CMC Gum Powder?
I was browsing through the new Delphi catalog and spotted a new product called CMC Gum Powder. You mix it with water and then with frit. They even showed it being used with a pastry tube (not this gal!). But I was wondering if anyone has tried it yet for powder wafer style applications?
* I've not used the Delphi version, but I have used CMC flakes to make my own CMC goop that I mixed with powder frit to create a paste. It came out fine except when I ramped too fast and didn't give the CMC a chance to burn off or dry before getting to the fusing temp. You can find CMC at pottery stores fairly cheaply and a little goes a looong way. I've still got most of the 1 pound bag I bought a couple of years ago and I've made a number of batches out of it.
* Thanks Mike. I think I'll buy some and experiment.
* Check prices with your local ceramic supply or cake decorating store before you do--a bag of CMC is usually pretty cheap. And yes, you can mix up CMC solution with frit and dispense it with a pastry bag, or spoon it out and mold it for powder wafers. If you've ever had a cake decorating class, it works the same way although the frit paste is tougher to squeeze out.
* I'll see if I can find it near here. I hate the shipping costs at Delphi. But living in the boonies of western Colorado, we're pretty limited. The UPS man is my best friend.
* Check with a local potter. Also, check with a local baker. It is used as a thickener for fondants among other uses.
As Mike said....a little goes a loooooong way. A four ounce jar of cmc powder should keep you happy for months.
* CMC is the basic ingredient in many products made for our craft. Klyrfire is a 3% solution (weak). Liquid stringer is a thick solution. There are others as well. Once you mix a thick solution, it is easy to dilute with water. Distilled water is best to use, and available cheap at WalMart.
* Does anyone put it in the fidge so it does not go moldy , or is this a problem. What is the best mixing % for the best mix that you have tried. I bet a small amount goes along way. Never used it and would like to try !
* If I remember correctly, I bought mine online at Seattle Pottery. ! pound for about $5.00. So far, I've used about 3 or 4 ounces and keep it in a tightly sealed glass jar. No mold yet.
* I can't give an exact answer. My goal is to get as thick a solution as I can get without lumps. Once you have this, diluting it is as easy as adding water or alcohol, and stirring. Adding some alcohol will probably help avoid growth of mold or stuff. For a spray medium, I like to add alcohol so it dries quickly. As a glue, I might not choose to do this,
I cook it on the stove with a wisk. I stir it with the wisk and simmer until the lumps are gone and I like the consistency. Since proportions are not critical, eyeballing works for me. With any organic binder, you want to use as little as necessary. The exception might be liquid stringer, where the thickness is doing a lot of work for you. I make a gallon and keep it around for many seasons. Others report mold problems. I never had any.
* I have never had a problem with the CMC powder going moldy. Have had some for years.
When making the mix, I add a few drops of Clorox and have never had a problem with mold. I use quite a bit of it, so it turns over fast, but I have had some mixed jars as long as 4 months without mold. NOTE: I do get a slight amount of what I believe is mold on the lip of the jars, but this might just be dried out CMC.
Just noticed Bert's mixing comments. Let me simplify.
I mix 4 level tablespoons in a mayo jar containing 1 pint hot water. Mix well. Break up large lumps as best as you can, but don't worry about medium and small lumps. Let sit for 3 days. Lumps gone and you have CMC solution. (In the initial mix, throw in about a teaspoon of clorox).
* Well after all this time, I think I should get out my package that Cynthia and I bought in Portland and go for it. I have had some great ideas for some time now!!!!!!!! Thanks everyone. Fun starts with ideas soooooo off I go.
* CMC comes in different concentrations/strengths and stores can sometimes change suppliers, so the same recipe won't work for everyone. With the batch I have now, 4 level tablespoons in one pint will make a solid brick--it took a gallon of hot water on top of the initial pint, finally, to dilute it to the thickness of very slow molasses. That gave me a LOT of CMC.
You have to experiment a bit--I start with a tablespoon in the bottom of the bowl, pour a pint of very hot water with about six drops of bleach and let it sit overnight. Check it in the morning, and if it's the right consistency, I bottle it. (I don't store mine in the refrigerator, it stiffens it too much and I'm too impatient to wait for it to warm up--the bleach takes care of the molding problem)
If it's too thick, I add more hot water and let it sit again--mixing this stuff doesn't get you far. If it's too thin, I heat the mixture in the microwave (but not to boiling) and pour it over more CMC, let it sit overnight again. As long as I keep track of how much CMC has actually gone into the bowl, so I can mix it in the right quantity next time, I'm fine.
* Here is the link to the instruction sheet on Delphi. It's a place to start at least.
* I notice Delphi's instructions say 1 part cmc to 2 parts powder frit. That should state 'approximately'.
If your mixed 'glass clay' is too wet mix in a little more powder & if it's too dry mix in a little more cmc (or your choice of binder, lots of other things available). To sculpt it's easiest if it's the consistency between pie crust & stiff cookie dough. Wetter than that your forms will sink in on themselves & drier is a tad more difficult to smooth out any cracks while sculpting it.
* Thanks for all the great advice. I'm looking forward to some experimenting.
* Barry (Bookie 13) indicated to me some time ago that a little glycerine in the mix will help with keeping the ease of moulding.
* As far as how to apply the paste I see references to using a pastry tube what other applicators have folks used? I'm looking to layout a bead maybe a little thinner then a glass rod. I was thinking a restaurant style ketchup bottle are there other squeeze bottles out there? If they came with an assortment of tip sizes theat would be great. I'm thinking with a dremel you might be able to make custom pastry tips. Just on a smaller easier to manage scale.
* I've gotten squeeze bottles from beauty supply stores...they're used for applying hair color. They're plastic so you can cut the tip off to various sizes. But I find using a pastry bag is much easier for me to handle...it's easier to squeeze as I don't have as much strength in my hands as I used to. The hair color bottles are about the softest plastic bottles I could find and they were still too hard for me to squeeze. I just get the plastic disposable pastry bags they sell like in box of 100, but I think some people buy the reusable ones that they clean out and reuse. The plastic ones do have a tendancy to spring a leak now and then, but I just slap a piece of duct tape over the leak and it holds till I'm done! You can get pastry tips in a variety of different sizes, but like you say, I think even if you couldn't find the size you could customize one easy enough.
* I use the pastry bags, too. My favorite are the disposable plastic, but I've got a couple of sturdy cloth bags that work well, too, just need a bit more cleaning. I use them when I've got a lot of glass paste to apply because you can overfill them and they'll never, ever leak. Pastry bags easier to control and not as hard on your hands, but the real reason I love them is the cleanability: You just turn the bag inside out and rinse.
If you go to a hobby store, in the cake decorating section, you'll find a fair assortment of tips. Much better, though, to go to a confectioner's supply. If your city is large enough there's probably at least one. They have an amazing selection of pastry tips, and if you tell the employees what you want to produce they can usually suggest the best tip to use. If your paste is stiff enough, the shaper tips (leaves, petals, etc.) give you a real headstart on sculpting.