Resin Casting

[mickc22]

Nice job...

Mark that\'s looking sweet!
I\'ve been playing about with the old resin too, the problem I had (didn\'t notice it until I did the casting) was bubbles in the mould, resulting in little bobbles on the cast. Got that sorted now tho.
there are a load of videos on the Freeman Supply website, which where both educational & entertaining.

Roy Hunt (Planetfigure) was at Euro Militaire he was working with a rubber that could cast a resin torso/legs, like yours Mark, in a one piece mould. Haven\'t got round to talking to him yet, might be worth an email tho

 

[Klute]

Cheers guys.

Ive got a pressure system sorted (compressor and old pressure cooker) but the one I tried I cast at 80 psi and while there wasnt a single bubble the pressure was too much and pressed the resing into the mould where there were air bubbles under the surface cos I didnt vac it.
I think I would have to vac the mould the pressure the cast.
Ive since read that 40 psi might be enough ??

 

[Durham_red]

What you need to get is a vac chamber.

Though the problem with these is that they can be expensive

All the RTV casting I have done, I\'ve used Smooth cast 305, a single piece Rtv mould and a degassing vac chamber.

I just need to get one for my house now

 

[Klute]

Yeah its just I want to keep the cost down for what is essentially me messing around.

 

[Garyo]

Try making the rubber mold using the pressure pot as well as the resin cast. Unless you are really airating your rubber when you mix it this should fix the bubbles in the mold problem and you don\'t need to set up a vac chamber Who\'s rubber are you using?

Garyo

 

[Klute]

Flexil s rubber. It seems ok but holds small air bubbles through the whole cast.
That was the problem when I first pressure cast.The pressure pushed the resin into the mold popping the bubbles and hardening as lumps on the casting.That was 80 psi though but I think 40 psi would do the same too.

So you would pressure cast the rubber too. I was thinking along those lines.
Would you recommend a different rubber.The one I used is very \"soft\" and I think I could get away with something harder though ??

 

[Garyo]

I use Tinsil 70-25 or Silicone Inc GI-1000 and cure them under pressure 40-50psi works pretty well. They both have a good shelf life. I also have used OOMO 30 from Smooth-On, it\'s easy to mix 50/50 part A and B, but only seems to have a six month shelf life. So far the only down side I\'ve expereinced is it will force the rubber into any and all crevaces.

Garyo

 

[Klute]

Cheers Garyo I will give that a shot with the next batch.
For some reason I was imagining the rubber bouncing back when the pressure was off.lol

Ive been sculpting now to counteract the rubber moulding becuase the nature of it to get every detail. Rounding out sharp cuts etc.