures in a dry environment. Replace caps after using and avoid storing in garages or other non-temperature controlled environments. The mold making putties are very stable but will tend to slow down over a year from manufacturing. They still work but the open time and demold time will begin to extend. If it sits too long, the catalyst in the putty can lose it's reactivity (not allow the chemical reactions to do their job) and could lose it's ability to cure properly.

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How long will a silicone mold last?
Many factors need to be taken into consideration, so this is difficult to answer. What is the mold used for and with what casting medium? How large is the mold, the severity of undercuts in the mold? How is it stored? As well as the type of silicone used. Yields can vary from 10 parts to hundreds of parts. Average mold life expentancy for urethane cast pieces average between 30-70 pulls depending on all the factors involved.

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Is there something I can do to make my RTV silicone thinner and softer?
Silicone oil acts as a thinner of viscosity for unmixed silicone making it easier to pour. It will also slightly lower the hardness of your cured silicone system. The silicone oil can bleed from the cured RTV rubber if too much is added to the silicone, therefore we do not reccomend ever going over 10%.

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I need a silicone that I can paint on to a vertical surface to capture a relief, is there such a thing?
Thixo is an additive that can be put into High Strength 2 to increase the viscosity (consistency) of the mixed silicone rubber which allows the user to paint on and build up the wall thickness onto large molds or vertical surfaces. Initial coats sould be fairly thin to prevent air entrapment against the mold surface and secondary coats should be thicker and used to increase the overall thickness of your mold.

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How do I clean a mold when I am through with it?
If you are using one of the FDA silicones for food molds, do not use any harmful chemicals for clean up. Instead, wipe surfaces several times with a soft cloth or paper towel until a very thin film remains and then finish cleaning with rubbing alcohol or a degreasing (Dawn) cleaning agent and then rinse thoroughly with water. If the mold has some resin residue remaining, you can wipe out with cloth as above and clean with rubbing alcohol. The other option is to pour resin in the cavity in a thin layer and that will bond to the residue in the mold cavity pulling it out with the cured piece .

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Can I do anything to minimize/eliminate bubbles when making my mold without using vacuum equipment?
You will need an artist brush (natural) to paint a thin/skin coat onto the original. It is not the idea to cover the object with this first layer, but to push the silicone into the nooks and crannies filling in all the fine detail. This first layer or skin coat helps insure that no air bubbles will be trapped in the narrow recesses on the surface of the original. After the skin coat is applied, you will then embed your piece with silicone, taking it 1/4" above the highest point of the original. The silicone should be poured in one spot in the corner of a mold box from a height of about 12". This method is often called a "string pour". This allows the material to come down in a steady, semi slow stream as it falls into the corner of the mold box. This lets the material flow freely up and over the original, pushing some air pockets out of the way. The string pouring technique helps eliminate air that was incorporated into the silicone when it was mixed.

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How much by volume do I get in my 1 pound and 10 pound kit of Silicone, High Strength specifically?
There are approximately 21 cubic inches per lb of silicone rubber. This will give you an idea for whatever size mold box you need. To answer you question more directly ... 1 lb is approx 16-17 fl oz. The 10 lb kit is a little bit more than a gallon with the catalyst.

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Can the quickset silicone be used as a brush on in the making of an antler mold" from Products
Technically it would work, but the physical cured properties would not yield a flexible mold with good tear strength. We recommend High Strength 2 for brush on applications.

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Misc
Is Alumilite safe or toxic?
Alumilite is non - toxic and virtually odorless. First of all, we recommend you read any and all MSDS (Material Safety Data Sheets) and warning labels on any product that you use. All urethanes contain some type of Isocyanate. We have a very small, diluted amount of MDI Isocyanate, which was deregulated as hazardous and is not considered to be a hazardous material. Alumilite resins contains no mercury, (other than Alumilite Clear). Alumilite is not considered to be carcinogenic. Alumilite is safe to use in your home but is not recommended for children without adult supervision.

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What is the shelf life for Alumilite's casting resins?
1 year, however as long as the resin has been kept free from moisture, it may still be good to use for much longer periods of time. Resin that has been as old as 4 and 5 years old works with no problems as long as it has been sealed and free from moisture.

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What is the shelf life of silicone moldmaking rubbers?
Silicone rubber has a 6 months shelf life, but similar to the urethane resins, moisture is the cause of problems and shelf life. So store your silicone rubber in a clean and dry place to maximize the shelf life.

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Can I buy just one side of Alumilite or just catalyst for the rubber?
Yes. We typically stock extra catalyst for the silicone however if it is not in stock, expect a lead time of 5-10 days.

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Do you ship your products internationally?
Yes we typically use FEDEX for international shipping. The only items in our product line that can not be shipped internationally are the aerosol cans of mold release (specifically the UMR and the Stoner). Our shipping quotes do not include duties/taxes and brokerage fees that incur when products are delivered.

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What is durometer and viscosity, along with other terminology that will help me understand, what I am looking for, what I need and what I am getting?
Viscosity...Viscosity tells you how thick or thin a liquid is. The higher the viscosity number the thicker the liquid.

Durometer... refers to hardnerss ... How hard or how soft a material is. Shore 'D' durometer refers to hard materials and surfaces such as the rigid resins. Softer materials are rated on the Shore 'A' scale. The higher the number, the harder it is. How easy it is to flex a rubber or the flexible urethanes it is decided by both the hardness and the thickness as soft flexible materials feel harder as the part thickness increases.

