Need Product Advice: Silicone

[Stormrider]

So I used the alumilite hs3 silicone. Its a tin cure, 600 bucks for a 5 gallon bucket.

Rediculous, I know.

I created my knee mold out of it, and got about 25-30 pours out of it.

Its shot to hell. It starting to look like old skin. Wrinkly and poor surface. I obviously cant go any further with it. Now the problem is kind of two fold.

1: Some of the things im making a mold of, are themselves cast. Such as I am making master darts, to make more molds, so i can pour them 10 at a time. The rubber/resins arent curing with the platinum.

2: Id like to do brush on application with it.

Well, my platinum isnt curing against it. So I needed a tin. Thus the HS3. But further, the tin cure stuff seems to not be giving me very many reproductions before it goes to hell.

Im getting to start some molds for my webley, and another for my knees. What would you guys suggest I try. Or is 20-30 just the most im going to get out of a mold? Whats the best tin cure that can be thixo'd

 

[LadySewforus]

Question from my hubby for you... Are you using oil clays container sulphur, such as romaplastilina?

(sp ?)

 

[Steelblitz]

-Seal any of your masters that you will make a mold of. Whether it be clear paint or an actual sealer made for such a purpose.

-30 casts with tin is about what I get with parts that have undercuts and take some flexing of the mold to get the part out of.

-Are you using a mold release? Something like Ease Release 200 is a good general purpose release spray.

-Can't help you on silicone recommendations without actually seeing the parts and knowing how you plan to make the mold for them. I use different silicones depending on what is being cast, how I plan to mold it, and how I will want to go about reproducing them.

 

[Stormrider]

Ladysewforus :
No, the clays not sulfer, and most of my paints etc arent. The big problem with the webley is many gun oils have minerals in them, that do contain sulfer. So thats the problem with the Plat Cure such as reb 25, thus wanting to know what the best tin cure is. Thanks for the response. If your hubby has any ideas, shoot them to me!

Steelblitz :
Well the part in question is the FP knees. In the fp thread I think theres a pic of it on the mold plug. But its a basic 2 piece block with the knees on a 'support hump' that gets pushed down into the mold block. The knees are in the lower mold block, basically kneepad down like your kneeling. The undercut is indeed about 2 inches.

I cant really seal the webley, for obvious reasons. But I dont want to use Tin cure. So im going to clean it the best I can I guess and then see if the silicone cures properly.

Will rebound 25 or a good platinum give me more pulls than a tin cure? I know the shelf life of a tin sucks, but wasnt sure about pull #.

Thanks!
Mason