Need Ideas on how to deaden rear quarters

[SpeedEuphoria 10+ year member]

Hey I have an '03 Dodge Stratus Coupe(built on the Mitsubishi galant/eclips platform)

Anyway I have the complete interior out except for dash. I have been deadening everything but the rear quarters I cannot get to very easy.

I may post a pic, but basically there is an inner sheet metal panel similar to door skins except its almost touching the outer skin of the rear quarter.

At this point I was thinking just filling it up a ton with expanding foam but that stuff isnt very dense so???

Any other thoughts, cant get a paint brush in to do liquid deadener either.

Help me out

Click to read more...

 

[audioholic 5,000+ posts]

Look into spray-on deadeners, most quality deadener companies offer one.

 

[brian84corvette 10+ year member]

cant get a paint brush in there ?

I was gona suguest maby a mini hot dog roller on a long semi flexible piece of metal rod if you could snake it in there

?

show us a pic of the area

 

[Papermaker85 5,000+ posts]

reinforce the panels with 1/4 ply and if they are touching put deadner inbetween..

 

[Rudy 10+ year member]

What are your trying to accomplish? Density is probably only going to be an issue if you are trying to block sound.

 

[SpeedEuphoria 10+ year member]

Well would like some resonance protection and blocking noise also.

I dont have a good pic of the area and its hard to get a pic that shows what I'm dealing with.

Basically thers the outer quarter skin, then like 1/2" inside that there is another sheet metal pannel that is on the lower 3/4. So you cant get any CDL's on the outer skin (the bottom 3/4 of it) as there is no way to get to it. Well I could cut it out and weld it back in but that seems a bit much, also dont have anything to cut it with easily except snips as the sawzall will hit the outer quarter.

Anyway I sprayed some deadner in there good.

I wanted to spray the crap out of the area with expanding foam but also want to put some noise blocker in(aka neoprene 3/8") so I may slide the neoprene in then expanding foam the crap out of it??

 

[Rudy 10+ year member]

Well would like some resonance protection and blocking noise also.
I dont have a good pic of the area and its hard to get a pic that shows what I'm dealing with.

Basically thers the outer quarter skin, then like 1/2" inside that there is another sheet metal pannel that is on the lower 3/4. So you cant get any CDL's on the outer skin (the bottom 3/4 of it) as there is no way to get to it. Well I could cut it out and weld it back in but that seems a bit much, also dont have anything to cut it with easily except snips as the sawzall will hit the outer quarter.

Anyway I sprayed some deadner in there good.

I wanted to spray the crap out of the area with expanding foam but also want to put some noise blocker in(aka neoprene 3/8") so I may slide the neoprene in then expanding foam the crap out of it??

The thing to think about when using a sprayed damper or expanding foam on a panel that is visible from the outside is that you are pretty much precluding future repairs to that sheet metal, even something as simple as PDR. I'm currently pulling both things out of a car and I really can't overstate how much I'm regretting having put them in there.

The important point about barriers is that you really only need one layer between what you are trying to block and your ears. I'm assuming here that the neoprene you are talking about is very dense and not neoprene foam which wouldn't block much more than expanding foam. Sound doesn't care if it hits the blocker on the interior structure or the inside of the full quarter panel. This works both ways - the barrier will also protect the outer skin from energy from your sound system.