Like many of you I am familiar with the popular sound deadening 'pads' Dynamat being the most expensive and popular. I spent a couple of hours on the internet researching its competitors and pricing along with customer reviews. Overall, I don't think any of the stuff really works very well. This seems to be proven to me by the audio guys who have tested it with decibel apps on their smart phones. I checked out Dynamat, Noico, Uxcell and half a dozen others and am not really impressed by any of them. There is a product called Mass Loaded Vinyl builders use to sound proof rooms that works very well and wondering if any of the membership has experience with it. It is basically a pretty thick mat that would be difficult to install, does not have self-adhesive and weighs about a pound per square foot. There is a similar automotive product, Damplifier that is adhesive backed but it is much thinner. I'm doing a 1937 LaSalle Coupe and since the body is stripped I want to make the thing as quiet as I can. I recall trying to soundproof a room years ago and discovered that a 1" gap somewhere will allow something like 90% of the sound to enter, so what I'm trying to achieve is a tough climb. Nevertheless, I don't mind the difficulty of installation as I'm expecting the results to be pretty good.
Just a quick answer, I have an appointment, will check back later. I have done 2 off-topic trucks (37 states with a Cummins diesel) and my custom 1962 Volvo. Please consider heat transfer in your planning. Bare body is a great starting point. 1. I sealed my floor with truck bed liner (smooth surface). 2. Go over the whole body, tapping with your knuckle, looking for resonant surfaces. a. If it goes "boing", apply sound deadener (Your choice, I prefer Dynamat xtreme (butyl) over Qmat (Tar based??) for the ability to confirm to curved surfaces). If you have success, the knuckle test will produce a "thunk". b. Next identify the areas that will transfer heat. More to follow - gotta go... Russ
I have heard of it in homebuilding. Maybe This Old House or Fine Homebuilding? Never heard of it used in a car. I think the weight would make it a NOGO?
Dynamat just about everywhere followed by Dynapad on floor, trunk floor, firewall. Cuts out enough of the unwanted noise. In the car I'm thinking of (41 Chevy Coupe) my best improvement came from extending the exhaust to dump out at the rear bumper (previously it ended downward just ahead of the rear axle). What a difference! And the car still had a great sound that I was fearful of losing. Chris
Open to ideas, want to "hear" more Jute padding is effective, I think a lot of people eliminate it once dynamat etc is added. Combo of the 2 would be good. Firewall and exhaust baffling will provide a large sound decrease, look at any new car, stainless waffle baffle between the muffler and floor, often the entire exhaust track. This is both heat and sound deflection away from the cabin. Not many will hang a stainless waffle sheet on the firewall, trans tunnel. But it would be very effective. ( since you mentioned you're up for install difficulty challenges) Muffler placement as far back on the system will also helps with cabin noise. TrailerTrashToo has a very good point. Insulate inside cavities, then also between the interior panel and the cavity to reduce the hollow - echo type drum resonance. I'm sure there's a real term for it.
Carl, I have been using a 3M sound deadener product, part number 08840. It comes in 19"x19" pads with 10 pads to a box and is self sticking. I paid $75 for a box, a heck of a lot cheaper than Dynamat.
On two o/t projects i used butyl based sound deadener, and mass loaded vinyl. I was happy with the results. Used it to replace water sheilds, and on floor with 1/8" closed cell foam (fairly firm) anywhere the vinyl might rattle against something (interior door panel, etc.)
My '37 LaSalle now has a '76 Eldorado engine. My car weighs 3,800 and the Eldo was a ton plus heavier. I think the thicker the better for sound deadening. I am going to use it.
Yes I have and have used it. Works well for sound attenuation. What I have used came in wide rolls. It has a hard, non porous finish and is pliable, to an extent. It works best on flat surfaces. The application that I've use it for was to quiet down screw compressors and the receivers they discharged into. I used it as an underlayment for flooring in bus conversions on several occasions. There are several adhesives recommended for installation, but I have had the best luck with the 3M polyester windshield mastic. It's a bitch to install, you will wish you used Dynamat or a similar product that is self sticking and more flexible
I have ordered another product with self adhesive, but may use the mass vinyl on the floor and firewall and maybe trunk..flat surfaces. I fully understand how difficult it could be to try and apply adhesive to such thick non-pliable stuff.
I asked my interior guy about using it and he said "No way". Carpets are like most else nowadays , not made quite right and with the Mass backing it's way harder to get it to lay correctly. I did one car with Dynamat and agree it's not worth the money. The last car i did i used a product called Siless that i got off of Amazon, it's all the same as long as it's butyl and your'e comparing mils to mils. Use whatever you get the best deal on. That type of product reduces vibration more than silences overall noise. I use Siless ( or whatever) with jute or whatever on top of that. Try to get your carpet without any attached jute if you can, sometimes it's not possible.
IDK anything about the brand you are looking at (or any others for that matter), but I have seen posts on guys using sound deadeners that have melted and made huge messes. You are wise to ask around before sticking it in your car.
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