Ghetto casting

[Boba Frett]

<div class='quotetop'>QUOTE(BlindSquirrel @ Mar 6 2007, 06:03 PM) [snapback]1433217[/snapback]</div>

What's the concensus? 4 drops of Glycerine or 50 drops per tube?
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4 drops of Glycerine and 4 drops of latex per tube.

 

[BlindSquirrel]

I just read that someone used Naptha to thin the silicone mixture (1:1) to a honey-like viscosity for brushing. A regular coat is applied after it dries.

Has anyone tried this?

 

[jason1976]

Dumb question, but what constatutes a "drop"?

I've tried this a few times now, and I love the molds I've been getting, but they're taking forever to set up, and I think it's because I'm not putting enough babylax in, so when everyone say's "1 drop of babylax, and one drop of paint per 1/4 tube of silicone" what is a "drop". (Oh, and yes I am making sure not to make it any thinker then 1/4" think per layer, so that's not my problem . )

 

[BlindSquirrel]

I just tried that formula and after a week it's still sticky and barely solid. If the Glycerine is a catalyst, then I'm leaning toward the 50 drops ratio.

 

[SgtFang]

I don't know how many places still do this, but you could try calling around to various silicone suppliers and see if anyone would be willing to send you a free sample of actual molding silicone. I know Silicones Inc. here in the States used to do that, but too much word got out, and they finally started charging for them. :$

-Sarge

 

[Boba Frett]

I just tried that formula and after a week it's still sticky and barely solid. If the Glycerine is a catalyst, then I'm leaning toward the 50 drops ratio.

I ran across this myself awhile back, it has to be 100% silicone, some tubes will have Bioseal added to it, and it will never dry.

This is one I made with tube silicone, 4 drops baby lax, 4 drops latex paint per tube.

 

[Sporak]

That's right...any silicone with additives will take forever if ever to cure.
Get the cheap stuff...100% silicone and Babylax now called "Pedia-Lax" by the way...Liquid glycerin suppositories.These are really eyedroppers and make for easy drop measurement.I add about 5 drops to mine just to be safe.

I have a project in the works right now and it's working great!

This technique works nicely for a one off piece that you're going to re work before making your final mold in the good stuff.

 

[Sculptzor]

I just read that someone used Naptha to thin the silicone mixture (1:1) to a honey-like viscosity for brushing. A regular coat is applied after it dries.

Has anyone tried this?

I used this a couple of times for small resin pieces. I thinned the caulking with naptha for a detail coat then used acrylic paint with the caulking to back it up. I don't know what brand you guys use that needs glycerine as a catalyst but a dash of acrylic and the caulking would set in 5 minutes top. Maybe my "drops" were too liberal? Either way make sure to use some form of mold release because it does not come off as easy as the real stuff. I wouldn't recommend it for anything important but it makes a cheap waste mold.

 

[Boba Frett]

I used this a couple of times for small resin pieces. I thinned the caulking with naptha for a detail coat then used acrylic paint with the caulking to back it up. I don't know what brand you guys use that needs glycerine as a catalyst but a dash of acrylic and the caulking would set in 5 minutes top. Maybe my &quot;drops&quot; were too liberal? Either way make sure to use some form of mold release because it does not come off as easy as the real stuff. I wouldn't recommend it for anything important but it makes a cheap waste mold.

I haven't used any mold release at all, and haven't had any trouble, the glycerine helps it to not stick.

 

[jason1976]

Well I've tried this twice now, and I finally have an ok mold, but I still think the description "drops" is a bit vague. I used 4 "drops" of acrylic paint, and 4 "drops" of baby-lax, per tube of 10o% GE silicon. And, it took over 2 WEEKS to set up. So the next time, I used a little more then a dropper (maybe it was two droppers I forget) of the baby-lax, and a little more liberal "drops" of paint, with the same silicon, and wall it set up a little faster, is still took at least a week to be able to demold with out it being uncured inside.

Oh, and I've been careful not to put it on too thick.

So why is mine taking so long to set up? What constitutes a "drop"?

 

[Sporak]

I usually use 6 drops or so of baby lax...and a squeeze of acrylic paint
I don't measure the drops of paint...

Make absolutely sure you use silicone with NO additives in it.
Other silicone is also 100% , but will have a secret ingrediant.
When that happens it takes a long time to set up.

Smell your silicone...if it smells like vinegar it's probably fine...but if the smell is masked, minty or menthol...it has something else added to it.
This is my experience anyway

So why is mine taking so long to set up? What constitutes a "drop"?

 

[jason1976]

Well mine is 100% clear silicon, by GE, and it stinks. (kind of like vinigure.) So I guess I'll just keep playing with the amounts of Baby lax and paint.

Now I just need to figure out what I want to cast with. I got so excited that I made my fist mold with this stuff, that I actually tried plaster of pares, but the mold pulled away from the sides of the plaster jacket. (even though, the mold and the jacket are bother REALLY thick. ) Then I got really desperate, so I tried BONDO. LOL It kind of worked, but I need to use a lot more, and it to think to get into some of the under cutting, but it was a fun little experiment.