: I will put this idea out for those that might want to use this proven and
: cheap technic for taking casts off of large models (boats maybe)that was
: used at Fisher Body many years ago. We would take casts off of wooden car
: model sections such as a station wagon car top. Lets think of this as
: taking a cast off a kayak boat haul. A flange would be built up around the
: shear seam sticking out a couple of inches or so usually held in place
: with clay. Then we sealed the model with green water soluble parting and
: put several coats of wax and a light coat of crisco on. With a large
: bucket of mixed USG Hydrocal (Green plaster, like cement and doesn't
: shrink of expand)a very liberal coat of this is put over the serface and
: an air vibrator is held against the model to vibrate out the bubbles. Then
: after this set just a little to stiffen some, another layer of hydrocal is
: put on and then bailed hemp,(like straw) is dipped in the Hydrocal and
: padded onto the model. This makes a very strong mold. If you can turn the
: boat and mold over you can make the matching deck half mold. Put alighment
: pins into the hull flange or drill large holes for alighments. You now
: have two mold halves to fiberglass a boat from. Of course there is a lot
: more to this and technique also but this is a starting point if you are
: ever serious.

hi john
what did they use the casts for after that- more prototypes to modify? what did they make the new takeoffs from? f/g? more plaster?

and how did they deal w/ undercuts? like on the station wagon roof the inset windows - how would you lift the cast off? several cast parts or other inserts?
-mick