Making a mold with latex?

Eagleskull

Active Hunter
I was wondering if you can make a mold out of liqurd latex? Trying to make a mold of small clay sculpture so i can make a hard copy out of resin and was wondering how to do it? I hear it can be done but after a while the latex loses detail and the copies become smaller. But was wondering if anyone has tip and what not.

Thanks for your time
 
There are loads of tutorials on the net dude.

A lot of people tend to cover the original with latex, leave room so you take the skin off afterwards. Let it set.
Carefully take it off and bingo, one latex skin mould of your original.

Then use sand to support it whilst you pour your liquid into the mould.
otherwise the weight of the liquid will distort your mould. Depends what your trying to copy though.

I've never done it but need to learn as I do Palpatine and want to make my own face casts
 
Latex do lose some size as the latex cures. Normally I only do a snap mold if it's a really the only way I have of doing something or I'm too tapped out to buy a good tin sil or platinum silicone. Preferrably I'd go for a silicone.....Maybe a gel10 would be better than a latex mold for you. You can't really go wrong with platgel 10 as it's a 1:1 mixing ratio by weight.

Anyway. When sculpting when you will be molding in latex, factor in at least 10% for shrinkage <you can get between 10-!5%>. Place whatever object you are molding on smmoth flat surface. Like a nice piece of acrylic. Hopefully what you're sculpting will have a flat bottom. Once secured to the acrylic seal the sculpt with an acylic sealer like Krystal Klear, at least 2-3 coats and spray again with a dulling spray, this will stop the liquid latex beading up on the surface. Paint your latex on in layers waiting for each layer to dry completley before the application of another. You can force the drying by using a hairdryer. Do at least 6-8 layers with thin latex as this way you'll capture all the details. Then you can do a few layeers with a thicker batch thickened with a thixotropic agent you can get from the same place you ordered your latex. You can even add layers of nylon <as in tights> in between these final layers. As the fabric will creat a bond between the layers of latex and increase the mold strength and ultimately the life of the mold. But your mold will deteriorate especially when using resin. Once the mold is done. Don't peel it off just yet. As you need a jacket to go with it. Make A box wall to surround the mold and then mix up some plaster of paris or if you have the time you can use fibre glass. Pour the plaster in the box and wait for it to cure.then you have a mold and a support jacket for it too. If you go the fibre glass route you don't need to make the box wall, just spray release on the outside of the mold and simply lay your mat on your mold and wet it out with the resin. Do 2 or three layers and you're good to go.

You could always go the waste mold route which is how I do all my pieces that need a fine polished finish. Make a plaster mold of your piece, clean the mold. Spray the interior with grey primer and then add a wax release to it once dried. Then you're ready to fibreglaas. Once the piece is finfished and the fibre glass cured fully. You smash the mold carefully. Sounds madness but it's worth the hassel, as you're left with a pice that can be sanded and filled and refined until you're ready to mold in silicone.

Hope this helps explain the latex molding process and the other bits help you decide whether it's worth it or not. As I said Silicone maybe more expensive but it really does provide you witha greater quality of mold.
 
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All my projects ive done ive used liquid latex. Its a very easy process but can be time consuming. First layer you paint on thin and let dry completely, i then between layers use CHEESE CLOTH for added strength. Paint on with a throw away brush, and let dry completely between layers as well. Im starting to use RVT's now for my large scale projects but for the smaller stuff, latex is alot cheaper and more cost effective. If your going to use resin in your latex then I would just spend the extra money and go with the Rubber molds as they will last alot longer and the Latex isnt all that great for that kind of stuff but it will still work.


-Tim
 
if you are worried about the mold shrinking right away, you could always just make the original larger than it needs to be to accomodate for the loss of material. Depending on where you get the latex and what kind it is, it may just be more effective to get some RTV silicone from a place like smooth-on. You could also call hobby shops and ask if they carry that kind of thing. It's not that expensive when you think about what you can do with it. Maybe a mold takes $35 worth of material. But if you make a couple castings worth $15-20 a piece then you could always sell a couple to make up for it.

I know a lot of people do projects just for themselves and eventually because of interest end up doing small/limited runs to make up for the investment. A way of helping everyone else out and yourself

-=QuinN!
 
Using the cheese cloth will also help keep the latex from shrinking so much. I think the latex with less amonia dosent shrink as much. Also adding paint to the latex seems to help some too.

~Mel
 
The link should work just fine as it is Mr Palpatine;) if not just try working through the tap plastics site until you get to the vids. I really must try and sort you out with a new set of prostetics mate later in the year if you're still up for it?
 
I really must try and sort you out with a new set of prostetics mate later in the year if you're still up for it?

Yes, yeessss :)

Please get in touch dude. I'd be well up for it.
I've got a load of gelatin and plaster/clay etc but I've been too busy with Bek's Zam to sort anything out, but yes, yeessss
 
Gelatine's good for prothetics mate but can be a bugger to work with when applying if you're new to it, the good thing is you can blend the edges away quite easily and veryconvincingly, though I would say it would be a one shot deal each time you use the appliance.

I will be in touch about it mate so don't worry, I just have that much going on at the mo' it's not funny plus several movie projects in the pipe too for which I'm heavily involved in the pre production side of it with set design and the like, but I will try and find time to knock out a few decent ESB and ROTJ and maybe EP3 Palpy bits for you.
 
Made the mold yesterday and came out perfect, the way i wanted it. First mold ever in my book :) Thanks again for all the help. Now time to buy some resin and cast :D
 
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