Where can I find clear resin?

[MillenniumFalsehood]

Where is the best place to buy a clear resin compound? I tried Smooth-on.com and the only crystal clear resin is for industrial use only. I need clear-white, not another color.

[Umi_Ryuzuki]

BJB makes several formulas of "water clear resin".
http://www.bjbenterprises.com/
They can be a bit syrupy, so design your molds appropriately.

[macfrank]

The Alumilite folks make a water clear resin that cures very quickly, which can lead to trapped bubbles. Hobby Engineering carries it: Item 1686. I also tried Envirotex, with some frustrating results as I detailed here.

As Shinnentai mentions, you can avoid the problems with Envirotex by baking your silicone molds. The advantage of the Envirotex resin is that it takes hours to cure, so it's fairly easy to tap the bubbles out.

The clear Alumilite likes/needs a hot mold (at least 125F).

Frank

[MillenniumFalsehood]

BJB makes several formulas of "water clear resin".
http://www.bjbenterprises.com/
They can be a bit syrupy, so design your molds appropriately.

The molds I am making use a technique(the name escapes me) wherein you pour the resin mix into one half of the mold and rest the top half of the mold on the other half, trapping the resin inside. I am of course providing air escape holes in it. Would that kind of resin work well for that type of mold?

As Shinnentai mentions, you can avoid the problems with Envirtex by baking your silicone molds. The advantage of the Envirotex resin is that it takes hours to cure, so it's fairly easy to tap the bubbles out


The clear Alumilite likes/needs a hot mold (at least 125F).

Frank

I have never cast anything before, so will RTV withstand 125 degrees? I am just trying to be sure. I have an infuriating lack of talent for doing simple things. Probably because I don't do it right, is all .

[macfrank]

I have never cast anything before, so will RTV withstand 125 degrees? I am just trying to be sure. I have an infuriating lack of talent for doing simple things. Probably because I don't do it right, is all :roll: :D .

The molds I used were made from Alumilite RTV, so the answer is yes. 125F is just a little uncomfortable to the touch.

While heating the mold helps reduce bubbles, it's an iffy proposition without a degasser or some sort (either a vacuum chanber or a pressure pot). I wouldn't recommend clear casting as your first resin project. Get some regular opaque resin, make some pours with your mold, get some experience with the various casting pitfalls, then try the clear stuff. You can get Envirotex clear resin in most art supply stores (and it's fairly cheap) but you really, really need to bake the molds for a while to drive off whatever causes the Envirotex to not cure properly.

I've had excellent results with Envirotex and molds made from a silicone compound known as Siloxane. Micro-Mark sells a silicone putty that is easy to use, but it's a bit stiff and won't reproduce details quite as well as RTV (mainly because of the stiffness).

Frank

[MillenniumFalsehood]

Thanks so much for the advice! I am going to try the white first anyway, because I need to know how the finished prototype will look. What kind of pitfalls would I have to look for?

[macfrank]

Thanks so much for the advice! I am going to try the white first anyway, because I need to know how the finished prototype will look. What kind of pitfalls would I have to look for?

For clear?

- small bubbles in the finished product. Other than degassing the resin properly, you can reduce or eliminate the bubbles by making sure that the resin and molds are at the right temperature (the Alumilite clear - and possibly others - like it warm). The warm Alumilite cures quicker, but it's also a bit runnier at the beginning, so more bubbles float to the top.
- the RTV "poisoning" the resin so it doesn't fully cure (bake the mold!). This is particularly bad with the Envirotex. If you use RTV molds, make sure that the molds have had their bad mojo baked out of them.
- the RTV mold not being at a temperature that the clear resin likes (it'll take longer to cure, or may not cure properly)
- changes in color due to impurities leeched from the RTV. I have some clear parts, all made from the same resin, that vary from water clear to yellowish clear. The color being due to molds that weren't fully baked/cured/whatever.

[vaderman]

Try www.smoothon.com They have stuff called crystal clear that may suit your needs.


Scott

[Migmaker]

polytek has a clear as well, poly-optic 1410 i think..... even have,like others, a clearish rtv compound
Smoothon also makes a clear rtv. kinda milky in the example i saw today though, but you can see your master pattern all around.....this is definitly a good thing for 1 piecers
William