Hey guys I followed a modification on here and put down some sound proofing material which was basically duct insulation with a self adhesive on it. I thought about it a little more lately, its been about 3 months since I did it, and I was curious if you guys think it would rust out the cab on the bottom from trapping moisture? I put the insulation down first then followed by some carpet pad ( the same stuff that comes with it from the factory) Then the actually floor mat. I put insulation over but not in the large grooves in the floor. I was told those were to collect the water because of condensation and not to fill those on. Do you guys think this will be an issue? Thanks for any help guys I would greatly appreciate it.

 

I personally have never heard of that. No matter what you have down on the floor and you get moisture down there it will promote rusting of the floor panels. Shouldn't make a difference if you have insulation or just carpet....the moisure will still be there.

I have not heard that the groves are there for moisture but I guess it could be true. I've always understood those groves are there to give the panels more strength and rigidity...not to channle moisture. A flat peice of sheetmetal will not have near the strength as it does if you put those ridges in. Same philosophy as why you see ribbing in cast components such as engine blocks, trasmissions and rearend housings.

 

The grooves are there to strengthen the floor and keep it from oil canning. Ever lean up against a car or truck and you feel the panel behind you pop in and as soon as you get off it pops back out? That's oil canning and if it did that every time you put your foot on the floor it'd be unnerving to say the least.

What 82 said. Rust is really oxidation of metal and needs two parts. Moisture and oxygen. The only problem I see is that with the foil backing it may help trap water down there and if the adhesive isn't fully down you can get movement that will move fresh air in from time to time and yeah it could promote rust.

In reality I don't think it's enough to worry about. If you are worried, put a coat of rubberized undercoat down first, then the insulation.

 

I put 2 coats of POR-15 down on my Nova during my rebuild. Expensive stuff but love it. Probably overkill here....the undercoating is probably a better way to go and gives you a little insulation to boot.

 

ok thanks for info guys. I probably will leave it for a year or so and take it off and see whats going on down there. I have some POR 15 but i plan to use that for the undercarriage right now. Thanks for the info.

 

i would be careful with that, i did that same process and i pulled a little bit up 2 weeks ago and my entire floor was covered in surface rust,

i wirewheeled it down and painted it with chassis black from napa (similiar to por-15)

i then ordered some Damplifier sound deadener made by second skin, its relatively easy to put on, it works much better and it wont allow for moisture to get trapped

 

Nova? You have a Nova? What year? I like the old Nova's.

 

72...doing a frame off restoration. Didn't start out that way but the further you go...the further you go!!! know what I mean?? I realized one day that the only screw/bolt I had not touched was the trunk lock mechanism...so I took it apart jost so I can say I've touched everything on it. Pretty much all going back new, restored or fabricated. Just finished fabricating an entire new trunk with a fuel cell...now on to the floor boards...but need new welder first.

this is the car and the 427 going in!!

 

I had a '73 Olds Omega (same body style) at one time. I built a 450hp Chevy 302 for it. Sweet car, ran 1/4mile in the 10's. I love that body style. I would love to find something similar again, for the right price of course.