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Homemade Reusable Mold Material

Posted by Belgianpup Wa/Zone 8 (My Page) on
Mon, Nov 8, 04 at 17:03

I tried this mold material from a listed website, eventually making changes & making discoveries. This stuff is pretty good, although it is sensitive to heat. I haven't tried it for plaster or concrete yet, so please consider it as experimental.

The mold material feels like a very dense, foamy latex, flexible, but quite sturdy. I tried to tear a simple mold and couldn't do it.

If you're going to start mixing this stuff, do it when you won't have any interruptions & aren't hung over or operating on lack of sleep. Don't get sidetracked or you will regret it. (Ask me how I know....)

And don't try to rush things and add all the ingredients at once, or add them in another order. I paid $16 for a gallon of glycerin through my vet & wasted quite a bit.

!!!DENATURED ALCOHOL IS EXPLOSIVE!!! DO NOT ADD WHILE ON THE STOVE. DO NOT SMOKE WHILE USING. It is available from your hardware store. It is NOT rubbing alcohol. IT IS EXPLOSIVE!!!

I have only used silicone mold release on it, so far.

RECIPE for large batch (small experimental batch at end of post)

4 1/2 pounds dry Gelatin (my source says use flake gelatin, but I couldn't find any, so I used regular unflavored gelatin from a health food store.)
9 cups of cool Water (2.25 qts.)
13 cups Glycerin (3.25 qts or 9 lbs)
1 oz. Denatured Alcohol

Put the measured glycerin into a pot over LOW heat & start it heating. You do NOT add it to the gelatin unheated.

Pour the water into a large cooking pot & add the gelatin. Start mixing immediately & keep mixing until all the water & the gelatin is thouroughly mixed together (I used my hands). DON'T STOP mixing or it will separate & congeal in layers. When ready, the mess should be consistent in quality.

Place the pot over LOW heat & start stirring when it begins to melt, and keep stirring until the gelatin is all melted and free from lumps. Then add the heated glycerin and stir until blended. Continue to stir until all ingredients are thoroughly incorporated and REMOVE FROM STOVE ENTIRELY. Now add the alcohol and stir until thoroughly blended with the rest of the mixture. It is now ready to use, & should be used while warm.

NOTES:
Cooling the new mold can be accelerated by placing in the refrigerator.

When buying gelatin, be sure to SMELL it -- if it doesn't smell like JELLO, it isn't gelatin! A health food store sold me CORNSTARCH as gelatin, so beware.

I would tend to use dedicated utensils for this project.

The original recipe said to cook in a double boiler, but I didn't have one large enough, & didn't want to mess with 2 pots with rocks or marbles between, & just kept the temp on the lowest temp of my electric stove. It also said to include a pound of glucose, but I made mine without it, since I couldn't find any. Yes, glucose is a form of sugar, but since it didn't SAY to use sugar, I didn't. I suspect it was added to increase bulk, but I don't know for sure, & it works well without it.

To make into another mold, just put back in the pot and heat at LOW temperature. DO NOT add water.

This material can be used many times. If it starts getting debris in it, just form a sieve made from wire window screening in a funnel shape and while the material is melted, pour it through into another container.

_____________________________
(1/3 sized recipe for trial)
1.5 lbs gelatin
3 cups cool water
4 1/3 cups glycerin
1 Tablespoon denatured alcohol
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'Pup


Follow-Up Postings:

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RE: Homemade Reusable Mold Material

Good Morning 'Pup!

What a cool technique! I'll have to give it a try. What kind of slip is this kind of mold intended for? Do you think it would be good for POP? What kind of release agent would be good for it? Can the mold material be cut if you create a surround mold for an object?

I love that it is reuseable. How much mold material do you have by volume after all the cooking is done? Does the residual material stick to the pot you cooked it in or would it peel off fairly easily? Enquiring minds want to know... ;)

If the test amount of denatured alcohol is 1T, does that mean that 1oz of DA is equal to 3T of DA? Don't have a scale....

Thanks so much for this information.

