Casting Resin, Can you thin the resin?

[Jamie Davison]

I have been trying to make a cast of some small pieces but the finer details are not coming out. I think it may be because the resin is too thick and so isnt getting into all the detail in the mould. Can the resin be thinned in any way? Can I just use water or is there any special thinner I need?

 

[defstartrooper]

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[Garthok]

This should be in the prop section as it is prop related. But don't use water! that's the last thing you want in your resin. Have you tried dusting your mold with talc? That helps pick up fine details.

I have to mirror what defstartrooper said, I also use polyurethane for casting and also never have problems picking up details.

 

[Nwerke]

Jamie, if you are using polyester resin you can thin it slightly with acetone. Not really recommended, however. If you are using polyurethane, get a thinner polyurethane. If you are using epoxy...why?! :lol

 

[Jamie Davison]

Im not sure what kind it is, it is this stuff:

eBay - The UK's Online Marketplace

I have never cast anything before so just tried this as it was cheap.

Ill try some talc on the mold and see if that helps.

 

[defstartrooper]

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[LeMarchand]

if your mold has tiny details, dust your mold with talcum powder. It reduces surface tension and the talcum will 'draw' the resin in those tiny spots.

 

[Jamie Davison]

ill try talc with the resin I have left and when that runs our (only bought a small amount) ill try the polyurethan resin. Thanks

 

[Garthok]

If you do try the talc in the mold it should be just a very fine layer. To dust a mold I use one of those brushes similar to what women use for applying make up. You can pour a bit in and tilt the mold around so it fills all the edges and the details. Then you can preferably blow out the rest, or tap the mold. But don't have a thick talc layer, you want it so it's barely even visible to your eye.

 

[BrundelFly]

MEK will also thin resin.

You will get some shrinkage.

Watch out its a carcinogen.

 

[SaberFreak]

If its a small enough piece I'd recommend using Superfine Milliput. You can press it firmly into the mold to make sure it picks up all the fine details.

 

[greatsaje]

Try preheating the resin a bit, I put my 2 parts in hot water for about 5 min prior to mixing to get it above 25c and I find that it tends to flow better, also for small peices I make the mold out of Silicon (it even picks up fingerprints) and if its not getting into the corners I just bend and twist the mold a little and hey presto...

 

[BGHUNTER]

What are you casting and what are the molds made from?.

 

[LeMarchand]

Try preheating the resin a bit, I put my 2 parts in hot water for about 5 min prior to mixing to get it above 25c and I find that it tends to flow better, also for small peices I make the mold out of Silicon (it even picks up fingerprints) and if its not getting into the corners I just bend and twist the mold a little and hey presto...

if you pre-heat the resin, remember that it kicks a lot faster and your worktime will drastically shorten.

 

[greatsaje]

If it's for smaller peices its worth the trade off. The stuff I use has a pot life of 4-5 min, with preheating I still get at least 3-4 min pot time. Also don't over heat it (I did 40c once) or the 2 parts wont mix right and will set like jelly.