Thread: Fiberglass molds: Suggestions?

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I'm considering making a fiberglass hood scoop for a buddy.

What material would you recommend for making a mold?

I heard of carving one out of foam or making one out of paper mache covering it with bondo and sanding it smooth.

Any other suggestions?

What about a release agent?

Thanks!

I've built protoypes out of urethane foam insulation board. Peel the foil off, and glue them together, then finish shaping with a sanding board.

After that, I glass over the top with enough layers to give me an eighth inch minimum, and finish the scoop with bodyfiller and 2K primer. When you are done, scrape the foam off the bottom, and sand a little to smooth the underside.

www.tapplastics.com has everything you need, and how to section to help you get started

If you have to ask I would suggest just take the hour or so drive down from Waukesha to Addison or Naperville, Il and buy one from VHT or Glastec---If you want something different then modify it

Another little tip, if you decide to start from scratch.

This is a little harder than using urethane foam board.

I have built forms out of "hardware cloth"...which is just a large, very heavy, bendable screen. This method isn't really as good for rounded shapes. You can take some needlenose pliers and wire to attach pieces together. Make the form, and set it up so it's very stable, then lay saturated fiberglass cloth over it, and roll or brush until it conforms to the shape. If you have catalyzed the 'glass the right amount, you will have 30 minutes or more to work it.

Build up 4-6 layers, then skim coat with filler. It will really bond to the glass, if you put it on right after the glass "kicks".

what type of scoop do you want to build?? A blower scoop, tunnel ram scoop, or just a raised panel of a couple of inches???

For the floor board of my wifes 33 3 window , I laid a thick rubber packing sponge like substance out of a super charger packing box over the trans whick gave about 1 1/2 inches of clearance, wrapped with wax freezer paper and laid down some glass cloth--

http://i12.photobucket.com/albums/a2...sssections.jpg

I just covered some cross sections with chicken wire on a 1X2 frame that was attached to 2X4s. To that I allpied about three layers of glas amd filled with gelcoat for a mold.
Side pieces used braked aluminum for a mold.
Nose cone mold was chicken wire/foam urethane insulation with fiberglass applied for a mold.

Silicone spray lube worked for release lube for me, buy any handling will mess up later painting. Even the lightest of silicone from your hands will contaminate.

Check with any fiberglass supply house. They should have a spray mold release. The one I used was green, and water based, so cleanup is easy.

I'm not making anything intricate. just a half moon shape for an old plastic kit car

Thanks for the ideas!