Spray Foam Dilema

[amasciarelli21]

Well getting close to paint finally but ran into a problem, about two years ago i drilled out in the inner skin of my deck lid because the inner skin wasn't attached to outer skin. I installed orange fire foam, did a great job connecting the two skins but after finding high spots in the deck lid for a second time now i've conclude this stuff is moving. I re-drilled the inner skin and have been pulling foam out for quite a while with a coat hanger but i was wondering if anyone knew of a solvent that might dissolve this stuff, i have tried testing w/ lacquer thinner and acetone and neither one works. Any thoughts?

Ang

[1932]

Gas eats up a lot of foam but will not smell good.

[mikeinatlanta]

Can you clarify what you mean by orange fire foam? It may very well be an intumescent foam specifically designed to expand when heated. It that is what you have, nothing will dissolve it without also dissolving your deck lid. You will have to take more drastic action.

EDIT: Not positive what you have, but the orange fire foams I'm seeing although not intumescent, are made from urethane and will not dissolve with any chemical that will not also damage you deck lid. It needs to be replaced with a structural foam.

[amasciarelli21]

Thanks 1932 I didn't consider gasoline but i'll try it,

Mikeinatlanta, as far as type of foam its a spray can fire block foam and yes although i use it often in construction i should of realized it is designed to expand when heated. I'll try to continue scraping out as much as i can or worst case i'll separate the inner and outer skin.

Ang

[mikeinatlanta]

If it is urethane (about 95% that it is) gasoline won't touch it and just give you more mess to clean. If you want to attempt to dissolve it, use a no residue solvent that won't leave a mess to clean. The only way I know of to clean it up is to separate the liner and sand it off.

Guys should take note of this when tempted to use insulating foams on their cars. You are much better off to buy a two part structural foam.

[amasciarelli21]

Yes i agree, i'm going to separate the panels and get it over with, i hope its the last issue so i can get to paint. A great word of advice is to stay away from the spray can foams i'm obviously learning the hard way but i've also been told that they can reactivate under heat and sometimes may revert back to there liquid form. That sounds like it would be ugly!

Thanks for the input

Ang

[mikeinatlanta]

Foam can be a really good thing if done correctly. I suggest using the 4lb density in this application. If you mix it in small batches and add in stages expansion will not be a problem as the expanding foam will always have somewhere to go. You want to let it cure about 30 minutes between batches.
http://www.uscomposites.com/foam.html

[AC Bill]

Why not first, post a "hood wanted" ad in the classifieds here, and on the FFCars forum, and see what pops up.. Might save you a lot of screwing around in the long run..

[amasciarelli21]

AC Bill, i thought of that but its not the hood its the rear deck lid and i fiqured no one would have a extra one of those. I separated the inner skin and was able to remove all of the foam. I have the inner skin fiberglassed back on but am back to original problem of having alot of flex in the deck lid because the two aren't connected.

Ang

[AC Bill]

Hmm.. there must be a way to help with that flexibility.
Everybody makes their cars different, modifying them sometimes out of necessity, or for personal preferences. What if you installed a luggage rack, or a faux spare tire cover, which connected the two panels better, and stiffened up the deck lid? It might look pretty cool too.

http://www.classicluggageracks.com/uploads/1/6/2/5/16259728/8715388_orig.jpg

http://en.academic.ru/pictures/enwiki/49/1959_Imperial_2-door_green_rear_MD.jpg

[BASmith]

Ang,

Check out Tim Whittaker's build thread. I believe he made some fiberglass "plugs" and bonded them between the two "skins" to stiffen the assembly.

Bruce

[gumbya55]

Hey Ange, I see you're still waiting on paint...I did link the inner and outer panel by cutting 3" holes from the inside, just the inner skin, then filled it with fiberglass mat and resin until it was flush. Did the same in the hood. Worked really well, no more flex. I still have to clean up the insides of the panel to make them ready for paint, but I'm pretty confident they are not going to move or change. I also added another layer of mat to the inside of the doors, cause I thought they were a bit weak too (especially tops after I cut the slot for the windows). I added angled aluminum panels on the edges, glassed those in, now the tops of the doors are solid...

Hope you get to paint soon. Did you get it registered yet?

57287

[amasciarelli21]

Thanks guys,
AC Bill, thats an interesting idea, the spare tire carrier may look cool on a full fendered car.

Bruce i was looking for Tims Link i saw a picture of his deck lid w/ the fiberglass work but didn't see what he did. I also saw he made a long cut down the sides wondering if installed steel rods.

Hey Chris, yes i,m all torn down and doing final touch-ups before paint (should be ready in 2 weeks), I Think i'll try the fiberglass plug idea that should work. I didn't do registration yet i fiqured i'll paint and reassemble then have it inspected, i can do the interior work at a latter date. How are you making out w your body work?

Ang

[gumbya55]

Yea Ange, it worked well for me. I'm still working on the body, hopefully start pulling things apart for prime in the next week or so. I think I'm going to put it back together primed (with the fenders, extra lights, wiper etc) get inspected, then pull that stuff off before paint. It's a pain, but for the car I want I don't think I can get it inspected without those things. I shooting for a fall inspection, paint over winter...

[amasciarelli21]

Sounds good Chris, who knows we may both end up at inspection the same day, that b cool.