: I am a high school technology teacher with students building a small car.
: They plan to use fiberglass to form the body shell. I need infomation on
: building a plug to form the mold. I plan to build the plug from wood
: strips as if we were building a kayak. Have I lost my mind?!!!

HI, I use to do some of this type work at Fisher Body and other places, all before CAD-CAMs. The base construction was somewhat similar to Kayak building except it was much more solid. The work was done on very large and very accurate surface plates using height guages as the main measuring tool with tolerances +/- .001. We used mahogany glued up in thin layers usually running across the whole pattern, on say a quater panel. But large pieces were built around a solid frame to eliminate weight. Later we used a special wood that was prelaminated in 1/16 inch layers to help eliminate expansion or shrinkage, and finally a plastic called Ren Shape that was worked and machined like wood. But I think strip building a pattern plug would work OK as long as you aren't too worried about accracy. You might want to contact a pattern supplier, like Ren Plastics or Meyer for some supplies and idea papers. I have seen Meyer on the net but not Ren. One thing I would definitly get is parting paint. It is water soluble and use to be green. I have seen it save many pattern from destruction from sticking. We shellac the wood first until shiny. Then put on the green parting by brush or spray and let dry between coats. Then brushed on three coats of Tree Wax and shine each coat and finally put on a mold spray parting. Then we brushed on a (Surface Coat) of epoxy and after the brushing we poured the rest of the mix over it in a thin layer. Don't let the excess flow into pockets or it will have excessive heat and bubble or warp. Right away we dipped our brush in alchol and flipped it on the surface coat, which brings up the bubbles to the surface. Then let it set up to the point where you could dent it with you fingernail (this makes the coats adhear better at this stage while most of the heat has dissipated) and pour on a second (Surface Coat). Again, when you can dent the epoxy with your fingernail, put on a coat of (Laminating Coat mix) epoxy and start laying your cloth and brushing in laminating mix into each layer. Hope this helps in some way.

John