gun guys I need help

[BIKERFETT]

Is it possible to make a plaster cast of a resin gun in order to reproduce it again in resin. I know that I can make a mold out of silicone based fulcanized rubber but It is expensive. Any help is appreciated. There are a couple of projects that I would like to tackle.

Thanx
Chris

 

[jonnytrooper]

no

 

[Stampedemag]

No you can't cast it in plaster or no you can't put the resin in plaster? Personally it has always been hard/soft soft/hard but I have gotten hard/hard to work i.e. making a plaster cast of a plaster piece.

I don't have experience with resin. I am just starting to work with the stuff. Will it not sure in plaster? If it will as long as there are no undercuts what would be the problem?

 

[BIKERFETT]

I guess I may not have said what I meant right. I am just learning to reproduce a couple of guns. I was wanting to know if I could make a mold of a gun out of plaster and then make resin casts of it out of the plaster mold. THis is my first time at this and would like to benefit from the vast knowledge

 

[Rodann]

I don't think you'd be able to get the resin parts out of the plaster mold without destroying the mold. Plaster can be pretty brittle, and there's no "give" between those two materials. Hobby Lobby sells a $50 resin/silicone molding kit, if your pieces are small enough. They sell the silicone by itself, too.

 

[BIKERFETT]

<div class='quotetop'>QUOTE(Rodann @ Jan 13 2007, 09:44 PM) [snapback]1396847[/snapback]</div>

I don't think you'd be able to get the resin parts out of the plaster mold without destroying the mold. Plaster can be pretty brittle, and there's no "give" between those two materials. Hobby Lobby sells a $50 resin/silicone molding kit, if your pieces are small enough. They sell the silicone by itself, too.
[/b]

Do they sell the silicone in bulk to mix and make a mold.?

 

[Stampedemag]

You can also go to Pearl's art supply. They sometimes carry Smooth-On products. Silicone, resin, etc. I would call first because some stores don't.

 

[BIKERFETT]

thanx never heard of that store before though

 

[exoray]

You can always go with a urethane rubber mold as well if cost is an issue, but you will need lots of mold release if you ever want to get the parts out...

And last but not least in molding you get what you pay for, silicone is exensive but it's also FAR superior for resin casting...

 

[Blad]

Absolutely agree with exoray.

Also, even if you could get your resin gun out of a plaster mould without damaging the mould (which would be next to impossible) you would have to use polyester resin to cast as urethane resin will react with the water left in the plaster.

Latex is a cheap mould making material but will shrink.

Alginate is too fragile and will tear easily

Plaster is good, but only for making flexible parts out of latex/silicone.

If you want to cut down on the amount of silicone you use you can make a relatively thin skin mould using a thixiotropic (sp?) agent for the silicone and then make a mould case out of plaster, plaster bandages or glass fibre.

 

[Rodann]

I wouldn't say "bulk". More like 14.5 ounce jars. $20-30, I think. About the size of a jar of Noxzema.

 

[Treadwell]

Added a line to the thread description, as you're really looking for casting advice, not gun advice.

 

[Weazel1]

Actually, you can use both silicone rubber and plaster to make a mold. You start by brushing a thin (but not too thin) layer of rubber on the part you want to replicate. After it sets, you surround the rubber with the plaster. This gives a durable mold without breaking the bank.
I realize this is a gross simplification of the process. There are still mold boxes, pour holes, mold seperation lines, etc. to consider. But using the rubber for the details and the plaster for support is far cheaper than a solid rubber mold.

Brian

 

[bigboba]

There is a great book available that shows this techniqueof silicone and plaster molds ( well worth getting for this and other molding techniques) called the prop makers Molding and casting Handbook, its by a guy called Thurston James who worked in theatre and wrote the theaterprops handbook you are bound to get one on e-bay
Steve