Chapter 11 - Miscellaneous Notes
This chapter just contains miscellaneous notes about different things.· These are just thoughts and tidbits that I have picked up here and there and are in no specific order or reasoning.· Some of these notes may be moved to a different section of the book at a later time.· Think of it as more of a scratch pad for the thought process.
Tips for using silicone caulking for making a mold
- Use a brush to spread the silicone in very thin layers on the model. This will force out any small air pockets that may be trapped in it.
- When making coats of silicone, latex or whatever, brush each coat in a different direction than the last. This will create a stronger mold from different grain directions.
- Continue this process until the silicone is built up enough to be somewhat rigid, say a quarter of an inch. fill the rest of the form with a hard setting backing. Resin, liquid fiber glass, plaster, etc.
- Repeat the process with the other side of the mold.
How to create a pull away mold (Slip Mold)
- Attach the item to a piece of styrene or Plexiglas.
- Paint layers of latex on the model, extending it an inch or so away from the model onto the styrene..
- Continue painting layers as described earlier until you have an eighth inch or so of latex built up.
- Pull latex from model covering it with talcum powder as you go. The talcum powder prevents the latex mold from sticking to itself.
- To cast using the pull away mold, cut a hole in a box large enough to set the mold in, but small enough for the lip of the mold to rest on the box.
- Pour and pull latex slip mold from casting.
- Vaseline thinned with Naptha (lighter fluid) can be used as a release agent on silicone. The ratios very. I have used 10:1 (Naptha:Vaseline) and applied it with a spray bottle.
- Soapy water (8 oz. water and a few drops of liquid soap) can be used as a release agent on clay for making plaster molds. Additionally, I spray it in RTV molds that I cast plaster in to help reduce the number of air bubbles seen on the surface.
Parting line fillers
- Soft wax can be used to create a mold line and can be melted away with a light bulb.
Thinning Silicone Caulk
- Sources on the Internet indicate that Distilled water, Naphtha, Toloul or charcoal lighter fluid can be used to thin silicone caulk in a tube. One suggestion was to mix 50:50 Naphtha : Silicone Caulk to about the consistency of honey and paint on. These need to be tested.