Spray foam inside cab roof?

[swamp rat]

Originally Posted by cdowns

for noise problems i always just got bigger speakers

Huh? what??

I'd love to read about how the foams work for this in the long run.

[Mondo]

Looking at the cut away roof, I doubt you could get the foam to cover most of the roof... it would take a long tube or something to get far enough in there, even though the stuff expands.

[Zeke]

I wouldn't worry so much about the foam absorbing moisture as moisture that would be trapped between the foam and the metal. There would be no way for it to get out. If you look at the inner roof on the pictures the rust came from condensation, it will still form even with the foam just from temp change but would not be able to evaporate. As was said newer vehicles have much better corrosion protection than ours. Definitely would use stuff with corrosion inhibitors. Also you would not know if there are any air pockets that would collect moisture.

[bigsnookmaster]

I used Second Skin Damplifier Pro throughout my cab, and on the underside of the roof, then installed a headliner that was also padded. The truck is amazingly quiet, even with a 406 mechanical roller motor in it.It also has a 3" mandrel bent exhaust with an x pipe.If you have good weatherstripping,exhaust, and insulate it well inside, you should be fine. .02

[tonypaul]

I spoke with a guy that has a spray foam business today, he does Rino lining and spray foam all from a moblie trailer. He said that he has done cars before in just the manner that I have questioned. He recommended spraying the inside cavities with WD-40 or like product, and then spray the foam. He offered to mine for free if I drove to a location that he was working at but my truck is a long ways off from being able to be driven. He suggested using "Great Stuff for Doors and Windows" and not the normal "Great Stuff" that gets hard. Im going to give it a try after I finish all the painting, which should be finished this weekend. I will post up some pics after I get it all done....

[mbgmike]

Originally Posted by tonypaul

I spoke with a guy that has a spray foam business today, he does Rino lining and spray foam all from a moblie trailer. He said that he has done cars before in just the manner that I have questioned. He recommended spraying the inside cavities with WD-40 or like product, and then spray the foam. He offered to mine for free if I drove to a location that he was working at but my truck is a long ways off from being able to be driven. He suggested using "Great Stuff for Doors and Windows" and not the normal "Great Stuff" that gets hard. Im going to give it a try after I finish all the painting, which should be finished this weekend. I will post up some pics after I get it all done....

I would not use of the Brand Great Stuff for doors and windows on automobiles. We make Greatstuff and Its not reccomended at all.

[Kid]

2 pages of responses, but nobody stated they have used "spray foam" in the roof between panels. I would be concerned about the possibility of a deformed roof line.

[Zeke]

Kid is right, nobody has said they have sprayed expanding foam between the roof panels. I have thought about it and judging from the responses so have others but for me at least the consequences of something going wrong out weigh the benefits. I just don't have the guts to be the first and I wouldn't want to be the one to tell someone else to go for it just to find out.

The only experience I have had with expanding foam has been on aircraft. The blackhawk helicopter used to have expanding foam in the landing gear dragbeam, good and expensive stuff that would hold a 19,000lb aircraft up if the dragbeam ever cracked. The only problem was moisture would collect between the foam and the metal causing corrosion, you would never know about it until the dragbeam cracked, sounded like a gun going off. They don't use the foam anymore, just an epoxy coating and regular inspections.

This stuff would deform a roof line:

Estane® thermoplastic polyurethanes (TPUs) include elastomeric materials that bridge the gap between flexible rubber and rigid plastics. These materials offer unmatched toughness and durability in a flexible thermoplastic elastomer system that is easy to process in a wide range of equipment. The Estane® TPU portfolio of products offers high performance polyester - and polyether - based resins and compounds in a broad range of hardnesses to meet a variety of application needs.

[mbgmike]

Originally Posted by Zeke

Kid is right, nobody has said they have sprayed expanding foam between the roof panels. I have thought about it and judging from the responses so have others but for me at least the consequences of something going wrong out weigh the benefits. I just don't have the guts to be the first and I wouldn't want to be the one to tell someone else to go for it just to find out.

The only experience I have had with expanding foam has been on aircraft. The blackhawk helicopter used to have expanding foam in the landing gear dragbeam, good and expensive stuff that would hold a 19,000lb aircraft up if the dragbeam ever cracked. The only problem was moisture would collect between the foam and the metal causing corrosion, you would never know about it until the dragbeam cracked, sounded like a gun going off. They don't use the foam anymore, just an epoxy coating and regular inspections.

This stuff would deform a roof line:

Estane® thermoplastic polyurethanes (TPUs) include elastomeric materials that bridge the gap between flexible rubber and rigid plastics. These materials offer unmatched toughness and durability in a flexible thermoplastic elastomer system that is easy to process in a wide range of equipment. The Estane® TPU portfolio of products offers high performance polyester - and polyether - based resins and compounds in a broad range of hardnesses to meet a variety of application needs.