GM


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RE: Homemade Reusable Mold Material

To tell the truth, I haven't used this material much. And there wasn't much info beyond making the material itself.

I used it on a leaf, which worked okay (the heat apparently wasn't a problem, which was a bit of a surprise), but there were some bubbling problems on the surface. I don't know if this is a problem with the material, or if I did something wrong. Maybe just some stirring a bit more after removing from the heat would work them out.

So far, I have just used a spray silicone used in plastic injection molding as a mold release (it dries on the mold). I haven't used any of the other common types, such as oils, PAM, etc. I do wonder about oils, though: does the oil go with the molded form, or stay on the mold? Does it need to be washed off, or will so little be incorporated with the mold material when it is remelted that it doesn't matter?

Washing does not seem to be a problem, as the material is literally like rubber.

POP: I am going to try that along with some concrete. Small, of course, as large mistakes tend to fill up the garbage can.... :-)

I can't really tell you about volume, as I THINK I did a fraction of the full-size recipe (like a fourth), but there was still quite a bit there. I am guessing that the one-third sized recipe would produce about 8 cups (half-gallon) of material.

I mentioned dedication of the pot & tools. It WILL scrape off, but it's not easy. (I'm nothing if not lazy!) None of the materials are toxic EXCEPT the alcohol, but I find it's just easier to shop for a large pot(s) with lids & big spoons at the thrift shop. Then, when you're finished with the mold & intend to melt it the next time you use it, you can just fold/cut it up into chunks that fit into the pot & put it away. I would use a pot with a lid for that reason.

Actually, 1 oz. = 2 Tablespoons. I don't know what I was thinking. That would make the amount of Denatured Alcohol TWO TEASPOONS. Sorry about that.

This is so new to me that I don't have many answers.

'Pup


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RE: Homemade Reusable Mold Material

I am curious to know what this could/will be used for. Soap making? Hypertufa? Candels? Fimo? Reverse rubber stamps? Candy making? Ice cube trays? Jello molds? Please post any triumphs or failures!!!
Julie


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RE: Homemade Reusable Mold Material

I really haven't used it too much, just for some leaves, but it flattened them out more than I wanted.

This is one of those try-it-&-see-how-it-works recipes.

'Pup


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RE: Homemade Reusable Mold Material

What an informative post!! I can't wait to try this! Does it retain the detail of the original when you make the mold? I have a wee internet business where I sell a sculpted product, and the commercial mold-making goo is VERY expensive -- costs me over $70 just to make one mold,(and if I don't mix it just perfectly, they are spoiled, along with the original master sculpture) -- we have around 200+ molds now, and often when I think of adding a new item, the thought of that expensive process, and the chance of failure, makes me talk myself out of it..

Woo hoo! Hope this works! I'd love to do some "just for me" things!

Pat


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RE: Homemade Reusable Mold Material

The detail is good. My material had a few small bubbles in it, but I didn't follow directions, either. I am wondering if the heat had something to do with the bubbles. The original instructions said to use a double boiler, or a smaller pot inside a larger pot that has marbles & water in it (a makeshift double boiler). I used the lowest setting on my electric stove. There is the possibility it was too hot.

Try it -- it's pretty tuff stuff!

Pat, what kind of stuff do you make? (Just nosy...)

'Pup


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RE: Homemade Reusable Mold Material

Bubbles, I don't know how this would apply to your material but I made beautiful porcelain copies of leaves by adding a few drops of detergent to the slip I painted the leaves with. My thought was that all plants have some oil in them and could cause the slip to not adhear. It worked beautifully.
Ceramic material suppliers have 'mold soap'. I'm sure its' old Castile soap. (I'm so ancient that I know what that was as a child.) You could thin the soap with water and paint on the leaf or dip it. Maybe Dove bar soap would work. Marguerite


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RE: Homemade Reusable Mold Material

'Pup, in answer to your question, and without being commercial about it, I make Doggoyles : statues of dogs posed as gargoyles, in 110 AKC breeds.

