Thursday, August 25, 2011

My fantastic learning experience making the fiberglass Mongoose

Six months from drawing to driving.
(Conceived, designed and built in 1964)


Mongoose Model

I had an extraordinary learning experience designing, building and racing my own competition fiberglass sports car.  I made the drawing first, then I made the clay model about 18" long so I could visualize how the finished car would look. I knew that visualization was a much needed requirement in creating art and photography, but it was absolutely essential in building of the Mongoose. Also while deciding the placement of all the bulkheads in the mold.

The Mongoose's original design changed many times though out the project out of necessity. A 2,000 pound male plaster body had to first be formed out of wooden lath on wood bulk-heads, with some chicken wire all mounted on a 2" x 4" frame built on two scrap Ford solid rear axles gotten from a bone yard. The plaster male-mold was painted and finely finished, looking just like a real car. Then it was heavily waxed many times as a releasing agent for the fiberglass female mold from the male plaster mold.

Wooden Mold Frame


About the same time I started with a Red '63 stingray convertible that had been rolled over on it's top not hurting anything but the windshield and the cosmetics of the body. The wrecked Corvette Stingray body was taken off the frame, the seats and good parts sold. That left the Corvette frame bare with the engine-transmission plus the 4 wheel independent suspension, all of which were destined for some major modifications. The 327 cubic inch small block Chevy engine was built full race by a local expert race engine builder.The engine was completely race ready, better than new with a dependable strong output of 450 bhp. The frame was shortened in length from the original 110' wheelbase down to 89". Lightweight chrome molly tube cross-members were welded in the frame by a government certified welder.  The welder also made the engine and transmission mounts, even the custom race trailer that carried the Mongoose. The center of gravity was lowered by heating the springs. That also lowered the roll centers of the suspension, not necessarily a good thing. The car strangely spun-in off the corners, instead of spinning-out............a lesson learned a little late.

While that was going on the female fiberglass mold had to be laid up over the original plaster car with three different types of fiberglass layers. First, a fine weave for the smooth finish, then a spun cloth mat layer for volume and finally a layer of real coarse weaved fiberglass cloth for strength.

Mongoose Plaster mold finished and ready to lay-up fiberglass

The pieces of fiberglass cloth had to be cut out approximately before hand to get them all ready for the big lay up.
There's a major difference between a hand lain fiberglass body and a commercially (chopper gun) blown one. The fiberglass bodies like the mass produced Corvette. A blown body must be much thicker and therefore weigh much more, to have the same strength as the much lighter Hand-Lain body.

When you lay up fiberglass you need a good reliable helper, someone you can really depend on. You only have 45 minutes to do your job before the fiberglass sets up and everybody working gets stuck together including their finger tips, with strings of hardened fiberglass. You had better pick your helper well and have total confidence in them that they'll get the job with-in the alloted time, also be someone that you don't mind being stuck together with. I picked my father (RIP), as we were buddies, I knew from past experience that I could depend on him. When we did end up stuck together, I knew it would be after successfully laying up the female fiberglass mold. You might say it was a family bonding experience. LOL.

I had to call on my father to do the same thing again in only a week for the final fiberglass Mongoose body. The female fiberglass mold with all it's supports took that long to cure. My father knew very little about cars and nothing at all about working with fiberglass, but he was dedicated to helping his son. So my father and I had to do it twice, once for the female fiberglass mold, once again for the final male fiberglass Mongoose body! .................................and we ended up stuck together both times.

Mongoose in the Ruff

The Ruff Mongoose when first on the frame

The final fiberglass body looks pretty ruff at first.

Carol II & first edition Mongoose I _ Charcoal

Through a lot of work fitting parts together plus some paint and wax, 
the finished product looked somewhat better.

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