Effective sound proofing trick.

[Buffalohed 10+ year member]

If anyone has seen my previous posts/threads on sound deadening you know I am somewhat obsessive about it. I have tried and experimented with **** near everything to further quiet my car, and am always trying new things.

Anyway, the most recent mini-project I did made the biggest difference since I first deadened the front doors.

I have a bucket of butyl/asphalt roof flashing cement which I coated the outer rear wheel wells with about 1/4-1/2 inch of. Now it is a messy process, I got the stuff all over my hands/arms and some on my car, but that is because I'm sloppy. I also used the same stuff in the trunk.

It smells for a couple days but boy it made a huge!!! difference in road noise. Almost all of the noise in my car now comes from my engine and the windows. I can't attest to the longevity of this treatment, it's only been a few days, but reapplying it should be no problem if it melts off or something (mine is tested to 250 degrees).

It's real cheap, takes maybe 30 minutes, and is hugely effective. Next I am going to do my front wheel wells. By the way, it is much easier if you jack up the car a few inches near the wheel you are working on, gives you more room to work.

//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

***PICS***

I told you it was a messy job //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

And here is the inside of my rear door, just for the hell of it. It looks like ****, but it works!

Click to read more...

 

[Dozy_production 10+ year member]

how much would it weigh down the car.

 

[Raven 10+ year member]

Good find. That would make for some extra weight though. I'd guess 30 to 40 pounds all said and done.

 

[Buffalohed 10+ year member]

No way dudes. Entire bucket is 30lbs, I used maybe 1/15th of it for this. I'm only talking about the wheel well on the outside of the car, as in the part of the car that is surrounding the tire. Weighs next to nothing at all, but it absorbs a shitload of the noise coming off the tires at the closest point for it to enter the car.

Now I am going to eventually use the entire bucket on the underbody and fill in some more places in the trunk, but that is because I'm crazy //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

PS - I had previously tried the rubber spray coating you can get at Autozone for this. Used 3 cans, $6 each, and it didn't do ****. You would need like 20 cans to get the same thickness as 10$ worth of flashing cement.

 

[Raven 10+ year member]

Interesting! Now, being in Texas you wouldn't have this problem, but I wonder if that could have a positive or negative impact towards rust on the underbody? My Taurus has some crazy road noise but it's just not a good enough vehicle to justify the cost of real deadener. I may test this idea within the next few days.

EDIT: Also, at my local NAPA, that spray rubber stuff is $2 / can. Great for sealing enclosures IMO.

 

[conecommander 10+ year member]

Interesting! Now, being in Texas you wouldn't have this problem, but I wonder if that could have a positive or negative impact towards rust on the underbody? My Taurus has some crazy road noise but it's just not a good enough vehicle to justify the cost of real deadener. I may test this idea within the next few days.
EDIT: Also, at my local NAPA, that spray rubber stuff is $2 / can. Great for sealing enclosures IMO.

Be sure to let us know what results you have, as I'm interested in this as well. Maybe even throw up some pictures of the process.

 

[genxx 10+ year member]

Interesting. Buffalohed let me know how it holds up this summer. I am about 30-45min north of Austin. I know the summer can get hot as hell. What is composition after it dries. Is it hard or still have a little softness to it. You have me interested to see how this works out. If this does not melt and get all over the truck this may be one the best finds. I would love to get rid of some road noise. Thanks for the test and post.

 

[traksta15 10+ year member]

where can you buy it?

 

[corto 10+ year member]

sounds good

 

[audioholic 5,000+ posts]

For road noise, you'll have much more effect by adding absorption layers to the inside of the car (closed cell foam, carpet backing, etc) than you will slopping stuff on the outside. But yeah, if you really want to coat the outside (alot of people do), that stuff probably works fine. But for god's sake, don't ever put it inside the car. Just use concrete if you want an effective mass loader.

Let me know if you want my concrete recipe.

 

[Buffalohed 10+ year member]

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

There are many different kinds of flashing cement you will find at Lowes/Home Depot in the roofing department, you should look through them to find their temperature ratings and different properties. I got the kind that has butyl rubber in it. 30lb bucket was ~$30 for the middle-end brand, cheapo stuff is less.

When it "dries" it is still pliable. Kind of like tar but not super sticky. I highly doubt that it will actually melt even in the summer here, but I will let you all know if it does. The good thing is if it does melt, it has nowhere to go but to run down the inside of the wheel well (where it already is anyway) and then drip onto the ground, so no harm done.

As for deadening the inside being more effective, I can't comment on that. I heavily deadened the floor of the car before doing this, but like I said I noticed a bigger change with simply coating the tire wells than from deadening the entire inner floor.

I wouldn't recommend putting it inside the car... no, however, I do have a ton of it in my trunk. It hasn't caused me any problems after 3 months.

 

[genxx 10+ year member]

Buffalohed- You have no problems inside the car because the fumes are making you high from driving around.//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

But you know I am just kidding with you.//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif I just could not help myself.

I do want to try this out so keep updating this thread please. Thanks Brian

 

[audioholic 5,000+ posts]

As for deadening the inside being more effective, I can't comment on that. I heavily deadened the floor of the car before doing this, but like I said I noticed a bigger change with simply coating the tire wells than from deadening the entire inner floor.

Did you apply closed cell foam, carpet backing or similar to your floor, or just mat? Ive found mat isn't the most effective at blocking/absorbing road noise, even when done thoroughly. It helps, but not dramatically. The foam works MUCH better than mat does. I also like using expanding foam to fill body panel cavities (plus concrete), but that's going too far for alot of people.

Are your wheelwells plastic or metal? Keep us posted how this stuff works out. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Bloodstalker999 10+ year member]

How about some pictures of the application? This sounds like something worth doing

 

[Buffalohed 10+ year member]

Did you apply closed cell foam, carpet backing or similar to your floor, or just mat? Ive found mat isn't the most effective at blocking/absorbing road noise, even when done thoroughly. It helps, but not dramatically. The foam works MUCH better than mat does. I also like using expanding foam to fill body panel cavities (plus concrete), but that's going too far for alot of people.
Are your wheelwells plastic or metal? Keep us posted how this stuff works out. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

3-4 layers of raamat where the floor is thin, 3 layers of ensolite everywhere, and some pink insulation foam (not the fiberglass stuff) that I had laying around. To be honest I was pretty disappointed with the results of floor deadening, which I did about a week after the trunk and doors.

I haven't really seen any body cavities that I could fill with foam. Maybe I just don't know where to look //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

The wheelwells are really flimsy plastic behind the wheel, but above and forward of the wheel it is metal with some kind of plastic coating. I also tried to get as much up around the brakes/axle assembly above the tire as possible, without actually getting it on the parts of course.