minimizing the cost of sound deadening

[Rsx_03 10+ year member]

basically just trying to cut down the cost of sound deadening my hatchback

for the horizontal areas of my car (aka trunk floor and cabin floor) i was thinking instead of using raamat just use fatmatt. since its 80 mils thick and the cheap adhesive i dont think will slide around. for the vertical areas ill use raamat. for vertical areas (aka doors, trunk walls, etc.) use the raamat

for gaps in doors, etc use thin pieces of metal with silicone and self taping screws.

fill in large gaps with expanding foam and small gaps with that window foam.

Click to read more...

 

[Fast1one 10+ year member]

I had the same plan. Seems feasible as long as you dont live in 110 plus weather all the time...

 

[mlstrass 5,000+ posts]

For the Horizontal surfaces use Peel & Seal from HD or Menards. Like $12 a roll.

 

[CBFryman2 5,000+ posts]

Peel and Seal is like $1 a sqft. May as well buy eDuh crap.

 

[Rudy 10+ year member]

FatMat is 80mils in their dreams. It's Peel & Seal, so if you are determined to use asphalt, just go to Lowes.

A better approach is to use less of a better butyl mat. Even if you need to lay it down in 2 or 3 inch strips separeted by 2 or 3 inches, the results will be better. Asphalt is a really poor vibration damper that gets worse the further you get from 68°F. Even though it won't fall off the floor, it might still melt and ooze all over the place. To add insult to injury, it leaches toxic gases and becomes less effective as the toxic volatiles escape.

Just be smart and you can get by with much less than you think. Concentrate on the centers of big panels that aren't braced. Use expanding polyurethane foam to fill in big gaps like quarter panels (be careful). Closed cell foam is relatively cheap and adds a lot to the project.

 

[duece212 5,000+ posts]

I used fatmat on the floor and back cab wall in my ext cab s10, and dynamat extreme on the doors and roof.

That fatmat did a good job on the floor/backwall, did two layers, I used a heat gun with it just to make sure it stuck. Its not the easiest to apply but its cheap and gets the job done pretty well for what it is.

 

[Rsx_03 10+ year member]

yea i live in flordia heat is a big issue for me

i read a while ago that closed cell foam doesnt do much. ill read up on that again.

my real concern is road noise (low profile tires + lower + being made by honda = hella lotta noise .. at least for me) i would think you would have to cover all the floor and wheel wells, leaving gaps would still let road noise leak through?

 

[BassAce 10+ year member]

yea i live in flordia heat is a big issue for mei read a while ago that closed cell foam doesnt do much. ill read up on that again.

my real concern is road noise (low profile tires + lower + being made by honda = hella lotta noise .. at least for me) i would think you would have to cover all the floor and wheel wells, leaving gaps would still let road noise leak through?

What do you drive and what year is it Rsx_03?

 

[CBFryman2 5,000+ posts]

I'm betting an 03 RSX...

 

[Rudy 10+ year member]

Well, you can't have everything. Leaving gaps isn't as good as complete coverage, but it is better than using shite. If money is the biggest concern, you have to compromise. Sound deadeners are primarily vibration dampers and will work without full coverage. They have some barier effect which is reduced by partial coverage.

Closed cell foam isn't as good as open cell foam at absorbing sound, but open cell foam isn't really suitable for inside a car - it holds moisture. Again, compromises. It is way better than using nothing.

Ideally you want full coverage with a quality vibration damper. Then at least one layer of 1/8"-1/4" of closed cell foam. To really quiet things down, you need an actual barier product, either lead or mass loaded vinyl sandwiched between two pieces of foam.

I'm just trying to show you a better way to do it cheap, rather than using crap. If you want to really invest in the project you can do a lot more.

 

[Imtjnotu 5,000+ posts]

bestbuy said they would do my hatch for 189 everything

 

[xterra_on_22s 10+ year member]

yea i live in flordia heat is a big issue for mei read a while ago that closed cell foam doesnt do much. ill read up on that again.

my real concern is road noise (low profile tires + lower + being made by honda = hella lotta noise .. at least for me) i would think you would have to cover all the floor and wheel wells, leaving gaps would still let road noise leak through?

not to mention that miami roads aren't the best built roads either.

 

[dleccord 5,000+ posts]

peel and seal's price went down? it was about $21 over a year ago.

 

[Rsx_03 10+ year member]

alright so now i want to get 62 sq ft of raamat (60 mils), 42 sq ft of closed cell foam (1/8"), that adhesive spray to stick down wires and stick foam to stuff, which is 190 shipped

do you know a good place to order Mass Loaded Vinyl? or could i pick it up at a fabric store or home depo?

as well as i am going to make a fiberglass mold (not permanent) in my spare tire well to hold my amps and such, do i need put sound deadening there since it will be covered?

 

[Rudy 10+ year member]

Mass loaded vinyl? Second Skin and B-Quiet sells it or just Google it and you'll find lots of sources. Not something you are likely to find locally.