What deadener for roof?

[audioholic 5,000+ posts]

right havent taken the headliner off yet, will check it out
what kind of foam do you recommend? brand?

I've used expanding foam in the past in another car, just cheaper stuff in a can from lowes

I know from a performance aspect people do this to frame rails and structural parts to handle better, but they recommend against the cheaper stuff from lowes

here:

http://forums.freshalloy.com/showthread.php?t=162693

Just the cheap spray foam in a can from your local hardware store. I generally avoid "GreatStuff" brand, but it will work if no other brand is available.

 

[brian84corvette 10+ year member]

saw some one post somewhere - the spray can foam - comes in 3 diffrent expansion rates...

the one that expands the most - is the least dense foam when cured

middle expansion - is a more dense foam when cured

and the foam that expands the least - will result in a foam that is the most dense out of the 3 - so this is what I would think would be wanted

because the denser the foam is - the better job it will do at blocking sound.

maby use the middle expansion foam for large voids that need to be filled.

 

[slam 5,000+ posts]

i use wood

 

[blakflash 10+ year member]

Not to thread jack but right now I'm in the same boat. I was going to just spray foam it but wasn't turn on it adding more strength to it. Works well on trunk lids though lol.

I like the fiberglass idea. How thick of a layer did you use?

 

[audioholic 5,000+ posts]

saw some one post somewhere - the spray can foam - comes in 3 diffrent expansion rates...the one that expands the most - is the least dense foam when cured

middle expansion - is a more dense foam when cured

and the foam that expands the least - will result in a foam that is the most dense out of the 3 - so this is what I would think would be wanted

because the denser the foam is - the better job it will do at blocking sound.

maby use the middle expansion foam for large voids that need to be filled.

In this case, blocking sound is not the goal. Most roofs have strengthening ribs that run along them, but that only make contact with the sheetmetal in strategic places. The factory did not want to warp the outer skin by welding it solid. The spray foam will fill in any gaps between the sheetmetal and those ribs, effectively bonding the ribs to the skin all along their length.

For the fiberglass, just keep adding layers until you are satisfied with the results.

 

[blakflash 10+ year member]

Yeah I noticed the ribs in there. I got three sets of them in mine. And the flex isn't bad. not yet anyway. As I'm sure they would break off if I let them. I had the idea of welding braces in there but I don't want to run the risk of eating through the roof with it. I read in another thread that was a year or so old that you were going to try the glassing thing. Did you ever get around to it? I do intend to use a single layer of deadener to help hold in sound. But even before I began reading about it I had my doubts on it reinforcing against sever flexing that and it just seemed to expensive and ineffiecient. Guess I need to do some research in the flexibility and temperature tolerances on fiberglass products

 

[brian84corvette 10+ year member]

what about adding some bracing in the fiberglass work to the roof pannels ?

kinda like how a surf board has the wood strip running up the middle -

same idea - use some thin light pieces of wood like that after the first coat of glass - and then glass mat them in effectivly making cross bracing across the larger sections of un factory braced roofing ?

 

[groundpound4200 5,000+ posts]

have fun picking resin out of your hair....

 

[SPLaudio 5,000+ posts]

i would fiberglass the roof and buy a bucket of liquid deadener for the trunk. i just did my truck. 3/4 gallon in the floor and sides and 1 2'x4' sheep of mat to do the trunk lid..

 

[audioholic 5,000+ posts]

what about adding some bracing in the fiberglass work to the roof pannels ?
kinda like how a surf board has the wood strip running up the middle -

same idea - use some thin light pieces of wood like that after the first coat of glass - and then glass mat them in effectivly making cross bracing across the larger sections of un factory braced roofing ?

You can effectively make the actual subwoofer enclosure out of layered fiberglass, so I dont think the roof would require any additional strengthening procedures. If done correctly, even a few layers of fiberglass is still pretty thin, and can stiffen a panel quite well. If this still isn't enough strength for your application, look into something more extreme like a steel post/tube mounted from the floor to the roof (only really necessary in extreme SPL rigs, see Frankie Rio's car for reference if you dont know what I mean).

 

[SpeedEuphoria 10+ year member]

Any last advice,

pulled the interior out completely

just spray foamed the trunk, deck, A/B Pilliars, and roof supports(10 cans worth). Getting ready to fiberglass the roof.

I ended up buying some eDead for other areas(doors ect..), I plan to see how sticky it is then use adhesive also if needed.

I was going to scuff the roof then adhere the fiber mat to it, got a drop cloth down so I dont make a mess as most of the floor seems solid(better than the rest of the car) and I can see factory deading there also

 

[CHEMMINS 10+ year member]

Take pics!!!!

 

[SPLaudio 5,000+ posts]

get to work and yes take some pix bro..