The Poor Man's Dynomat

[Aaron]

I was bored on a Sunday afternoon and after getting out of my car while my system was on I noticed that there is the most obnoxious rattle when the bass hits (2 12"s).

So after brainstorming for a while I decided that dynomat was good, but out of the question because I do not want to drop that much money.

So I remembered a while back using this stuff in my basement with my dad to insulate a part of the wall. It's in a spray can and it's just foam insulator that expands and dries, filling in empty spaces.

So I started with the trunk door, filling in every open space I could find, then I pulled back all the carpeting along the sides and started filling in some of that area, but not all, just basically the direction that my subs are hitting in. I then went over it with a piece of wood to give it a flush look to it. It sticks to anything and will not let go.

So at $4.99 a can and my project requiring only 2, I'd say my $10 investment was well worth it. No rattling. It is much louder inside my car, but with all the windows up, standing near the car, you can barely hear anything. Inside it sounds amazing.

I got it at home depot, just ask for the foam insulator in a can.

Don't get it on your hands. My friend thought he was funny putting it all over his hands, and found out the consequences of that little game.

That's was just my little project that worked out well, something that doesn't happen much when I start getting new ideas and playing around with my car :D

[VanishingImage]

i had the same idea and had some cans,they were blocked up by the foam since it had dried throughout the little plasitc tip.....But becareful and check the areas like the trunk lid to make sure the foam isn't forcing the thin metal to expand,that was one thing i was worried about on mine.

[Pte Socks]

waht happens if that metal expands too much? bust-all-to-hell? or does it deform? or something else

[nineteen88ga]

I know someone who went buck wild with the foam trick in his trunk and trunk lid and it expandes so much that the trunk lid looks like someone beat on it with a hammer from the inside. The sad part is, he was in my MECP classes too. Is that someone you hire to do installs for your shop? lol

[car audio dave]

there are actaullya lot of tricks to killing rattles other than dynamat or tar mat materials. that foam is one of them, another is material padding, and yet other is carpeting. anything thatll fill up dead space, big or small.

[zero53121]

dont get it in your hair. u will hate life. seriously. i was doin that to my trunk and it dripped into my hair and boy did it hurt tryin to get it out. i used gas to get it out but i didnt think about that till after a hour of tryin to get it out.

[02gtwank]

yeah that foam expander works awesome i got it all over my trunk but i wouldnt worry too much about expansion itll bleed outta the holes u sprayed it in before itll deform metal thats just a bit of commin sense but does anyone got ne pointers on how to get the bumper to stop rattling

[tenspeed]

You can get that foam in regular and less expanding.

People were blowing out drywall when sealing houses with the regular expansion.

[nineteen88ga]

holy old thread batman....and go ahead pump your trunk lid full of the expanding foam. I've definately seen it deform pannels. Your never going to stop ALL audio rattles at least when dealing with alot of bass.

[mayhem_audio]

i can tell you their is a diffrence on a db drag team i was on he used peal and seal on the roof we took readings removed it and replace with dynomat extreeme gained half a db and we only did that to a 3 foot section to the roof

[inferno]

Originally posted by nineteen88ga
holy old thread batman....and go ahead pump your trunk lid full of the expanding foam. I've definately seen it deform pannels. Your never going to stop ALL audio rattles at least when dealing with alot of bass.

ive filled my ga up with the foam and never had a prob. and i fill my trunk lid in every nook. my entire spare tire hole is filled and my rear quaters

[ccjunior2008]

I've been lookin around for sumthin to prevent trunk rattle and dynomat is way out of my price range. I might have to try some of that one of these days.

[MantaGreen97]

Originally posted by nineteen88ga
I know someone who went buck wild with the foam trick in his trunk and trunk lid and it expandes so much that the trunk lid looks like someone beat on it with a hammer from the inside. The sad part is, he was in my MECP classes too. Is that someone you hire to do installs for your shop? lol

LOL. Unbelieveable.

Yeah when I started reading this thread I was like--->:eek: to know that he'd actually gone through and done the trunk with it.

My advice is to not do this as expanding foam (usually polyurethane) is stronger than the sheet metal your car is made of and can/will damage body parts and or expand body seams, etc. The damage will be pretty bad and it will either be very expensive to repair or irrepairable.

There are lots of Dynamat alternatives, including competitor products, roofing products, sprays and brush on rubber/ashphalt products, etc. but this is not really one of them.

Though you may be able to use it and not expand anything visually, you might rupture or compromise seams in the body which might lead to water leaks, rust or other failures don't the road. Also even if you're able to do it with none of that, is it really worth the [rather high and expensive] risk?

Plus expanding foam is pretty messy IMO, and you can't control it's expansion or shape--so it isn't going to look pretty either.

As an aside, have any of you guys ever seen that movie about the sinkhole in some city that they have to repair? I think it was some made-for-TV type movie, but anyway in the movie the way they stop the sinkhole is to use expanding polyurethane. Though it was a pretty lame movie being made-for-TV and all, the premise of the solution isn't really that unrealistic. Expanding polyurethane foam can indeed exert a lot of force when it expands...

[Conley]

Well here's my $.02. Why are people spending hundreds or thousands of dollars on their systems and cheaping out in other areas? If you don't have the money to get the proper materials, don't buy the system! It's that easy.

Conley

[matts]

i like dynamat xtreme personally

[nineteen88ga]

Originally posted by matts
i like dynamat xtreme personally


...at least somone knows how to spell it correctly....:lol:

[matts]

i proud miself on corect speling :D

[02gtwank]

7 bucks a can u cant beat it and great stuff from home depot worked wonders for my 2 15" solo barrics i barely have ne rattle

[ancona46]

some household carpet works wonders if u put it in the quarters wehre to monsoon amp goes and the other side that has the vent,...and u can always take it out