Sound deadening the Cruiser (1 Viewer)
- Thread starter MrOffshore
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
the key to good adhesion with any of this stuff is liberal use of the heat gun.
Quality sound damping material doesn't need a heat gun to adhere. I've never used one, never needed to. Closest I've come was an electric heater on an extension cord to warm up the cab, and that was because it was like 40* out!
I also keep hearing scaremongering of roofing products failing and smelling when used as sound insulation. But none of these stories are first hand, they are all from people who used other products because they heard something, or even worse, people selling other products.
I'm looking to find anyone who has used asphalt/bitumen based products and had it let go or melt into a heap. Anyone out there? Kevin's fatmat story is the first, but I'm not quite sure from his story where he had it installed or how hot he thinks it got.
I've just used a "modified bitumen" product through the floor of my work car (which incidently does have asphalt/bitumen based deadeners from the factory). There is no smell or volatiles, not even a hint of a smell when the backing is peeled and the whole surface exposed. When laid down only the edges are exposed. Add up the whole area of exposed edging and tell me how that compares to the roads we drive over.
Last edited:
I've never used it, but I've been in vehicles where it has been used. And every single time I've been able to smell it. Correlation, not causation, but....
It's not even close to being the same.
Roads aren't enclosed, in an essentially sealed environment. As soon as they get hot enough for the asphalt to become volatile, the wind blows the gasses away.
Plus they rarely get hot enough to even get to that point. For the majority of the US, you're talking maybe a month or two where for a relatively small portion of the day they get that hot?
OTOH vehicles are quite enclosed and pretty much sealed. Even on a relatively cool day, a closed up vehicle can get hot enough to make asphalt based products soften. And that gas isn't being pushed away by anything, instead it's building up inside the cab with no where to go (except your lungs when you get inside).
And, FWIW, road asphalt fumes is considered potentially dangerous for your health, and there's been some push on stricter requirements for road crews who work around it (right now there's no exposure limits). While I'm far from one to jump on the "CANCER!" bandwagon, I have no doubt that it can't be good for your health.
Why needlessly expose yourself to something that's very likely harmful to you, when for only a bit more you can something that's basically completely inert? Would you use lead based paint because you're not very likely to get sick from it and it's cheaper?
Vehicles aren't sealed either, if they were you would rapidly pass out from your own CO2 production when inside.
How hot is hot enough? Put a figure on it.
Tarmac here melts in summer.
Comparatively, they are.
Interestingly enough, I've found in a couple different vehicle manufacturers users manuals (such as an older Toyota Tercel) have instructions on how often (and how long) to switch to fresh when running recirc. The reason given was that running recirc for prolonged periods of time could cause drowsiness, dizziness, light headedness....any of this ringing a bell?
The thing about vehicles is they tend to trap stuff in there. Else carbon monoxide poisoning wouldn't be so much a concern.
There's not really a figure for when asphalt becomes volatile, because it's comprised of many different components, and they all have different melting/boiling points.
However, house roofing can out gas, and they typically max out temps in the 150* to 160* range. This obviously drastically reduces the life of the roof, which is why many roofing companies are switching to butyl based products in hot climates.
It doesn't take much to get a vehicle up to 150*. My UltraGauge has alarmed (180*) from my truck sitting in the sun all day on a fairly mild temp day (early summer).
So any way you cut it, a closed up vehicle can easily reach temps high enough to make asphalt volatile.
I've used it, the floors were fine, but most of the sides and roof fell off when it got hot. I didnt notice any vapors, but the car I did it in is pretty open.
A couple of comments from a guy that sound-deadens autos a lot (note: I did not say 'soundproof').. For those with a hefty wallet, ok you can Dynomat the truck. But to do this right, it's a lot of square feet, and the bang4buck quotient is really low, comparatively speaking. It also tends to block only low resonance noise, which I think is addressed pretty well on the 80. IME, it's the mid and mid-high frequency noise that's at issue. Roofing tar inside the vehicle is generally considered a no-no, but can be fume 'set' by spraying black rustoleum paint on it after it cures. I use rubberized roofing tar on vehicles, just not inside the cabin.
When I went thru my 10 different exhaust systems, I also went after sound deadening. My favorite product for that is 3M Silencer strips (3M 08585) 3"x50'. It's a butyl rubber product that is very effective at reducing noise by 'mass' = lowering the resonance of a given metal panel. Years ago, I used it between the hood frame of my turbo 4runner, and it will survive upside down indefinitely. On my 80 I just did the tailgate a couple weeks ago (I'll get a pic and post it), and the difference was significant. I also had a spare can of rubberized undercoating (3M 08883) from a previous job, and sprayed the wheel wells and body/frame behind the right rear wheel, and above the spare tire. Also noticeable.
