Bubble Tops?!

[JMD904]

I had a wild idea of making a bubble top custom on a '57 Bel Air. Anyways, how could I scratchbuild a bubble top? I'm wondering if a vac-u-form or a custom mold would be better.

[Casey]

I would say make a buck then vac-form the "glass".

[JMD904]

OK. Just gotta find a company that does it locally. I know that equipment ain't cheap! I thought over the mold. Seam lines would be a issue.

[Art Anderson]

OK. Just gotta find a company that does it locally. I know that equipment ain't cheap! I thought over the mold. Seam lines would be a issue.

Actually, if you do some searching on the web, you ought to be able to find a how-to article someplace (been done almost to death in model magazines over the past 40-some years--trust me on this one!) on how to build your own vacuum former for practically peanuts! Basically, what you would build is a simple wooden box, using perforated circuit board stock from Radio Shack, and set up the 'box to hook up to a shop vac, or similar powerful vacuum cleaner.

Every "bubble top" I've ever seen, magazine and in person at a car show. was built using a vacuum-formed plexiglas bubble canopy--same principle, same methods as fighter plane canopies have been made since the introduction of the P-51D in early 1944 for the war in Europe. Only differences will be in the shapes, and the materials--plexiglas is much too thick for a scale model car. However, with some looking around (if you live near a large city, walk through the Yellow Pages to find an industrial plastics supply house there--they should have all manner of thin clear plastic, most likely PET-G, which is the clear plastic that soda bottles, and bottles for drinking water are made from--that stuff vacforms BEAUTIFULLY.

Of course, you will have to carve, shape and finish off a "buck" or form for your bubble top, but that isn't rocket science either--in fact none of this process will be--but there is a bit of a "learning curve". I, along with numerous other builders here have vacformed many pieces of clear plastic for model car projects--lots of help available right here in these forums.

Art

[scampy72]

search on instructables.com for a vacuumm former, i think ive seen a couple.

[Mike Kucaba]

I'd concentrate on building/carving /shaping the form first. It's going to have to be razor smooth so it forms like glass. You might be able to make a reverse mold,by using the form upside down and pushing it thru a piece of heated clear plastic thru a hole cut in some hardboard the shape of the bubble. Have you looked at bubble tops from other cars?

[LDO]

Art mentioned using perf-board from Radio Shack. That would be you platform. They also sell "project boxes" that make up the rest of the vacuum former. I made a 6x9 vacuum former like this last year. You'll need to find a way to get you vacuum cleaner hose to make a tight fit to the box I used several plumbing fittings and wrapped a little masking tape around the end of the hose.

Here's an idea for your bubble top: get the top of the car the way you want it

(If you'll be making any changes for the base of the bubble) then cover the area with Bare Metal Foil. Use Milliput Superfine White epoxy putty over the BMF to form the base (or all) of the buck. The BMF acts as a mold release, allowing you to pop the buck right off of your car. When vacuum forming, raise the buck off the platform so the vac-formed part curls under it just a bit. When you cut it off the buck, you'll be very close to a good fit to the car.