Uh oh. My car smells like asphalt

**Rudy** · 05-22-2007, 01:49 PM

I wouldn't remove anything. As Abmolech suggests, adding a barrier is probably going to be your best bet. Look at lead and foam or masds loaded vinyl and foam composites.

**Abmolech** · 05-22-2007, 03:46 PM

A dampener is principally a decoupler. It transfers energy into the aluminium layer via an elastic material. The efficiency is mainly determined by the rigidity of the aluminium and ability of the material to maintain elasticity. Your gains have been through the blocking ability; there may be some if the vibration (frequency) of the panel is sufficient to make use of the decoupler. (Read large flat panel)

First determine your “weak link” In this case the glass at 6 mm thick will attenuate 125 Hz by 22 dB. Let this be your “guiding light” unless your will to replace the glass.

Sound travels with less loss through solid objects, (the main reason a decoupler works) therefore the biggest gain are going to be in reducing the source and maintaining the decouplers. Have a check of suspension bushes, engine mounts and exhaust supports. Generally the vast majority of noise will be through these. The engine vibration (around 100 Hz) will try to find a suitable panel to exhibit its noise. Any large flat panel will be the number one source. (Door outer, roof, boot and hood)
Next is tyre rumble, depending on the tyre and road coarseness, this will vary from 50 to 250 Hz. Inner door and similar panel work will exhibit this noise. Attacking this at the source (better tyre type) will gain the most.

Radiated noise is the next on the list.
Muffler, tyre, engine noise and wind noise are the primary culprits. This is where blockers are the “weapon” of choice. At these frequencies you can forget neoprene (except for a decoupler style operation) and closed foam attenuators. These use the principal of passing waves through a matrix, and transfer energy to heat. They are limited by diffraction, that is, they are required to diffract the wave. Diffraction is frequency related and therefore these only work on the frequency shorter than the width of the absorber. (Blocking ability aside)

Best blockers are lead, copper and aluminium; (well practical blockers) other choices are rubber and vinyl. 1/16 thick lead will attenuate 125 Hz the same amount as 4” thick wood. (44 dB) Your metal (steel) attenuates 125 Hz by 12 dB. I recommend lead, as it is easy to work with, (No sharp edges and cuts with scissors) 1/32 (0.5 mm) is a good as glass 6mm.

**bambam** · 05-23-2007, 11:40 AM

Originally Posted by nobb

Hi.

Well, I couldnt find any Peal n Seal locally. The only product that resembled it that I could find was Bakor Blueskin. It says its made out of rubberized asphalt. So I bought a roll of that and did my rear doors and trunk lid yesterday. My car hasnt been sitting in the sun (in the garage) and it already smells a bit like asphalt. The smell isnt too strong, but Im worried it will be worse if left out in the sun. Anyone have any tips? Please tell me this smell will go away after a week.

I installed FatMat in my car and WHOA, it smelled like asphalt s### really, really bad! It has been a coupe weeks and the smell is almost gone but it was rough for awhile. So far, doesn't seem to get any worse oh hot days.

**turbocad6** · 05-23-2007, 01:26 PM

hey man, thanks for the info & confirming that lead sheeting will be the next step for me.... I'm also going to tripple seal all the door openings as best I can to help a bit more with windnoise, I think the wind in the gaps of the panels is also a pretty big factor & a seal at this gap should help a bit... I have considered the possibilities of doing something with the glass, but there aren't really any practical solutions there at all, I guess it get's to a point that it's as good as it's gonna get too, Thanks again

**Rudy** · 05-23-2007, 06:28 PM

Originally Posted by turbocad6

hey man, thanks for the info & confirming that lead sheeting will be the next step for me.... I'm also going to tripple seal all the door openings as best I can to help a bit more with windnoise, I think the wind in the gaps of the panels is also a pretty big factor & a seal at this gap should help a bit... I have considered the possibilities of doing something with the glass, but there aren't really any practical solutions there at all, I guess it get's to a point that it's as good as it's gonna get too, Thanks again

Those door seals can be a huge factor.

**nobb** · 05-23-2007, 06:36 PM

Might I suggest doing a underbody coating as well. I came across this other forum where the guy coated his wheel wells and claimed to notice a huge reduction in road noise.

Btw..Rudy...I love your site =)

**Abmolech** · 05-24-2007, 12:29 AM

I think the wind in the gaps of the panels is also a pretty big factor & a seal at this gap should help a bit

Quite correct. A big factor is the fitment of the panels themselves, ideally they should be level or slightly below (or in) of the panel in front. Two large gains can be made. On the windscreen wipers (presuming they are not below the hood line) suitable after market accessories can help here. The other is the mirrors. The gap that it swivels on is the big culprit, more-so than the cap between the mirror and the door.

Glass, consider another car with double glassing.

**turbocad6** · 05-24-2007, 02:45 PM

I once did the duct tape test, sealing these gaps to see the difference & driving it... theres a big difference with the gaps sealed for sure... cadillac benz lincoln & others have used weatherstripping at the gaps for a while now & I think it helps alot.. the only car I know with the double pane glass is the mid to late 90's benz s class', I do like them but there boxy styling is growing old quickly now that there affordable, & when they still looked sexy they were also a bit out of range $$$

I did half consider doing double pane glass, but the effort it would take would be huge, including recessing the windshield opening quite a bit & pretty radical work on the doors, not to mention the side windows would also take huge efforts.. I dismissed this as being impractical & way beyond the scope of my project...

I didn't even consider the gap in the mirror pivot, makes sense though... I guess one of the best ways to soundproof your ride is replace it with a benz or something

**Defiler** · 05-30-2007, 12:36 PM

You people that claim Peal n seal makes your car small like asphalt in the sun obviously have never used it. My peal n seal install in my current car has been in for over two years and DOES NOT and HAS NOT smelled like asphalt from the second day I installed it.

I even took the door panels off this past weekend to tweak my speakers and it was still stuck in the same place it was when i first installed it, and that was WITH hair pile liquidnailed on top of it.

Stop giving advice on products you've never used. Stop killing the kittens, please.

**Rudy** · 05-30-2007, 04:34 PM

Originally Posted by Defiler

You people that claim Peal n seal makes your car small like asphalt in the sun obviously have never used it. My peal n seal install in my current car has been in for over two years and DOES NOT and HAS NOT smelled like asphalt from the second day I installed it.

I even took the door panels off this past weekend to tweak my speakers and it was still stuck in the same place it was when i first installed it, and that was WITH hair pile liquidnailed on top of it.

Stop giving advice on products you've never used. Stop killing the kittens, please.

OK, folks. Everybody that's had problems with Peel & Seal is wrong. Everybody who's car smelled like asphalt needs to find another explanation for the odor. Peel & Seal worked for Defiler, so you all must be liars or mental defects. I'm sure Defiler also defied the material properties of asphalt and been a really fine sound deadener for Defiler.

Here's the great news. Anbody who follows Defiler's advice and uses Peel & Seal is guaranteed success! If you have any of the problems he has proven to be impossible, he will personally come to your home and FIX YOUR CAR. You can't ask for any more than that folks. Very generous guy. Peel & Seal themselves offer NO warrantee on the use of their product in a car.

Defiler is the man! We'll have to see if his offer applies to all asphalt roofing materials used in cars, or is limited to the Peel & Seal brand. We'll also have to see if his guarantee applies to effectiveness or just product failure.