I also removed the biggest drum in the 80 - the right side plastic panel covering the PS rear wheel. I added several sections of the 3m Silencer strips to the body, and to the plastic panel itself. Also made a big difference, especially in the rain.
Back to roofing tar. First you want the rubberized/plastic type if you can get it. The best place for it is in the wheel wells, above the spare tire, on the frame, and on the DS floor pan underneath (I don't do ashphalt based above the exhaust for all the obvious reasons)..
Bottom Line: 3M Silencer Strips and rubber undercoating products used correctly, lower the med/high resonant frequencies better than 'mat' products IME. In addressing *any* sound-deadening, don't forget the outside of the truck is a great place to start. FYI, the box stores also sell Butyl based caulk that has a really high bang for buck factor.
Final thought: IME the 2 main factors for wanting 'additional' sound-deadening are tire noise and exhaust. The best bang for buck for tire noise is addressing the wheel well, inside and out. The best bang for buck in addressing exhaust, is the exhaust itself. If you spend your money here first, supplemental sound deadening can be done effectively for under 100bucks.
HTH and my .02
Scott J
94 FZJ80 Supercharged and selectively 3M'd
When I went thru my 10 different exhaust systems, I also went after sound deadening. My favorite product for that is 3M Silencer strips (3M 08585) 3"x50'. It's a butyl rubber product that is very effective at reducing noise by 'mass' = lowering the resonance of a given metal panel. Years ago, I used it between the hood frame of my turbo 4runner, and it will survive upside down indefinitely. On my 80 I just did the tailgate a couple weeks ago (I'll get a pic and post it), and the difference was significant. I also had a spare can of rubberized undercoating (3M 08883) from a previous job, and sprayed the wheel wells and body/frame behind the right rear wheel, and above the spare tire. Also noticeable.
I also removed the biggest drum in the 80 - the right side plastic panel covering the PS rear wheel. I added several sections of the 3m Silencer strips to the body, and to the plastic panel itself. Also made a big difference, especially in the rain.
Back to roofing tar. First you want the rubberized/plastic type if you can get it. The best place for it is in the wheel wells, above the spare tire, on the frame, and on the DS floor pan underneath (I don't do ashphalt based above the exhaust for all the obvious reasons)..
Bottom Line: 3M Silencer Strips and rubber undercoating products used correctly, lower the med/high resonant frequencies better than 'mat' products IME. In addressing *any* sound-deadening, don't forget the outside of the truck is a great place to start. FYI, the box stores also sell Butyl based caulk that has a really high bang for buck factor.
Final thought: IME the 2 main factors for wanting 'additional' sound-deadening are tire noise and exhaust. The best bang for buck for tire noise is addressing the wheel well, inside and out. The best bang for buck in addressing exhaust, is the exhaust itself. If you spend your money here first, supplemental sound deadening can be done effectively for under 100bucks.
HTH and my .02
Scott J
94 FZJ80 Supercharged and selectively 3M'd
SUMOTOY: do the 3M silencer strips have an aluminum face, and about how thick are they? The price per square foot looks like maybe 30% less than the Dynamat sold at Best-Buy (best price I found). For the 3M rubberized undercoating, how thick did you spray it, multiple coats, or asking it the other way, about how much did one can cover??
Adding to the discussion of how well some mats stick or dont, even in 50 degree weather Dynamat Xtreme sticks very aggressively. I wanted to reposition a small 3x3 inch piece seconds after it just lightly touched the metal panel, hadn't pressed it into place yet, and had to work at it to get that small piece to come back up.
Adding to the discussion of how well some mats stick or dont, even in 50 degree weather Dynamat Xtreme sticks very aggressively. I wanted to reposition a small 3x3 inch piece seconds after it just lightly touched the metal panel, hadn't pressed it into place yet, and had to work at it to get that small piece to come back up.
Last edited:
Comparatively, they are.
Interestingly enough, I've found in a couple different vehicle manufacturers users manuals (such as an older Toyota Tercel) have instructions on how often (and how long) to switch to fresh when running recirc. The reason given was that running recirc for prolonged periods of time could cause drowsiness, dizziness, light headedness....any of this ringing a bell?
The thing about vehicles is they tend to trap stuff in there. Else carbon monoxide poisoning wouldn't be so much a concern.
Who runs with their heater on recirc? Recirc is only for short term "not breathing that smelly stuff we just drove through".
