How-To Information for GM Foam

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How-To Information for GM Foam

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GUIDELINES FOR USING GM FOAM

MOLD PREPARATION FOR ULTRACAL 30 AND OTHER STONES

1. New damp molds should be sealed with wax before applying GM Foam Mold Release. Failure to do so usually results in pocked surfaces on the finished foam, and loose skin. An effective wax sealer can be made by thinning Johnson’s Paste Wax (or any other commercial carnauba type paste wax) with 99% alcohol. A good formula for this “alco-wax” is 1 part wax to 5 parts 99% alcohol. This thin wax sealer is painted into the mold, then dried. It is also useful to bake the empty waxed molds at 150_ F for 1-6 hours. Thick molds can take many hours to dry properly. A second coat of wax sealer can now be applied, dried, and brushed out with a dry brush. A sheen usually develops on the mold surface.

2. On the sealed, buffed mold surfaces, paint a thin layer of GM Mold Release and allow to dry. Whisk any excess dried release away with a dry brush. Molds are now ready to be used.

FOAM TIPS

1. Please READ THE INSTRUCTIONS prior to starting your foam job.
2. Don’t be a slave to the schedule. All mixers run differently, and many environmental conditions can affect how the foam will rise in the mixer. If you understand how foam latex works, you will be able to adapt to any situation. Call GM Foam’s technical staff if you need help with your schedule.
3. IF YOUR FOAM GELS TOO FAST, cut your refining time by a minute or two. This means you will be pouring your Gelling Agent a minute or two sooner. In extreme cases of heat and humidity, you may need to cut down the time and use less Gelling Agent. You can use as little as 10 or 12 gms Gelling Agent per 150 gms Latex Base.
4. IF YOUR FOAM GELS TOO SLOWLY, add a minute or more to your refining time. In extreme cases of coldness and low humidity, you may need to add minutes to your refining time, and also add more Gelling Agent, up to 20 gms Gelling Agent per 150 gms Latex Base.
5. Foam that is open to the air ( blobs on the table ) does not accurately reflect the level of gelation inside the mold. Foam inside a closed mold can take up to 10 minutes longer to completely gel.
6. SLUGGISH OR UNDERCURED FOAM can be remedied by curing for a longer time. If your oven is tightly packed with molds, you will need to allow extra time for heating, and you’ll need to leave enough space between molds to allow even heating. OVERCURED FOAM loses tear strength and stretch. Cure for less time in such cases.
7. PIGMENTATION is best achieved by using GM Foam Water Base Pigments. These are specially formulated to be colorfast in the foam, and will not cause tackiness in the foam the way other tints will. Remember to add pigment at the beginning of your run, after weighing your base and components.

DEMOLDING

1. Demolding is easiest when the molds have cooled to 120-130_ F. This is warm to the touch. You can demold at higher temperatures, but it is hard on the molds, and causes cracking. It helps to have a thin wooden stick to insert between the mold halves as they are opening. This wooden stick can be used to carefully pull the foam away from one side of the mold, leaving it intact on the other side. The foam is then powdered with talc and removed from the second half of the mold.

2. IT IS VERY IMPORTANT TO WASH FOAM PIECES. They should be placed in a container of warm water with a few drops of liquid dish washing soap or baby shampoo added. DO NOT USE TOO MUCH SOAP. Gently squeeze the water into and through the pieces. Rinse in clear water until no trace of soap or residue is left. Press the water out of the pieces on cloth or paper towels. Do not wring. Dry pieces flat, or on forms that match their natural curvature, so wrinkles won’t set in. IT IS IMPERATIVE TO DRY THE PIECES BEFORE STORING. Wet pieces stored in airtight baggies will develop a sulfur smell.

3. When molds are used repeatedly, a brown residue builds up on the mold surfaces. This buildup can be scrubbed out with 99% alcohol and a short bristled brush. Only use enough pressure to lift the residue; excessive scrubbing can remove precious mold detail.

STORAGE OF PIECES

When foam pieces have been washed, dried, and powdered, they are best stored resting in their natural curvature in airtight containers away from light. It is convenient to use either zip-lock plastic bags, or plastic refrigerator containers that have airtight lids. These baggies or or plastic containers are then stored in a cardboard box or any other opaque container that can keep out the light. If stored in this way, pieces can be stored for years without any deterioration. If a foam piece is stored or left to air out with a crease or fold in it, the piece may take a set with a permanent crease line or indentation. Store pieces in their natural curvature.

SAFETY INFORMATION

1. Read the instructions before starting. Refer to the material safety data sheet (MSDS) for more information.

2. Have adequate ventilation to remove ammonia fumes.

3. Wear safety goggles and gloves when working with foam.

4. Do not let foam components come into contact with skin. If this accidentally happens, wash with soap and water as soon as possible. Clean up spills.

5. Wash your hands after working with foam. Never eat, drink, or smoke without washing first.

6. Anyone using foam latex should keep a set of material safety data sheets nearby in case of emergency.

7. Be sure to mail in your MSDS request card to obtain a set for yourself.

WARNING: Never use a household oven for curing foam.
Fumes given off by curing foam are toxic for food use.
Keep these & all chemicals out of reach of children & pets.

THE GM FOAM INSTRUCTIONAL VIDEO IS AVAILABLE FOR THOSE WHO WANT TO LEARN MORE ABOUT HOW FOAM LATEX WORKS.

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