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How can I make CHEAP homemade reuseable hard clay for mold making? Answered

Looking to make fiber glass parts for my car. I want to stick something to the body and mold it. Then cover it with sr-an-rap and cover with fiber glass.



7 years ago

I work here part time, making clay. One of the clays we produce, M-340, is very popular with taxidermists because it is cheap, easy to work with, very smooth, and has very, very low shrinkage. They use it to "flesh out" foam forms that they then cover with the hide or skin, so it might be useful for you application. Call on Friday, and I'll help you out.

This may not be quite what you are looking for... but I have seen body parts (fender wells) molded by simply taping corrugated cardboard cut to shape to the original thoroughly-cleaned body, then adding lots of bondo to cover the cardboard, and shaping the bondo by hand/file/sandpaper to the desired shape. A lot of feathering was needed to give a large area for the new fender well to bond to the fender, but it worked. I would want to top off the bondo with a layer of glass-and-epoxy for strength, though.

Good luck!

Yeah I'm needing a soft to hard clay like substance. Not bits and pieces of things.

PVA glue - Brown paper strips. - Make sure you grease or oil the body work so you can get the mould off.

the initial layers need to be as smooth as possible I have used news paper in the past as this moulds well when wet - No glue - Make sure you minimise or avoid wrinkles.

Mould ridges into the surface with your fingers once you have a smooth layer to give the mould rigidity.

A GOOD coat of mould release to ensure GRP will not stick to mould.

Alternative make a GRP mould. Again LOTS of mould release or grease on the body work to prevent sticking.

Mmm, wax-impregnated cloth? Soak an old t-shirt in candle wax, warm in the oven, lay on the car and repeat as necessary.