Need rubber advice super quick

[radioscooter]

I usually only work with the Alumilite RTV rubber when making molds and am finally graduating into a larger resin order direct from smooth-on and they have about 30 different RTV mold rubbers available. Can anyone reccomend a specific one quickly?

Thanks.
-S

[casimir]

I'd like info on this, too. I was looking at the smooth-on site and just got confused.

C.

[Wild Willy]

For my molding I prefer Silicon rather then RTV.
I use OOMOO 25 Silicon based rubber compound.

I started off trying the RTV type stuff but was disapointed because sometimes whenj I mixed it it just would not cure properly, I don't know what I did wrong, but it ended up sticky and somewhat crumbly.

The Silicon is easiest I've ever tried when casting resin pieces, it grabs every tiny detail and it easy to remove the cured resin parts from.

Hope this helps.

Will

[Figuremaster Les]

OOMOO 30 is what I have. No problems as of yet.
I want to try the 25...
I can't say much about the chemistry of any of it, but that OOMOO is terrific stuff!

[casimir]

So Les, tell us more about OOMOO 30. How long does it take to set? Does it require release agents? Details, man, details!

C.

[Figuremaster Les]

Here's what I know about OOMOO 30 Silicone Mold material.

1- Takes overnight (8+ hours) to set up.

2- I used the "official" Smooth-On superseal sealing agent that came with my lil try-it-out kit, and sprayed the original and then used their Universal mold release on the mold just before casting. Not a problem at all. I did test the material beforehand and it will tear if you go at it just right with a lot of force, so it's not the most tough material.
But it makes killer head molds and I have cast about 10 heads from the very first one I made with only one minor tear in the mold that made sense (It was an odd deep pocket over an ear between the ear and the hair...) But after casting, the "hole" was not at all that bad an issue.

Bottom line: I like it! Depends on how many things you are casting and the basic wear on the mold I would guess.

Since I haven't tried on a larger area, a body for instance, I wouldn't know about larger mixes.

I did have plenty of time to properly mix the two parts together (EASY 50/50 volume ratio mix) and it poured very well. I even "painted" the surface of the face first, to get all the details, then poured the mold after re-inserting the coated head back into the cup.

Hope that info helps. ;D