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spray foam?

Printed From: the12volt.com
Forum Name: Fiberglass, Fabrication, and Interiors
Forum Discription: Fiberglass Kick Panels, Subwoofer Enclosures, Plexiglas, Fabrics, Materials, Finishes, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=76403
Printed Date: March 29, 2024 at 3:55 AM


Topic: spray foam?

Posted By: nicholas moffet
Subject: spray foam?
Date Posted: April 18, 2006 at 2:06 AM

will the spray foam you buy at home depot make good molding foam? I want to take a mold of the top of my car to make a spoiler. will this work?



Replies:

Posted By: mi_what
Date Posted: April 18, 2006 at 8:46 AM
Are you talking about the insulating foam? I personally don't see why not, the only thing that I can see getting in the way of that is air bubbles; that foam only sprays lines and I've noticed that the lines don't always attach to each other fully. There's always some gaps in between. Try to find the expanding foam that you can mix together and just pour. If you can find it, there is a website out there that features the door panel build (same concept) from a civic Si that the alpine crew threw together. Try to find the link to that and it will give you and idea of how you should build your rear spoiler.




Posted By: bellsracer
Date Posted: April 18, 2006 at 1:41 PM

We use expanding foam all the time for body mods and interior work, We recommend using the window/door expanding foam from Great Stuf. Just make sure you cover it with aluminum foil (light duty) before you start fiberglassing over it. That way the F/G will not eat the foam away and you can leave the foam in. If you want to reinforce it (for more inttricate designs, lay 22 guage chicken wire (the square kind, not the hexagon type; the hexagon's twists cause issues) over the foil to give the F/G some serious strength for more unique designs.

Ganbatte ne! (Good Luck / Do your Best)



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Never send your ducks to eagle school.
The difference between ordinary and extraordinary is that little extra.
The 3Ls of life: Learn from the Past, Live for the Present, Look to the Future.




Posted By: crazyoldcougar
Date Posted: April 18, 2006 at 8:07 PM

i have found that the great stuff brand is excellent...however, i have had great sucess not covering the foam with anything..the resin (polyester) doesnt really seem to eat it at all. to each his own though..

another thing too, if you dont spray enough/ fast enough you will end up with the line effect, however after you sand her down to the approximate shape you want and there is still lines, you can apply sheetrock over it to fill the gaps, and it sands super easy too..then you can apply fiberglass directly to it..applying tinfoil will allow you to release the mold from the fiberglass.



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Fiberglass Guru.




Posted By: torquehead
Date Posted: April 18, 2006 at 11:25 PM

Yes, the cheap easy from the can spray insulating foam works good.

Both points from Bells and Crazy.  I like the idea of being able to make some components in separate peices.  Such as your spoiler, I have made them one piece and 3 piece.  The 3 piece obviously my favorite, being I can keep separate molds for future prospective jobs.  It also allows you to make the top section of the spoiler in different designs allowing interchangability and ease of mounting.  Or, when one of the posts may get damaged, just duplicate the other side and recreate it for a replacement.  If your a crafty sport and have time, you can make a shallow mold of the posts mounting surface.  In the mold, open a tube of RTV silicone and top the mold off with it, scrape the exposed surface flush with something smooth/straight like a ruler and let the silicone dry.  After the silicone is cured, you have a soft rubber mounting pad to place under the spoiler posts to pretect the surface of the trunk when the spoiler is mounted.  Dont make the molding or the silicone too deep, you only need about an 1/8 of an inch.

I hope you meant you wanted to make a mold of the top of your trunk or rear quarters???  I have actually seen a spoiler on the roof of a car before and....!!!!!   ....I have nothing else to say about that.






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