Pat


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RE: Homemade Reusable Mold Material

Some people at GW are using Murphy's Oil Soap as a release agent.

'Pup


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RE: Homemade Reusable Mold Material

The bubble problem my possibly be remedied simply through agitation. When you stir your mold mixture you are essentially cutting air into the batter. You are also capturing air as you work the material onto the mold negative or the object which is being copied. I do not know how it would work for your molding material, but when modern-day sheet-glass is made, it has to be consciously agitated as it cools to work out all the air. The same process is also used when preparing ice blocks for ice sculptures.


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RE: Homemade Reusable Mold Material

This is so interesting. Thanks for posting it. Do you recall the website that had the original instructions? I'm interested knowing when and how much of the glucose to add. Thanks. I'd like to try it with concrete.


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RE: Homemade Reusable Mold Material

I agree, this is very interesting. I would like to know the original web site also. Concrete is my thought also.


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RE: Homemade Reusable Mold Material

will this work with tufa I wonder?
anybody do this yet?
I think I found the web site needed
http://www.make-stuff.com/formulas/flexmold.html

This is new mold material is much superior to ordinary gelatin (mold glue) and is very easily made. It does not shrink or dry out like ordinary casting gelatins. If made according to directions it will retain all its original qualities indefinitely, and can be remelted when necessary.
FORMULA:

Flake Gelatin . . . . . . . 4 1/2 pounds
Water . . . . . . . . . . . . 4 1/2 pints
Glycerin . . . . . .. . . . . 9 pounds
Glucose . . . . . . . . . . .1 pound
Denatured Alcohol . . 1 ounce

PROCESS: Place the gelatin in a large container and pour the water over same; then cover container with damp cloth to prevent evaporation. Mix up thoroughly with the hands every ten minutes to keep water evenly distributed, otherwise the bottom will absorb too much water and the top portion will dry out and harden. Replace cloth after each mixing. After gelatin is thoroughly softened, squeeze out all surplus water (if any), and place in double boiler and melt. A few minutes after it begins to melt start stirring and keep stirring until the gelatin is all melted and free from lumps. Then add the glycerin (which should have previously been heated) and stir until blended. Continue to stir until all ingredients are thoroughly incorporated and remove from fire. Now add the alcohol and stir until thoroughly blended with the rest of the mixture. The compound is now ready for use. Do not add water when remelting.

A double boiler can easily be made by using two metal buckets or pans, one larger than the other. Put a few stones in the bottom of the larger container and partly fill with water. Then put mold compound into smaller container and place it in large container. There should be enough water in large container to come up at least half way on outside of small container. The stones are to prevent the small container from touching the bottom and thereby burning the mixture. Leave unused material in container in which it was melted.

HOW TO GET THE ABOVE COMPOUND TO MAKE MOLDS: First select the article you desire to duplicate. Almost all articles can be duplicated, such as celluloid novelties, metal toys, dolls, etc. Articles cast in compositions, book-ends, emblems, etc.

If the article to be cast is very simple, with one entire side flat like a book-end, emblem, or plaque, it is only necessary to lay it on some flat, smooth surface, like glass or marble, face up. Place a frame of wood or metal bars around it, having oiled the object and other parts well; then pour the pliable mold composition over it. However, for more complicated things such as door stops and novelties in forms of dogs, cats, dolls, etc., you will have to make a mold in two pieces.

To make two piece molds, plaster should be used to reinforce the mold. To make good molds you must bear in mind that both this compound and rubber gives under the weight of the casting material. Therefore, some means must be used to hold molds made from these materials in shape. It must be made so that the mold can easily be removed from the reinforcing shell so that the mold may then be removed from the casting without damaging it.

After you have applied the molding composition or last coat of rubber and compound starts to set - spread about 1/2 inch thickness of plaster mortar over it with a trowel, let set and then remove it. For full body molds in two parts - make one half, let it stand until set, cut notches in the plaster shell around the edge that will be spliced to the other half and then apply rubber and plaster to the other half. To prevent the plaster sticking, coat the splice edge of the first half with two coats of ordinary rubber cement.


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