I have never sprayed it on these old trucks but have repaired many a vehicle here in Houston where it was done and seen and repaired the results. It is a favorite of amatuer body people in this area. This is not the first time its happened. I have seen the gutter area filled with foam, duct taped over and bondo'd over. No reason it would not work on a truck in good condition (rust wise) and properly treated. You have to use like I said before the correct stuff made for this. We have sprayed it in late model car repair. it does not deform the metal if you have the correct stuff. I would not use anything made by homes by any means. most all new cars even upper in cars have it like I said but they are properly treated. Not sure that it can be treated good enough on an old truck with existing rust.

[swamp rat]

Resurrecting an old thread hoping the thread owner might have a update???

[Sicklajoie]

Originally Posted by swamp rat

Resurrecting an old thread hoping the thread owner might have a update???

Thread owner hasn't visited this forum in almost 4 years.

[burnin oil]

I would be leary myself. Years ago one of the Navy Commands that spent a lot of time on the beach and in the surf tried to fill the Hummer frames to keep the salt water and grime out. The foamed ones rusted out a lot faster than the unfoamed frames. Honestly there isn't a lot of room up there so why even chance it?

[mike16]

I dont recommend it

Initially it will fill the voids dampen noise and vibration and bond to the steel inner surface.

over time the sheet metal panels will vibrate and the foam will begine to separate from the steel inner surface.

the humidity and moisture will get between the foam and the sheetmetal and the foam will hold that moisture against the bare sheet metal and cause it to rust exessively to the point where pin holes develope from the inside and grow.

at that point it will be impossible to fix or stop the rust.


It was tried on Homebuilt Air craft untill the corosion issue was discovered. no way to stop it or remove the foam later

[un4gvn!]

I painted houses for years. I used the yellowish/orange color inside the windows and door frames on houses before installing casings. I was restoring a 67 Buick GS at the time. When the foam expanded, it would dry hard but stay lite in weight. I had a good bit left after this one job and tried it out on the GS. I sprayed it inside the rocker panels. A little seeped out from some of the nooks and crannies. I let it dry and used a razor to cut it away. When time came to paint the car, you couldn't tell. It worked fantastic. There was no way moisture could get in. Everybody knows the rockers on the old GM A body muscle cars rust. I took a replacement Chinese rocker for our trucks (67-72) and welded a back to it like if it was on the truck. I sprayed an expansion foam from Lowes inside it and let it dry. Not only did it seal the voids but added considerable amount of strength to it. My son was impressed. He had a 67 C10 hood that always shook going down the road. He sprayed some under the braces. Let it dry and cut away the extra. We took it for a test drive. Worked great. A hood has a lot of sheet metal spread out. It did NOT reform it at all. Looked great after painting it. One thing, if you are planning to remove the foam later, goooood luck. Sorry for making this into a novel.

[Bigdav160]

Personally I wouldn't do it unless the metal has been treated with paint or epoxy.

My PO used fiberglass mat in several areas. I have rust problems everywhere it was used.

[sbrban]

I wouldn't do it. I work on vehicles every day, and see a lot of rust coming through....and the most common rust spots are where the manufacturers use foams for either sound deadening or structural strengthening purposes. The foams WILL either absorb or retain the moisture and cause pockets of corrosion.

[mike16]

Originally Posted by un4gvn!

I painted houses for years. I used the yellowish/orange color inside the windows and door frames on houses before installing casings. I was restoring a 67 Buick GS at the time. When the foam expanded, it would dry hard but stay lite in weight. I had a good bit left after this one job and tried it out on the GS. I sprayed it inside the rocker panels. A little seeped out from some of the nooks and crannies. I let it dry and used a razor to cut it away. When time came to paint the car, you couldn't tell. It worked fantastic. There was no way moisture could get in. Everybody knows the rockers on the old GM A body muscle cars rust. I took a replacement Chinese rocker for our trucks (67-72) and welded a back to it like if it was on the truck. I sprayed an expansion foam from Lowes inside it and let it dry. Not only did it seal the voids but added considerable amount of strength to it. My son was impressed. He had a 67 C10 hood that always shook going down the road. He sprayed some under the braces. Let it dry and cut away the extra. We took it for a test drive. Worked great. A hood has a lot of sheet metal spread out. It did NOT reform it at all. Looked great after painting it. One thing, if you are planning to remove the foam later, goooood luck. Sorry for making this into a novel.

I used it in the rockers of a 68 VW bug. The rockers were already totally rusted out. I blew it in, let it dry then shaped it to what the rockers looked like. primed and painted it and sold that pig ASAP. dont know what happened after that.

[ls1nova71]

I have a buddy who sprayed it inside the deck lid of a 69 Cutlass and it warped it beyond repair. I wouldn't chance it personally.

[hdff]

Originally Posted by tonypaul

Im really trying to get it quite as possible inside the cab.

want a really quiet truck, go down to the chevy dealer and buy a new one

[ls1nova71]

Originally Posted by hdff

want a really quiet truck, go down to the chevy dealer and buy a new one

Well there's a $50,000 solution.

[swamp rat]

I thought his idea was a bad one myself, i was curious if he was willing to share his results with us. I saved this thread back then and just found it the other day, had to ask.....