How to make my clay prototype.. plastic!?

[Thornekey]

Hi all I have made a small model out of clay, and i would like to make a mould for it, so i can make a lot of them and make them plastic. I have a basic knowledge of what to do.. (make a mould using the pink stuff (lol my terminology.. sorry!!! but i guess thats why i am here; to learn.), then put in the liquidy plastic, let it dry, cut it open.. tada..), but would definitely like to know what to buy, how to use it (links, etc), and roughly how much it would cost. The model itself is no bigger than an iphone, and I only want to make about 3 or 4 plastic versions.

Thanks in advance!

Nick

 

[claymore61]

Platinum cure silicon works for most plastics. Even clear acrylic.
you need to watch the shape etc.

any photos?

 

[Kubla Kraus]

Any pictures? What you are going to use the thing for may dictate what kind of material you want to mold it in. Also, make sure the clay you used doesn't have sulphur in it.

My first couple of tries I used MicroMarks Complete Resin Casting Starter Set. Maybe not the cheapest, but it has what you need for a first go at making something. You may need some pigment if you want your cast to be a certain color. If you don't need everything they sell the component parts as well.

Don't put too terribly much time into studying what it takes, most of it is just mix and pour. You'l want to know about stuff like registration keys to keep the mold halves aligned and pouring from a height to help get rid of air bubbles, etc. But if you do it and its crap, learn what you did wrong, and do it again better.

http://www.youtube.com/bitymoldsupply

http://www.freemansupply.com/video.htm

oh yeah, and pour spouts and vents.

 

[Thornekey]

Platinum cure silicon works for most plastics. Even clear acrylic.
you need to watch the shape etc.

any photos?

Hi claymore61, I will take a look at that. I dont have any pics atm, but I will take some tomorrow (its 2am).. hehe

My first couple of tries I used MicroMarks Complete Resin Casting Starter Set. Maybe not the cheapest, but it has what you need for a first go at making something. You may need some pigment if you want your cast to be a certain color. If you don't need everything they sell the component parts as well.

Thanks ill take a look at that too - i dont really care about the colour as i plan to prime and paint it

 

[CVWcreations]

Yeah you need to make a silicone mold of your prop, though you will need to treat the clay original or you'll find that the silicone will stick to the 'pores' of the clay ( you'll need to give it a really thin coat of vaseline), there's a few videos on you tube of the whole process.

 

[Thornekey]

this is the clay im using:



(sorry for the shonky quality..)

it says it air dries after a day.. so it should be pretty hard by itself..

hopefully its ok to use

 

[robn1]

this is the clay im using...hopefully its ok to use

That depends on what it's made of. Many clays contain sulfur which can inhibit the cure of silicone. It may be OK with tin based silicone if it's sealed well enough, but not platinum.

 

[Thornekey]

That depends on what it's made of. Many clays contain sulfur which can inhibit the cure of silicone. It may be OK with tin based silicone if it's sealed well enough, but not platinum.

Ive emailed the makers of it, and am awaiting a response. it doesnt even have say whats in it on the packet lol..

 

[Kubla Kraus]

that Micromark site also has an EXPORT version of their casting kit. looks like the only difference is no aerosol can of mold release.
Complete Resin Casting Kit (Export Version)

 

[CVWcreations]

Is that a good quality clay? You don't want it cracking as it shrinks, I always use das, its a good quality clay that you don't have to keep wet to avoid cracking.

 

[Alexfx]

This all totally depnds on your sculpt btw, if it's a simple shape with no undercuts you're going to be fine. I always advise mould release, I personally prefer paste wax, but it's not always ideal, sometimes spray wax is better, but for a rough surface spray wax is usually pointless and expensive. To give good advice on the moulding I'd really need to know what you're going to mould? Is it a phone case? Is it a bust? Is it full of holes to lock in the silicone?

GENERALLY 'the pink stuff' as you so eloquently put it, will be fine for most well released things as it is designed for moulding. There really are tons of moulding silicones out there and it's totally down to preference as to what you should use. Don't worry too much though, occasionally you can blag a free sample from companies too, let them believe you potentially want tons, ask for several different types for reaction tests and depending on the company you can get some free stuff!

fortunately, even if you totally goof on the release, you can generally soak the clay out, obviously you'll lose your sculpt, but that's why you're moulding it to begin with

then fast cast is your best bet for your 'plastic' casts. It's ****ing horrible stuff, and will rot your body away in no time, as it goes off it gives off cyanide gas, no one ever seems to mention this, but trust me, working professionally with it I've seen some really horrendous reactions to it. Wear gloves and a respirator, if you can't get a respirator at the very least do it outside on a windy day, then once it's out the mould, leave it to finish curing for a good 24 hours to make sure the oils are gone before handling it! Anyway safety lesson over, again as with the silicones there's are tons around, it's totally preference, most fast casts will go off against most silicones, so there's no real worry!

 

[Thornekey]

what i want to make plastic is just a little skull

 

[Thornekey]

Is that a good quality clay? You don't want it cracking as it shrinks, I always use das, its a good quality clay that you don't have to keep wet to avoid cracking.

well it was $5 for 1kg.. i dont know if that is good.. but it hasnt cracked and its completely dry now

- - - Updated - - -

This all totally depnds on your sculpt btw, if it's a simple shape with no undercuts you're going to be fine. I always advise mould release, I personally prefer paste wax, but it's not always ideal, sometimes spray wax is better, but for a rough surface spray wax is usually pointless and expensive. To give good advice on the moulding I'd really need to know what you're going to mould? Is it a phone case? Is it a bust? Is it full of holes to lock in the silicone?

GENERALLY 'the pink stuff' as you so eloquently put it, will be fine for most well released things as it is designed for moulding. There really are tons of moulding silicones out there and it's totally down to preference as to what you should use. Don't worry too much though, occasionally you can blag a free sample from companies too, let them believe you potentially want tons, ask for several different types for reaction tests and depending on the company you can get some free stuff!

fortunately, even if you totally goof on the release, you can generally soak the clay out, obviously you'll lose your sculpt, but that's why you're moulding it to begin with

then fast cast is your best bet for your 'plastic' casts. It's ****ing horrible stuff, and will rot your body away in no time, as it goes off it gives off cyanide gas, no one ever seems to mention this, but trust me, working professionally with it I've seen some really horrendous reactions to it. Wear gloves and a respirator, if you can't get a respirator at the very least do it outside on a windy day, then once it's out the mould, leave it to finish curing for a good 24 hours to make sure the oils are gone before handling it! Anyway safety lesson over, again as with the silicones there's are tons around, it's totally preference, most fast casts will go off against most silicones, so there's no real worry!

thanks a ton for all that info.. yeah! safety first! lol ive already had my chemical experience with fiberglass resin.. :S