So I'd like to blame the PO for putting down tar and roofing paper to the floor but that was me about 24 years ago . Grinded away most of the stuff but would like to know what to do with the floor before adding the sticky sound deadner-prime?paint? some kind of sealer? Attached are some pics of the floor as well as when it was first restored. Doesn't look as good now but I'm getting there. This MAW project started simply by wanting to paint the arm rest..... Thanks for any input.

 

Good to know I'm not the only one.

Normally, I'd say strip it and paint with POR-15 or equivalent before the Dynamat, but you've got a LOT of work with a heat gun, scraper, and lacquer thinner to clean that mess. Frankly, the floors don't look bad in the photos. You might want to just close your eyes, stick down the deadener, and quickly install carpeting before you change your mind...

 

I would tend to go with Joe on it. He is a wealth of experience and advise. I am about to get started on my interior as well. Has anyone ever used regular foil wrap insulation fron Lowes/Home Depot instead of the Dynamat?

 

If you can afford it Dynamat is a way to go. I also used Lizard skin with success, not as good as Dynamat but when installed with GM repop under carpet sound deadener (OPGI) it was just as good.

 

I suspect he'd need to get all that remaining tar off the floor before using Lizard Skin, unfortunately.

 

It actually looks a little better in person but sad to say that condition is after several hours of grinding. Floors are pretty solid. I plan on using the Home Depot stuff for cost purposes, do you think I should put it on bare metal? Or put some kind of coating on it. Dont think POR is in the budget. Thanks for the feedback.

 

From what I was told the hardware store version of dynamat will work well for sound but on hot days especially with darker interior you will smell the tar/asphalt.

 

I would at least prime the bare metal.

 

X2. Slop on some Rustoleum at a minimum.

 

Can I spray rustoleum to bare metal or do I have to prime first. Thanks

Based on the below link I'm hoping the HoDo stuff does not smell.

https://classicoldsmobile.com/forums...tml#post487628

 

That stuff looks like it will work well for heat transfer but doesn't look it will do much for sound. The stuff I was talking about looks like dynamat. Foil with a thin layer of asphalt. It will block the sound but like I said it will start to smell.

 

Frankly, I'd just use Rustoleum primer and call it a day.

 

Exactly. It's the layers of different density materials that blocks the sound. We went through a very similar process trying to find materials to block launch acoustic inputs on a space launch vehicle.

 

Thanks for the feedback!

 

Clean, degrease, paint.
Make sure the surface is 100% dry. Even condensation on the surface will prevent adhesion. My garage propane heater caused issues. I used fatmat, heated it the oven to about 140 degrees. It REALLY sticks then and also conforms to every bend.
High density material like fatmat, dynamat is great for sound. Both external sound and resonance of metal panels. The low density, foil, reflexit, is good for temp insulation.

 

Just like Gary, I used FATMAT less expensive than Dynamat. You do not have to cover the entire floorpan with the FATMAT/Dynamat for it to be effective. Over my FATMAT I used EZ cool.

http://www.lobucrod.com/

Good luck

 

The comment on here regarding layers as most effective for sound deadening is correct. There is even a fella that has a patent on a method of sound damping for speaker enclosures that involves an initial layer having more transfer followed by a layer that has less, followed by one that is most dense. The practice is to trap the sound for the greatest effect. Once sounds have gradually passed through the more transparent layers it has to pass through them a second time on the way back creating the greatest elimination of sound.

 

"We went through a very similar process trying to find materials to block launch acoustic inputs on a space launch vehicle."

So you are a rocket scientist!

 

I had used some spray on undercoating on the floor pan years ago. When I cleaned it to install fatmat it was very difficult to remove. I shot it with some brake clean and it melted the tar-like substance so well that I could wipe it away quickly and easily.

 

I used the Insulation from Home Depot. My floors were in good condition but had been previously sprayed with undercoating. I used high tack contact cement to adhere the insulation to the floor. It shaped to the contours of the floor very well. I also installed an extra jute pad under the carpet. I was very happy with the results.



[IMG]URL=http://s1310.photobucket.com/user/Stephen_Sampson/media/Mobile%20Uploads/2014-02/IMG_20140208_110541819_zps8inh0gf7.jpg.html][/URL][/IMG]

 

My Miata is super loud from road noise. I used Dynamat in the trunk, door skins, floor. It helped with road and engine noise, a lot. The Miata is super thin skinned, so any vibration is taken up in the skin, increasing the noise. The Dynamat works by basically adding weight to the skin, which cuts down on the vibration (noise) that skin can create. I also put Dynamat in the trunk and floor of my Olds, not sure how much it helped since I did it before putting the engine in and driving it. You don't need to do the whole door skin, just some of it to add weight to the skin to cut down the vibration.

There are different manufacturers of that type of product, the cheaper stuff (like Noico) uses asphalt based (tar) - you can smell it. Dynamat Extreme is butyl rubber, thicker than most products.

 

I went the Lowe's/Home Depot route and am quite happy with it. My floor pans were fine so I didn't do anything to them......

A few pics from my adventure..

https://classicoldsmobile.com/forums...adener-124472/

Cheers,

Troy

 

I’m currently using Fatmat to line my car. It’s working out well. One question, should I cover the holes in the partition that separates the back seat from the trunk? —Billy

 

No one answered you
What did you end up doing?
Getting ready to do mine
Any tips appreciated

 

Do you mean something similar to these areas highlighted below?

 

Yes, exactly
Can you just put a solid piece across all of that?

 

You can put strips of Dynamat or equivalent on the metal braces to reduce vibration noises but the large openings would not benefit from it. Some years had a cardboard layer between the metal and the seat back. In the '80s there was a very thick blanket of jute with a layer of tar that was used for soundproofing. A cardboard/jute barrier would be easy enough to fabricate. If you are going for a complete resto, best to research what came factory on your year.

 

Just to chime in on an old thread. I Dynamatted both of my ‘66 big car floor pans from firewall to trailing trunk edge. Total overkill at 100% admittedly.I also scraped and Dynamatted the underside of the roof of my ‘66 Starfire coupe. The next layer under my carpet in the convertible is jute, if I recall. That same middle layer between carpet and Dynamat in my Starfire is Dynaliner as I recall. I even laid Dynamat on most of my Starfire rear wheel wells.

Not the cheapest solution, but I have a thing about noise, so I’m happy with the spend.

My Starfire has a jute “rug” behind the backseat isolating the cabin from the trunk. It’s cheap and works fine, but you have to make a bunch of cuts to allow seat retention bracket and what not to protrude and do their job. Also shoving thick material in there that GM didn’t intend in 1966 means getting seats back in can be a minor challenge…

Another thing that helps reduce noise is closed cell foam underneath your door panels and underneath your rear quarter panels. I use 1/4” thick closed cell foam with an aluminum backing to replace the tarpaper GM used in 1966 works great. In my door and quarter voids, I double layer the foam to have yet more insulation since the stuff is light weight. All this material is kept in place by interior spray glue which gets messy over the years but works fine.

The end of this road is getting your door & window seals really right but that’s another topic. Let’s just say you can burn days & days on making old cars quiet. As long as it’s fun, carry on. When it becomes a chore, live with the fact that standards were different then and you have a cool old car.

Chris