Sound Deadening Replacement

[Bailes1992]

When I stripped out my arch liners for undercoating I found a sound deadening pillow in each arch. Both of these pillows were soaking wet and muddy so I made the decision to ditch them.

So far I can't tell much of a difference, if anything, but I would like to replace them as they were obviously put there for a reason.

Any suggestions for something that isn't absorbent and wouldn't potentially harbour rust?

I do have some Dynamat in the garage, wondering if using it on the internal arch sections would be a better solution?

 

[CharBaby]

Polystyrene/poly-phenylethene/Styrofoam

I have thrown more of this stuff away from package deliveries. Some of the "poly" that I've received was really nice, flexible material ideal for what you are talking about. Large, thick and bendable. I don't mean that cheap stuff that breaks and leaves particles all over the floor and your cloths. I mean the really good stuff! I'd think that you can buy it at any packaging store or online???

Another idea: I've seen Youtube videos where guys would repair rust holes on their trucks with cans of "TOUGH STUFF". I've used it myself for insulation around home windows or where drafts may appear in older homes. However, you'd need to let it expand and dry overnight then trim out what you don't want so that the inner liner fits correctly.

 

[nickaluch]

What tire is that?

 

[Bailes1992]

What tire is that?

Goodyear Vector 4Seasons. Came with the car from the factory, I don't think they're as good as the Michellin CrossClimate 2 but I have no real data points other than my 'gut feel'. They did pretty well on the off road day I attended last month though!

I'll be fitting General Grabber AT3's next I think.

 

[Kira]

1) Careful with TUFF-STUFF or any other foam as they'll expand to where you don't want it and dry hard.
You'll be tempted to reinstall your inner arch then shoot the stuff in.
See if rubber cement will stick to the foam you find and go that route.

PERSONAL EXPERIENCE: Hats off to any car maker which put such an absorbent pad between gas tank and body.

 

[wings&wheels]

I would try the Dynamat, assuming it is the foil faced rubber/tar adhesive product. They adhere to the panel, so should not trap anything. I'd be sure to deal with any paint chips thoroughly before applying. Surprised the OEM puts what appears to be essentially a sponge there...

Some prior owner put Dynamat on the underside and inner fenders of my old Land Rover. Bit of a pointless effort on an old Series, but I will say the stuff is durable.

 

[JHZR2]

I’d be careful with anything that will adhere to a surface. That’s the making of a moisture trap and rust hole. I think some closed cell foam or rubber mat would be best.

 

[Bailes1992]

I’d be careful with anything that will adhere to a surface. That’s the making of a moisture trap and rust hole. I think some closed cell foam or rubber mat would be best.

That's why I'm thinking of using the Dynamat but fixed to the inside of the arch, i.e. inside the car.

What I don't know is how good Dynamat is as reducing the sounds this pillow was obviously employed for.

 

[JHZR2]

That's why I'm thinking of using the Dynamat but fixed to the inside of the arch, i.e. inside the car.

What I don't know if how Dynamat is as reducing the sounds this pillow is obviously employed for.

Yeah it’s a good question. The dynamat would reduce vibrations and maybe some sound transfer. I’m not convinced that the pillow was doing much anyway though.

If you’re that concerned, just add something on the outside, just not something that will trap or hold water. Closed cell smooth exterior foams might work well. You might even try to adhere to the arch liner versus the structural metal itself. Something like pipe insulation tape that is closed cel may work.

 

[97prizm]

When I stripped out my arch liners for undercoating I found a sound deadening pillow in each arch. Both of these pillows were soaking wet and muddy so I made the decision to ditch them.

So far I can't tell much of a difference, if anything, but I would like to replace them as they were obviously put there for a reason.

Any suggestions for something that isn't absorbent and wouldn't potentially harbour rust?

I do have some Dynamat in the garage, wondering if using it on the internal arch sections would be a better solution?

Sound deadening spray. They sell it at auto parts stores.

 

[Cujet]

I would avoid any form of insulation there. Instead, coat with a wicking, waxy, corrosion inhibiting compound to ensure a long lifespan. Consider heating with a heat lamp, prior to application.

A favorite:

 

[Pew]

I used the CCF and CLD tiles that I installed inside the car into the front wheel wells of the cx5. I know some models will have some sort of foam in there to reduce certain sound freqs but the cx5 didn't have any foam up there and I did not notice any improvements in road noise since the wind noise of the wind deflectors is much louder. If I was to do it again, I'd just do those MLV sheets instead; but mlv is expensive so that's a all-in route.

 

[brianl703]

Another idea: I've seen Youtube videos where guys would repair rust holes on their trucks with cans of "TOUGH STUFF". I've used it myself for insulation around home windows or where drafts may appear in older homes. However, you'd need to let it expand and dry overnight then trim out what you don't want so that the inner liner fits correctly.

Spray that expanding foam with water as you apply it, it will expand more and cure much quicker.

 

[PF52]

Spray that expanding foam with water as you apply it, it will expand more and cure much quicker.

Like Gorilla Glue eh? They say apply it to moist surfaces for best results but I never understood why.

 

[Rust_Belt_Pete]

Polystyrene/poly-phenylethene/Styrofoam

I have thrown more of this stuff away from package deliveries. Some of the "poly" that I've received was really nice, flexible material ideal for what you are talking about. Large, thick and bendable. I don't mean that cheap stuff that breaks and leaves particles all over the floor and your cloths. I mean the really good stuff! I'd think that you can buy it at any packaging store or online???

Another idea: I've seen Youtube videos where guys would repair rust holes on their trucks with cans of "TOUGH STUFF". I've used it myself for insulation around home windows or where drafts may appear in older homes. However, you'd need to let it expand and dry overnight then trim out what you don't want so that the inner liner fits correctly.

Just like that awful OEM sponge it will cause really bad rust.
Get to the wheel wells from the inside and spray some sound insulation on the outside not inside of wheel arches.
Now I want to pull my wheel well liners and check. So dumb.

 

[brianl703]

Like Gorilla Glue eh? They say apply it to moist surfaces for best results but I never understood why.

It's because expanding foam and gorilla glue are both polyurethane prepolymers which react with moisture to cure. One of the products of the reaction is carbon dioxide, which explains the foam.

 

[SHOZ]

My Taurus had some sort of polyester fluff behind waterproof covering that worked good. The poly didn't absorb water and it would drain down from gravity so they didn't stay wet.

Looks like this

 

[nickaluch]

Spray that expanding foam with water as you apply it, it will expand more and cure much quicker.

It expands big time it could push out the fender or anything else in its way a little goes a long way

 

[brianl703]

It expands big time it could push out the fender or anything else in its way a little goes a long way

It doesn't expand with that much force, it's a problem with vinyl framed windows but anything more substantial than that won't be deformed by it.

 

[KrisZ]

I wouldn’t install anything there. The area obviously gets wet and grimy. You don’t want anything in there that can trap moisture. The material itself may not absorb moisture, but it can still trap it in some way between itself and the metal.