I am currently financially strapped and so i cant spend money on sound deadening products like dynamat and fatmat, second skin etc etc.... anyway i was wondering if there are any other ways to stop the trunk from rattling...... I tightened up all the bolts in the trunk which helped very little but it still helped nonetheless. I noticed under the carpet in my trunk is a layer of stock sound deadening im guessing. It is also surrounding the 6x9's on the rear deck in the car. I have several cars at my house that are out of comission, if that layer of fabric under the carpet is an actual sound deadener, i was wondering would it be possible to somehow jerry-rig a way to stick it to the trunck lid..... If it will actually help a considerable amount that is. Thanks

~MadroX

Freebie: take off the trunk latch, part on the car, not the trunk and elongate the mounting holes so you can move it down more and the trunk will close MUCH tighter.

Aluminum foil Peel & Seal at Home Depot is like $15 for a 6" x 25' roll and will give you 2 solid layers on a normal sized trunk lid. Clean the trunk with brake cleaner and warm the P & S with a hair dryer. I've used it all over my car and have had NO problems with it. And I have a black car, so obviously it gets very hot in the summer. Make sure to overlap the ends as you apply it, as that seems to make it stick even better.

Freebie: take off the trunk latch, part on the car, not the trunk and elongate the mounting holes so you can move it down more and the trunk will close MUCH tighter.

Aluminum foil Peel & Seal at Home Depot is like $15 for a 6" x 25' roll and will give you 2 solid layers on a normal sized trunk lid. Clean the trunk with brake cleaner and warm the P & S with a hair dryer. I've used it all over my car and have had NO problems with it. And I have a black car, so obviously it gets very hot in the summer. Make sure to overlap the ends as you apply it, as that seems to make it stick even better.

is there a considerable difference in deepness of bass and/or crispness of bass?

ahhh crispness

ahhh crispness

I use expanding foam in my ride. You can get Great Stuff at Home Depot for like $5.00

^ I filled my trunk lit with it not including the mechanical and electrical parts. It made it solid as could be. Filled the rear doors in my yukon entirely with it, enormous difference in rattling, and cheap to do. Hot days doesn't effect it either.

When you use the expanding foam in the trunk lid. Do you just spray it in the holes in the trunk lid until it fills up that whole negative space between the inner and outer trunk lid? Mind you I have a 1996 Taurus.

I had a late 90s mustang gt, so a small lid. I covered the important stuff so the foam wouldn't get to it. I removed the carpet that covers the lid and just put 3-4 cans in. I filled up all of the structure, where there is a stiff beam meeting sheet metal. Actually I just made sure I filled every hole possible that wouldn't interfere with it's function and filled 'er up, then cut off the excess. A few sound deadening sheets across the large pieces of sheet metal and done. Worked wonders for me. I filled in all the cracks in the entire trunk that way.

To stop rattles (ie two pieces of plastic or metal from hitting each other) then you can use anything like weather stripping, non-hardening modeling clay, etc.

If you want to stop plasitc or metal from vibrating, you need to mass load it (add weight). Peal and seal can help, but there are problems associated with it. 1) it stinks and doesn't stick all that well (unless its on the floor) 2) it's light and thin 3) by the time you get enough of it on there to have a significant effect, you can buy RAAMmat instead.

If you want to kill sound transmission (road noise) then you need a barrier. The carpet you mentioned would do the trick here. I have 150ft^2 of synthetic carpet padding in my car and it worked great. It's the same stuff they use in cars. Looks like horse hair.

hmm, my trunk comes with sound deadener, lol

But i use sponge and expanding foam.

Watch out for the foam though, because like ti said it expands, lol, my buddy kinda got it all over his car, pretty funny but nothing a razor and some soapy water won't remedy.

I've used rubberized spray-on undercoating on a trunk lid before. Worked great and it was cheap as hell, about $6 a can from Wal-Mart in the automotive section.

i used that stuff on the back of my door panels, looks like it would work well on anything besides my door panels (i had about 3 cans of the undercoating and 2-3 layers of rammat and still had vibrations.

is the undercaoting spray on REALLY effective?

J

I used that undercoating spray on a lot of panels, especially those on the outer skin of the car. It worked to an extent. Not as good as some peel and stick products because it's hard to get the weight they add, but a good product for the $ imo. worth spraying in hard to reach places, and a permanent thing you don't have to worry about coming off.

If you are going to use expanding foam... don't just fill the panel. Do it slowly, it is activated by O2... so if it can't get any, it will take a long time for it to cure.

If you are going to use expanding foam... don't just fill the panel. Do it slowly, it is activated by O2... so if it can't get any, it will take a long time for it to cure.

I have also seen minimal expanding foam. It does not get as wild as the normal stuff.

I use the stuff that doesn't expand much... it also stays soft. No wrinkled panels ftw.

I use the stuff that doesn't expand much... it also stays soft. No wrinkled panels ftw.

That's what I'm worried about as the car is black and will show any waves in the trunk lid. Anyone have problems with their trunk lid bulging after using expanding foam?

Although I'm considering doing a sealed off front firing set up now, so trunk rattles will be a thing of the past...

i drilled a few extra holes along the tunnel that i was filling and just filled the hollow part up about 3/4, i didn't get any kind of bulging

Couple of points on this. Expanding foam is really useful for filling voids and locking panels to each other to prevent flex and resonance. You want to be very careful which type you use. You want the polyurethane varieties, normal or minimally expanding. Be very careful with the latex versions that stay soft. The absorb moisture and can cause rust where they touch sheet metal.

Beyond that, The tightening everything in sight is a good first step whether or not you have the dough to go all out with sound deadening. Nothing worse than sealing a rattle in.

The first step in proper deadening is a vibration damper like Dynamat Xtreme, Damplifier, RAAMmat, etc. These work by adding mass to lower the resonant frequency, stiffening the panel which actually raises the resonant frequency and by dissipating vibration via internal stresses. The last is the viscoelastic damping you here about. Asphalt is not viscoelastic, so it can never provide this important function. I also cation people to be very way of individual claims of success with asphalt. Many, many people have had serious problems including melting. Proper installation procedures can improve initial adhesion, but nothing can guarantee long term success. Ironically, the very act of heat asphalt mat to make it stick better reduces its long term stability. Batches of asphalt are very inconsistent and there is no way to pre-judge the outcome. It is a very risky undertaking. In point of fact, you can get equal results with MUCH less butyl mat, so it isn't even cheaper.

You really need to get the vibration damper right up against the sheet metal, so it isn't really worth doing anything they will prevent you from doing a proper job in the future. I suggest waiting.

Welcome!!!