Cavalier Mustang

[airdave]

yes, I said "Rich has blown a plastic canopy that..."

so...he made it.

[richkat]

Yep I made it.....I build the paper canopy "in side out" that is glue tabs on the outside. Use paper to extend the bottom a bit then paint the inside to water proof and fill with plaster. Once dry sand and clean up a bit and you have a mold to vacuform a plastic one.
.........Rich

[Isaac]

Originally Posted by richkat

Yep I made it.....I build the paper canopy "in side out" that is glue tabs on the outside. Use paper to extend the bottom a bit then paint the inside to water proof and fill with plaster. Once dry sand and clean up a bit and you have a mold to vacuform a plastic one.
Attachment 224755 .........Rich

Rich


What material is the plug made of?


Thanks

Isaac

[richkat]

Durham's Rock Hard Water Putty.....no kidding, it's a plaster of Paris type of putty but much harder. Sets fast and is sandable, I use Bondo filler for pin holes and a smooth finish. Any bad spots will show in the finished canopy. Here is a pic of my vacuform box, just a simple box with peg-board and soft foam seal around edge. The plastic holder is two layers of 1/4" wood with small bolts and wing-nuts. I heat the plastic till soft over a burner (electric) on the stove then slap it on and turn on the vacuum to suck it down. The vacuum hose fits in the hole in the end of the box. Also a pic of the mold I used for the Cavalier Mustang (notice the hump at back). I get plastic from all kinds of packaging but you can buy sheet from hobby stores........Rich

[elliott]

I would have thought that the plastic would cool and stiffen before you are able to tighten down all the wingnuts. Is a light spin of the wingnuts sufficient to seal the vacuum or do you have to crank them down?

[richkat]

The plastic is held between the two layers of the frame then heated, it is cut out (little U shaped cuts) to clear the bolts and clamped tight between the the layers. Then heated till it sags a bit (you have to test just how hot) over the burner then the frame is slapped on the box with the vacuum already on. You can reheat and it will flatten back out and try once more. Sometimes it won't suck down good around the bottom and you have to put the plug up on a block to raise it a bit to help suck in around the bottom....Rich

[richkat]

Here are a couple of pics of the frame....Rich

[elliott]

Makes perfect sense now. All it took was a gentle nudge in the right direction. Thanks Rich!

[RyanShort1]

That's what I was looking for! Thanks for the reply!

Ryan

[airdave]

Rich, I am going to build the exact same box.
There have been many good designs on here.
And I already tried building a small one.
But I like how yours is built.
I will give it a try.

But first I will go hunting...again...for Durhams.
I don't think we have it here.