sound deadening

[brewpa]

I have been following posts for dampening sound in doghouse using Dynamat or Fatmat, both of which I find expensive. In Lowes today looking at foil backed 3/4 inch rigid foam insulation and a 4x8 sheet is under $10. So question is has anyone used this product to dampen sound and if so any particular installation tricks?

[jb1911]

Doesn't sound very "bendy".

[brewpa]

I know it doesn't sound flexible but looking at doghouse from cabin, it looks pretty angular and wondering about cut to fit.

[brucev]

Don't look at just the price. You may be making a long term investment. Also, you need something non-flammable and that can handle temps of probably 200 degrees or more. I can't decide between Fatmat or Dynamat. Fatmat is less expensive but most everybody on the forum are using Dynamat.

[brewpa]

Flammability an issue but put foil face towards heat? How flammable is Dynamat or Fatmat? Thanks this keeps me thinking

[revjeffrey]

I did sound / heat proof ours with the Dynamat self stick product. IMO I do not think the hard foam is a good idea. I'm not saying it couldn't be done. But the adhesion, forgiveness and final outcome in the Dyanmat or like product makes for a Factory Installation & Worth the $$$.. I used my extra outside above wheels trying to "cool the floor" where my feet rest while" driving.

[Bob Denman]

I found the perfect solution to this:

Fifty years ago; I started listening to Hard Rock 'n Roll music... at full volume!

Nothing is too loud anymore, but some things are a bit too quiet...

[Whirnot]

I went the fatmat route and am pleased. There are many areas that a ridged panel will not be able to cover, and then how do you attach it. Fatmat and Dynamat are flexible and will give if necessary.
We recently returned from a 3500 mile trip and we often commented our Vegas now sounds just like row 8 in an airbus A319. It just purrs along.......

[brewpa]

So in looking at Dynamat Extreme it is .067 inches thick and one person put Hoodliner (1mm thick)on top of Extreme.
Looking at Fatmat it is 3/4 inch thick so would I get better sound dampening with thicker material or am I missing something here?

[SuperD]

I used the Hoodliner and Extreme both, as recommended by DynaMat. First layer was the Hoodliner with seams sealed by DynaMat tape, then Extreme, again sealed with tape. Big reduction in noise, NO heat at all from the doghouse now. DynaMat is a little more expensive but you get what you pay for! Would do it again.

[Whirnot]

The fatmat I used is about 8 mil thick. It works .

[carlgorski]

Originally Posted by brewpa

I have been following posts for dampening sound in doghouse using Dynamat or Fatmat, both of which I find expensive. In Lowes today looking at foil backed 3/4 inch rigid foam insulation and a 4x8 sheet is under $10. So question is has anyone used this product to dampen sound and if so any particular installation tricks?

It’s expensive because it is a good product and easy to apply. Why cut corners to save a few dollars when you know it works.

[Finch1408]

Recently got 2 rolls of foil in A/C - Heat Dept @ Lowe's. Self stick, about 1/8" thick. Also roll of Aluminum tape. Did Doghouse and under hood. Works well, IMHO

[Mel556180]

Originally Posted by SuperD

I used the Hoodliner and Extreme both, as recommended by DynaMat. First layer was the Hoodliner with seams sealed by DynaMat tape, then Extreme, again sealed with tape. Big reduction in noise, NO heat at all from the doghouse now. DynaMat is a little more expensive but you get what you pay for! Would do it again.

Attachment 7726



Attachment 7727



Attachment 7728

SuperD, I’ve read the Dynamat damps down vibrations coming through the housing, while the hoodliner insulates to block heat and sound.
So it would seem best to apply the dynamat directly to the housing inside, then cover with the hoodliner.

Am I missing something here?

[carlgorski]

Originally Posted by Finch1408

Recently got 2 rolls of foil in A/C - Heat Dept @ Lowe's. Self stick, about 1/8" thick. Also roll of Aluminum tape. Did Doghouse and under hood. Works well, IMHOAttachment 7737Attachment 7738

I am sure it helps with heat but what about sound?

[SuperD]

I just did it the way DynaMat recommended, maybe I did it backwards but it works. There is a lot less noise.

[Finch1408]

Originally Posted by carlgorski

I am sure it helps with heat but what about sound?

Yes. I downloaded decibel meter app to my phone and measured sound at driver seat while reving engine to 1,500 rpm before and after. I think the difference (improvement) was worth the minimal cost of material. Haven't been on open road yet though. We'll see. Worst cases scenario, I add another layer. Good luck.

[SuperD]

Insulating the doghouse stops heat and makes a reduction in noise, mostly while cruising on the highway. There is still a lot of noise from the floor and dash area. I think adding insulation under the floor of the drivers area would help a great deal but haven’t gotten to that yet.

[Kev]

Originally Posted by SuperD

Insulating the doghouse stops heat and makes a reduction in noise, mostly while cruising on the highway. There is still a lot of noise from the floor and dash area. I think adding insulation under the floor of the drivers area would help a great deal but haven’t gotten to that yet.

Just came back from a trip after installing Dynamat and was happy with the results.

[Tupelo Kid]

3M 4014 SOUND AND VIBRATION DAMPING PANELS
from Aircraft Spruce & Specialty Co in Atlanta, Ga.
Great stuff for this purpose. I installed it in corp aircraft for 40 years.
I removed the heat shield material from the doghouse, installed sound damp and re-installed the heat shield. Love the outcome.
I do plan to cover the floor and other areas soon but will use the fatmat for that.

This photo is full sound damp foam before heat shield reinstalled.