foam insulation
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 802
Likes: 0
From: Bueche Louisiana
foam insulation
have a question regarding the wheelwell insulating process
has anyone thought of sealing up the bottom of the wheelwell cavity and spraying foaming insulation (great stuff name brand) in the cavity instead of doing the fiberglass batting as everyone else has done
thoughts or comments???
has anyone thought of sealing up the bottom of the wheelwell cavity and spraying foaming insulation (great stuff name brand) in the cavity instead of doing the fiberglass batting as everyone else has done
thoughts or comments???
Melting Slicks
Joined: Jun 2004
Posts: 3,439
Likes: 6
From: Newark, DE
St. Jude Donor '06
I think this would be a mistake. The spray-in foam dries rigid. In its intended purpose, the building industry, rigidity is a good thing. There could be undersireable side effects if you make the area behind a composite body panel rigid (e.g., cracking versus flexing, in the case of a low speed collision). Also, I see from your profile that you have a C5 coupe. I believe that the front edge of the rain gutter on the rear hatch drains into or adjacent to the cavity in question (maybe someone who has performed the fiberglass batting mod can comment). You would be in a world of hurt if you plugged that up!
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 802
Likes: 0
From: Bueche Louisiana
thanks
thats what i wanted to see any possible cons of using the spray stuff
just thought of it didnt sit down to really think it out 2 very good points that will be consiered
although they do have the spray foam that doesnt dry rigid and a well placed piece of pipe just below the drain for the hatch would probably work but seems like it would be more trouble to build than its worth
i was considering the spray foam as an alternative because of the weight savings in comparison to the fibergass batting (and itching)
i havent had the time to pull the wheels and inner well out to look at whats actually back there
thanks
just thought of it didnt sit down to really think it out 2 very good points that will be consiered
although they do have the spray foam that doesnt dry rigid and a well placed piece of pipe just below the drain for the hatch would probably work but seems like it would be more trouble to build than its worth
i was considering the spray foam as an alternative because of the weight savings in comparison to the fibergass batting (and itching)
i havent had the time to pull the wheels and inner well out to look at whats actually back there
thanks
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If you ever had to body repairs in the area after you installed that stuff the body shop would either turn you down or charge you MAJOR $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$ to take it out! 
I would not do it. Install something that is easily reversable if necessary!
Evil Twin is the MAN to talk to about this topic! He has all the info and facts!
Bill C
I would not do it. Install something that is easily reversable if necessary!Evil Twin is the MAN to talk to about this topic! He has all the info and facts!
Bill C
Melting Slicks
Joined: Sep 2003
Posts: 2,669
Likes: 5
From: Florida Gulf Coast
St. Jude Donor '05-'06-'10-'11
Foam is a terrible idea for lots of different reasons. One of which is that it expands so greatly that you could even crack a body panel if it got into an area where it could not expand back out of fast enough.
The batting used for the insulation mod in question is just to break up sound waves. It is cheap and works well for this purpose.
ET has taken all the guess work out of this project. I am going to be doing this mod myself soon and I will use the FK and reflectix material.
The batting used for the insulation mod in question is just to break up sound waves. It is cheap and works well for this purpose.
ET has taken all the guess work out of this project. I am going to be doing this mod myself soon and I will use the FK and reflectix material.
Safety Car
Joined: Nov 2003
Posts: 4,979
Likes: 5
From: San Diego, CA "leaf" "tee" "e"
I'll repeat some stuff that I've had experience with:
1. It'll expand with a lot of force
2. Super sticky. Wear gloves, and don't get it on anything you don't want it on. It'll stay stuck to your hands for weeks, and you'll probably never get it off paint.
Other thing I didn't see is that the foam like Great Stuff, or anything at home improvement stores, isn't made for closed cavities. This stuff won't dry out if it can't get to air, so part of it may stay a big 'ol tub of super sticky jelly waiting to create a nightmare. There are anarobic (??) foams that are specially made for filling automotive enclosed body cavities that will fully cure without air. This is the only thing to use if you must go with foam. I'm pretty sure you can only order it in a bucket. With all the time it would take to find, pick and order from a supplier, do the same with a spray gun kit, and figure out how to use the kit, you could install fiberglass batting in your Vette, plus several more.
1. It'll expand with a lot of force
2. Super sticky. Wear gloves, and don't get it on anything you don't want it on. It'll stay stuck to your hands for weeks, and you'll probably never get it off paint.
Other thing I didn't see is that the foam like Great Stuff, or anything at home improvement stores, isn't made for closed cavities. This stuff won't dry out if it can't get to air, so part of it may stay a big 'ol tub of super sticky jelly waiting to create a nightmare. There are anarobic (??) foams that are specially made for filling automotive enclosed body cavities that will fully cure without air. This is the only thing to use if you must go with foam. I'm pretty sure you can only order it in a bucket. With all the time it would take to find, pick and order from a supplier, do the same with a spray gun kit, and figure out how to use the kit, you could install fiberglass batting in your Vette, plus several more.
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Safety Car
Joined: Mar 2002
Posts: 3,556
Likes: 2
Check out my web page for what the rear wheel wells look like. There is very little room back/up there. Click on photo for bigger size and fascinating commentary 
http://home.bellsouth.net/p/s/commun...iew=thumbs&ck=
http://home.bellsouth.net/p/s/commun...iew=thumbs&ck=
Le Mans Master
Joined: Sep 2004
Posts: 5,707
Likes: 4
From: Los Angeles
The number one reason not to use foam is:
Thermal insulation is NOT necessarilly the same as acoustical insulation.
The desired results will not be achieved. For reasons far too complex to go into here, the stiff, lightweight hardening foam will probably not be a very good acoustical absorbing material.
Thermal insulation is NOT necessarilly the same as acoustical insulation.
The desired results will not be achieved. For reasons far too complex to go into here, the stiff, lightweight hardening foam will probably not be a very good acoustical absorbing material.
Last edited by robvuk; Dec 2, 2004 at 09:47 AM.
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
The desired results will not be achieved. For reasons far too complex to go into here, the stiff, lightweight hardening foam will probably not be a very good acoustical absorbing material.
no dampening properties.FYI; there are three types of that "construction foam". One has no expansion properties. The three types can be differentiated by the can colors.