Tensile Strength...is measured by grabbing two ends and pulling them apart until the part breaks. This measures the tensile strength and also gives you an idea of how elongation by measuring how much it stretches before breaking as well.

Pot Life...Amount of time you have after two components have been mixed together before your chemical reaction starts to occur and your compounds will begin to set.

Demold Time...The time you have to wait after it is solid enough to remove from your mold box or piece from your mold. At the demold time, it is solidified enough to handle but has not reached a full homogenous cure or it's full strength.

Cure Time...Your materials has reached "full strength and cure"

Fillers... Materials used to manipulate the resin to achieve a specific look, appearance, or function. There are many materials that act as fillers such as sand, aluminum powder, granite, calcium carbonate, microballoons, porcelain powders, etc. The percentage of filler recommended depends on the purpose and requirements of the finished piece. Typically 50-100% by volume is added to achieve the desired effect and not thicken the material so much that you are unable to mix and pour the material effectively.

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What factors contribute to shrinkage in molding & casting parts?
Shrinkage can be caused by a couple of things:

1. The type of silicone: Tin curing systems such as the High Strength 2/3 and Quickset will have minimal shrinkage from .25-.48%. Platinum based silicones such as our Plat55 will have zero shrinkage.

2. The casting resin: The majority of Alumilite casting resins have minimal shrinkage. Our filled systems have close to no shrinkage. You can add fillers such as mircoballons to resins such as AlumiRes or Regular to reduce or shrinkage, but it will thicken the resin.

Most users find shrinkage is very minimal and that it does not effect their castings. Users needing high accuracy will use a platinum silicone and in some instances will add a filler to their casting resin.

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My paint is not adhering, is it from my mold release?
If you used mold release, it is possible. The best thing you can do is use very warm soapy (Dawn or Cascade Gel). Then clean with Rubbing Alcohol and allow to dry. A primer coat painted on prior to air brushing or detailed painting helps adhesion as well. The Universal Mold Release can usually be painted over if used as a mold release if used in moderation and not sprayed heavily. Paint adhesion is also best if applied soon after pouring while the resin is still curing. Waiting days, weeks, or even months, may require abraiding the surface, cleaning with a mild solvent, and thoroughly drying before painting.

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Can I remove silicone and/or Alumilite from a work surface?
Alumilite has some very good adhesion qualities, even when you don't want it to. It is best to try and clean it while it is still liquid with paper towel or a rag very quickly using rubbing alcohol or any other mild solvent. Once it is cured it is very difficult to remove. Silicone bonds to nothing but another silicone for the most part but will absorb into any porous material such as clothes, carpet, and paper.

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What do I do if I am still having problems with moldmaking or casting projects and can't find answers in FAQ'S?
You have a couple of options. First and foremost, please call us at 1-800-447-9344 and speak with one of our technical representatives that will be glad to assist you. Our office hours are M-F from 8 am-5 pm. Your second option is to visit us on line. We have How To videos and are continually adding new applications on video for your convenience. An in-depth How To Guide, as well as a open moldmaking and casting forum, moderated by our tech's. There are also professional moldmakers and casters that answer questions, often times using similar applications that you may be pursuing sharing great advice and knowledge. So please visit us on line at www.alumilite.com or drop us an email at world@alumilite.com.

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What is the best/safest way to dispose of unused/expired casting material?
The best/safest and only way .... is to mix the components A & B together as if you were going to use it. Put it in an oversized container and do it outside if it is very old, in case the moisture contamination is so great it could create a rising foam and go up, over, and out of your container. Trust this... from someone who has experienced that, (smile) it could be a very bad thing on a kitchen table or inside floor!! You can then dispose of the cured piece if you take it out of your mixing vessel, or if it bonds dispose of the cured material with the vessel. An old ice cream pail, coffee can, paper cup (if very small amount) whatever you have on hand that you don't mind disposing of will work, no styrofoam of course as it will melt through that!

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What if I want to expand the volume of my resin?
Fill it! Fillers are dry materials that are compatible with Alumilite Polyurethane Resins. Fillers thicken and expand the volume of the casting plastic. It is best to not fill over 100% by volume, eliminating the chance of compromising physical properties to an extreme. Fillers can make the resin heavier or lighter, change it's appearance and reduce shrinkage. We only offer 3 fillers out of many that are available in dry fillers. Microballoons, tiny glass spheres used to thicken or extend volume. It will make the finished part lighter or float in water. Porcelain Powder, is a ground porcelain used to thicken or add weight. When it is mixed into White Alumilite Casting Resin, it will achieve a cold cast porcelain look to your cast pieces. Atomized Aluminium Powder, is powdered aluminum that will add weight. It is used to make vacuum molds where high heat is present, increases the heat service temerature from 225F to approximately 450F. Aluminum Powder stops shrinkage in parts where close tolerances are important. It will give an aluminum look to your cast pieces.

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Are Alumilite liquid dyes suppose to be this thick?
Yes, our liquid dyes are thick, some thicker than others such as the black. When purchased in the 1oz bottles, cut the dispensing tip half way down. This usually helps the product dispense easier. When the bottles begin to empty, store them up side down in a cup. This way the dye is always ready to dispense at the tip.

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Can you paint resin that contains porcelain powder?
You can paint it the same way as you have the non filled resins, however it would take away some of the porcelain appearance in the white resin

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How much volume can I expect out of 5 lbs of Microballoons?
5 lbs of Microballoons equates to approximately 3.5 gallons.

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