Relief Casting with Microcrystalline wax - WarmGlass.com

Relief Casting with Microcrystalline wax

Use this forum for discussion on kiln casting, pate de verre, and related topics.

Moderator: Brad Walker

Post Reply
Debs Designs
Posts: 3
Joined: Mon May 05, 2008 3:35 pm

Relief Casting with Microcrystalline wax

Postby Debs Designs » Fri Mar 15, 2013 10:23 pm

Hi, I have been doing some casting projects using microcrystaline wax as the foundation for the mold material to be set up on. (I am making tiles). I made an open faced "box" with glass as the bottom and wooden sides set up with some clay on the outer edge to keep together and also to prevent the wax from running under. I took some vaseline and painted a thin layer against the glass thinking it would act as a release agent and barrier for the glass after I poured about 3/8" of melted liquid state wax into the box.

Trouble is, it didnt work. The wax is firmly "stuck to the glass"

So couple of questions. 1) do I even need to release the wax casting from the glass, as I will be pouring mold agent such as 50/50 over this to make the actual mold 2) If I do need to release the wax from the glass base, how best to do it 3) I wont be glass again as a base, what is best suggested in place of it. I need a rigid base obviously to make a flat precisely measured tile. Help is appreciated here........

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: Relief Casting with Microcrystalline wax

Postby Morganica » Sat Mar 16, 2013 12:51 am

Debs Designs wrote:Hi, I have been doing some casting projects using microcrystaline wax as the foundation for the mold material to be set up on. (I am making tiles). I made an open faced "box" with glass as the bottom and wooden sides set up with some clay on the outer edge to keep together and also to prevent the wax from running under. I took some vaseline and painted a thin layer against the glass thinking it would act as a release agent and barrier for the glass after I poured about 3/8" of melted liquid state wax into the box.

Trouble is, it didnt work. The wax is firmly "stuck to the glass"

So couple of questions. 1) do I even need to release the wax casting from the glass, as I will be pouring mold agent such as 50/50 over this to make the actual mold 2) If I do need to release the wax from the glass base, how best to do it 3) I wont be glass again as a base, what is best suggested in place of it. I need a rigid base obviously to make a flat precisely measured tile. Help is appreciated here........

Microcrystalline wax is a petroleum product, and so is vaseline, so if you combine the two you're essentially making an oilier wax. There are some silicone releases that might have worked, but wax is pretty pernicious when it comes to sticking. I prefer sticking my models down with a softer substance, such as earthen clay or disclosure wax.

Also, if you're making a lot of these tiles, it's probably easier to create a positive in very flexible silicone (look for a silicone with a "Shore A" rating of 30 or 40), secure that to your base and make your mold on that. The silicone will release easily, literally peeling out once the mold has hardened, and can be used over and over. You could make a basic flat tile that way, add whatever decoration you want in wax on top, and case molds with lots of variations using this method. It's what I do to create tiles like this:
wavetile.jpg

But to answer your questions:

1) Possibly, if you have few/no undercuts in your wax model and it doesn't "key" into the refractory mold material, because you might need some way to alleviate the suction between the two without damaging the mold. Sometimes you can wiggle it free, or if that doesn't work you can try excavating a small section of the edge of the mold, next to the glass, and forcing compressed air between mold and wax. Generally, though, it's better to remove mold+model intact.

If you do have anything that locks the wax into the mold, you absolutely need a release, because without it you'll damage the mold trying to remove it from the glass.

2) At this point the best way to get the model off is probably to use a hot blade to cut around the tile and remove the excess wax. If the tile is small enough you can work your way around the tile, underneath against the glass, with the hot knife and gradually free it. If not, put the assembly on a cold heating pad, or in a cold oven, and heat it until you can move the wax around on the glass and slide it off.

3) Wax or clay, the best bases I've found are made of quarter-inch sheet acrylic--I get four or five made up at a time in various sizes out of stuff I get cheap from the scrap bins at the plastic store. They're nice and smooth, rigid when they need to be (you can slide a wooden board under one when you need it to be absolutely rigid). They're easy to flex, though, which not only makes it easier to get molds/models off the base but also simplifies cleaning off the excess plaster when you're done--just flex the board and the dry plaster pops right off.

Eventually an acrylic base will scratch up to the point that clay/wax/plaster starts to stick to it. Once that happens, I wrap it in canvas or an old sheet and turn it into a base for making clay models.
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

Debs Designs
Posts: 3
Joined: Mon May 05, 2008 3:35 pm

Re: Relief Casting with Microcrystalline wax

Postby Debs Designs » Sat Mar 16, 2013 10:43 am

Thank you for responding to my questions. I guess you can tell when it comes to casting I am a newbie. Regarding the first part of your response to me about silicone, is there a website that I can go to for a tutorial on this? Or any type of resources?
As far as releasing the wax from the glass, I'm going to try to put the piece on a heatig pad as you suggested to heat it from the bottom as there is relief work carved into the wax that I do not want to compromise. I don't care as much about the base of the tile as I do the relief work. Please explain to me the acrylic base that you mentioned.
Wish me luck.

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: Relief Casting with Microcrystalline wax

Postby Morganica » Sat Mar 16, 2013 11:00 am

There are a lot of places to learn about silicone mold making. YouTube is actually a great resource, as are the websites for Smooth-on and Polytek, which manufacture the stuff.

Acrylic sheet is just plastic--clear or colored--that you can buy from a local plastics store. I use TAP Plastics.
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

Debs Designs
Posts: 3
Joined: Mon May 05, 2008 3:35 pm

Re: Relief Casting with Microcrystalline wax

Postby Debs Designs » Sat Mar 16, 2013 2:34 pm

Thanks for the help Ill be looking into all your suggestions

Joe Pfeifer
Posts: 24
Joined: Thu May 27, 2010 9:55 pm

Re: Relief Casting with Microcrystalline wax

Postby Joe Pfeifer » Wed Mar 20, 2013 12:15 pm

I great resource for you is to view Milon Townsend's DVD on Glass casting.

http://thebluemoonpress.com/index.php?m ... ucts_id=33


Post Reply

Return to “Kiln Casting”

Who is online

Users browsing this forum: No registered users and 2 guests

Warm Glass

2575 Old Glory Road, Suite 700
Suite 700
Clemmons, NC 27012
Phone: (336) 712 8003
Email: wg@warmglass.com

cron