I once borrowed a car (used for short trips around a city) where the heater was stuck on recirc and the owner didn't know. The whole car interior was seriously damp and took a lot of long driving to dry out.
But anyway.
I work in metric (I'm not in the US), 150F, that's about 65C. Anything left in the sun here can reach that temp on a good day. Leave a chromed spanner lying in the sun and you can't pick it up in summer.
180F, that's a hair over 80C. I'm pretty sure my black house roof will get near that, but this house roof doesn't have any tar/asphalt/bitumen products in it. It certainly gets hotter than shiney stuff does.
Gahi said:
Great, found a user. So which brand of stuff did you use and was there any smell when installing it?
For the record I'm not in the US, I'm using a different product, different brand and sold in a different country. The stuff I used is also foil backed tape type and the core is listed as "modified bitumen" in the data sheets. It has no smell at all. I even peeled a fresh piece yesterday to check.
If I get organised I might do a melting point check on it in the future.
Last edited:
I used Grace Ice & Water shield. It was leftovers from the local roofing company. It was free so we gave it a shot.
From the GRACE site:
"Grace Ice & Water Shield and Grace Select are cold applied, self-adhering membranes composed of a high strength polyethylene film coated on one side with a layer of rubberized asphalt adhesive and interwound with a disposable release sheet. An embossed, slip resistant surface is provided on the polyethylene"
3M silencer strips are Mass density deadening, not really meant for 'total' coverage ala dynomat, it's designed to change the resonant frequency of a panel (like what the 80 has stock in the doors and PS rear quarter panel. A 50 foot strip box is plenty, if well placed about the 80, and will have better bang for buck than dynomat IME.
3M comes with a wax paper like backing, and the rubber is a bit over 1/8in thick. WRT the 3M spray, once I open the can, I tend to use it all. 1 can will cover the rear wheel wells, frame and over spare tire panel with at least 1 coat. I did a couple coats above the rear exhaust resonator.
I also noticed a difference in resonance of the exhaust by removing the rear resonator>frame bracket, and installing a rubber pad between the bracket and the frame. One of the biggest contributors of noise is exhaust hanging hardware, especially in the back. The standard issue exhaust shop stuff can be brutal, causing you to spend more in 'mat' than it would have to just use a good oem exhaust hanger.
Many folks just add dynomat, but bang4 buck that is really low. The first thing is to figure out 'what' noise you are trying to address. IME, automotive noise vibration and harshness (NVH) addresses are specific to the source you are trying to tame. In my case, it was exhaust as the primary, wet weather tire noise secondary. That really does not dicatate a dynomat solution.
HTH and my .02
Scott J
94 FZJ80 Supercharged and 3M'd with Dodge SRT8 rear exhaust hanger
SUMOTOY: wish I had known about the 3M silencer strips sooner, only thing I could find locally was Dynamat Xtreme. FWIW, while I was working on the driver's door with the engine running I noticed a fair amount of noise (and heat) coming out of the front DS fender from the engine compartment, it blasts out hitting the front of the door itself. That's got to set up vibrations in the door that get retransmitted into the cabin, like a drum IMHO. To help address that when I applied the Dynamat to the exterior door panel I also put some short strips on the inside front of the door frame, in the general area where the wiring harness comes into the door, as well as some on the inside rear of the door frame, below the electric door lock mechanism. Might have overdone it a bit, but I wanted at least the driver's door as quiet as possible.
Last edited:
About 10 years ago, I used an array of Cascade Audio sound control stuff on a minivan.
I used mostly the VB-2, and the liquid VB-1 (applied with paint brush) on the inner hard-to-reach panels.
Worked out really well, and no bad tar stench. I’ll probably do the same to the LC at some point.
Automotive Noise Control - Soundproofing
I used mostly the VB-2, and the liquid VB-1 (applied with paint brush) on the inner hard-to-reach panels.
Worked out really well, and no bad tar stench. I’ll probably do the same to the LC at some point.
Automotive Noise Control - Soundproofing
jjfj80
SILVER Star
The factory sound deadener IS asphalt based. There's a factory
TSB comparing the 90-91 models that mentions this.
TSB comparing the 90-91 models that mentions this.
gahi said:
Just a fyi, IIRC, there is a "Grace" premium product as well, that is butyl based (no asphalt). They were right next to each other at Home Depot, when I looked a while ago.
Sent from my DROIDX using Forum Runner
Right, I saw that when looking at their site. They also have a HT High temp that the adhesive is rated to 240 degrees.
Any info from 3M on installation guildlines on silencer strips?
Seems like $42 a roll is the going price?
Seems like $42 a roll is the going price?
