Resin Experiments

[marthaaleo]

I have been experimenting with epoxy resin and molds.  I've bought two molds and I was not impressed.  I have tried just about everything else with better results, including ice cube trays, silicone baking forms, plastic pill organizers, paint on latex rubber (you can pain around  a domino and get a nice shape) and molds made with 2 part RTV silicone putty.  The problem with the latter is, although it works like a dream, it gets expensive if you want to make anything big, like a bangle bracelet.  You can buy a kit to pour a silicone mold (Sheri Haab demonstrates this on her video) only it will run about $34.00.  

I was trolling around the Internet and I found artists who used silicone caulk to make molds.  Some mix it with paint, some with water, some with glycerin  and some apply it to a form in layers with no additives.  I tried my own version:  I got DAP 100% silicone caulk (not latex and no additives to prevent mold and mildew) and mixed it with a few drops of glycerin, added some cheap bouncy putty (you can get it at Oriental Traders for about $1.00 - they use it for kid's party favors) and I mix it in a metal pan with a metal spreader or spatula.  You have to be quick because when it starts to set up, it goes fast.  Then I smear some glycerin on my hands (Rings off or you can use gloves but it will stick without lubrication) and then build it up around the bangle (I've tried it with plastic and sterling silver bracelets) but leave an opening around the top so you can pour the resin.  It can be small because the silicone will be flexible when it cures, but not so small you end up pouring resin everywhere but the mold.

You can pop out the positive after a couple of hours(you could do it sooner, but I like to be safe) and let it sit a day or two before using it.  The silicone smells like vinegar.  I wear a respirator and goggles.  The mold ends up costing less than $5.00.

For the bangle you see here,  I poured some resin and added metal leaf with a toothpick.  Yes, it was messy.  Then I dripped some alcohol ink and swirled it in the mold with the toothpick.  I didn't want to mix it in entirely.  I took it out after 24 hours and let it cure another 72.  I used Envirotex Lite resin.

If you have ever finished a cast metal piece, resin is similar.  You have to sand off the seams and odd flakes and then go to finer and finer grits of sandpaper. ( I started at 320 and ended at 2000).  You can see every scratch in resin; it is not as forgiving as polymer clay.  Then you can buff it.  I read somewhere that stainless steel cleaner or Brasso helps to bring out the shine.  I tried it and it does.

Resin cast in a hard plastic mold comes out shiny, but you have to finish the back. I still have not found a way I like to do that.  That's another post, anyway.

Oh, and a great discovery!!!  White vinegar cleans up uncured resin.  Forget about the acetone and paint thinner.  Vinegar is way safer and way cheaper.





Martha Aleo

[burntspaghetti]

Oh man, I really love that bangle! I'm about to start experimenting with making my own moulds, so this is an awesome post to have come across.

[hello color!]

Do you use the whole tube of silicone caulk at once? If not, how do you keep it from going bad? I was thinking of using it uh basically instead of hot glue, but I only use a little at a time, so I wonder if a tube of caulk would last once it's opened...

Also, liquid silicone would not cost you $35 per mold, even if you used the most expensive stuff ($50ish for a 2 lb kit) - as long as you make a tight-fitting mold box since the wall doesn't need to be thicker than 1/4" for a regular smooth bracelet. Cheap stuff that Sherri Haab uses (Oomoo 30) would end up costing you about $5ish, just like the caulk, and it would probably last longer and give better results since the formulation is designed for mold-making... Oomoo 30 really is great if you don't have specialized needs and if you are ok with a 2-year shelf life. Of course, you'd have to buy the 2lb kit, which costs around $25, but it's really hard to stop with just one mold, anyway - so I'm sure you'd have no problem using it up

[marthaaleo]

OOOh, that's good to know.  For some reason I thought she used a whole container of a Smooth On variety and I priced it at my local store at it was 34.00.  I read up on the Oomoo and it would definately be better because it is a higher quality of silicone.  As for the DAP, you have to keep it sealed tightly and maybe I would use 1/2 a tube for a big mold.  But if Oomo has a shelf live of 2 years, that's way better.

Thank you so much!!!  I will try it.  



Martha Aleo

[hello color!]

I saw a video where she used a whole 2lb kit to make a mold of a pumpkin that she then used to cast a candle, so you might not be wrong. It's just easier to do that than to explain how to make a mold box and how to calculate how much silicone you need...

You can make a mold box using cardboard, boxboard, or foamboard + hot glue, though I read that you can also put it together using silicone caulk, so I want to give it a try since it might be less messy. I use all three, depending on what I have on hand. And, when the mold is ready, you just break up the box and take out the mold with your positive - e.g. bracelet - it's usually stuck to the silicone, and then, carefully take out the positive from the silicone.

You can also use clay to make walls and barriers, like plasticine - just make sure it doesn't contain sulfur, because sulfur inhibits silicone from curing. The good thing about clay is that you'll use it over and over and over and over again. You can use it to make the whole mold box, actually, though I don't think anyone does that. More often, it's used to help make 2-part molds, or skin molds with mother molds, stuff like that. Smooth-on has a lot of really awesome videos on Youtube linked from their site if you want to learn about more complicated molds... I don't have much use for it, but it's pretty neat to see molds of gigantic things, like a fireplace mantle, or a boat

[jerilynfoley]

Do you have a web site that has pictures of the steps?  I can't visualize what you are doing. The bracelet is wonderful.

[marthaaleo]

I do have a blog and web site, but I don't have these pictures or a tutorial on it.  You can do a resin casting and silicone mold search in YouTube and get some more concrete ideas.

Martha

[frankeknitter]

I have to try with the silicone caulk

[xx_Kellybean]

I actually tried that stuff off the sherri haub website, and it really didn't work as magically as it sounds. (At least it didn't for me, and it could easily be operator error ) but yeah.. I'll have to try this. Thank you for sharing

[JulieMom]

WOW!! I think the bangle is cool. Love the texture of both pieces!