Seat Rails - On top of carpet?

[Cutlass]

It's time to install insulation, carpet and seat rails. I'll bet that the factory placed the rails on top of the tar paper, then cut the jute and carpet around the rails. Anyway, it makes sense to me to fasten the rails directly to the floor pan, with no insulation or carpet between the rails and the floor, although it could be done the other way, I guess. Is there a preferred method?

 

[Dave Russell]

There were originally also steel base plates on top of the paper & under the wood spacers. About 1/16" thick, 2" wide & slightly longer than the wood. Not many vendors show these plates/shims.

As you describe, these plates, wood spacers, & seat rails were on top of the paper. The jute & carpet were cut out closely around the slides to permit removal if they got wet. Imagine that!

If by chance you were adding extra heat barrier to the floors, it should go right next to the tar paper, or in place of it, under the slides. Else there won't be room for the slides to clear the floor coverings.
D

 

[Cutlass]

Makes sense, Dave. I did know about the steel and wood spacers, and made them myself using the old rotten and rusted ones as patterns. Not to change the subject of the thread, but do you have the latest opinion on insulation? Eastwood is running a special on what appears to be a Dynamat substitute called Hushmat. It's cheaper than Dynamat, and purports to have thermal insulation qualities.

 

[Dave Russell]

Several years ago I used the heavy foil "Dynamat Xtreme" in place of the tar paper. I like it because of the very tough sticky Butyl adhesive. When properly rolled down over a clean surface, no danger of water ever getting "under" it. Many other kinds use a lesser adhesive.

If you don't wish it to show, it can easily be overpainted to match the car color.

It always amazes me how much work & money someone will put into a car & then look for the cheapest stuff for this job.

I guess that's why everything imaginable has been used.
D

 

[Cutlass]

Thanks, Dave. I'm not looking for the cheapest alternative here. My biggest concern is with the thermal qualities of the various materials. It's been discussed ad nauseum in other threads. This new material promotes its thermal qualities, while Dynamat seems to just mention them in passing. I have yet to see actual R values on either.

 

[Dave Russell]

I suspect that lots of materials will work. I tightly rolled down two layers of Dynamat, inside & outside. Maybe over kill, but the interior surfaces are always cool to the touch.

Under the carpets is a thin closed cell foam in place of the jute. No water retention.

Since I never want water trapped under the insulation, I consider the quality of the adhesive to be very important.

I have seen a lot of old cars with more rust on the inside than on the outside.

I'm sure you will be happy with whatever you choose.
D

 

[John_Progess]

Dave,
Am I to assume that you put two layers of Dynamat on the inside and outside of the floor pans and then installed foam inside and then the carpets? Then did the wood spacers for the seat rails go ontop of the foam? Is there a need to paint this stuff as it is under the carpet? Thanks and have a good day!

John

 

[Dave Russell]

Dave,
Am I to assume that you put two layers of Dynamat on the inside and outside of the floor pans and then installed foam inside and then the carpets? Then did the wood spacers for the seat rails go ontop of the foam? Is there a need to paint this stuff as it is under the carpet? Thanks and have a good day!
John

Hi John,
Yes, two layers of Dynamat on each side, all vertical & horizontal surfaces. All overpainted body color. The paint helps seal any gaps in the Dyna joints to keep water out & gives a uniform appearance to the floors.

The closed cell foam was only loosely laid under the horizontal floor surfaces of the carpet which are removable & retained with snaps. It just gives a bit of cusion feel to the floors. No foam under the spacers, seat areas, & vertical surfaces.

The engine compartment has all surfaces over painted, no white asbestos board showing. I've read that some original cars also had the asbestos over painted so I don't feel too bad about the departure from originality. I've noticed that the original white gets pretty dingy after a few years of use. To paint or not would be your choice.

Couple of pics attached.
D

 

[Cutlass]

Dave: Can you describe the closed cell foam you used? I found a self adhesive, dense foam with applied aluminum HVAV insulation, about 1/4 inch thick, at our local builder's supply that might be a good product for some applications. I placed some on the inside of the firewall, inside the cockpit, assuming that it would do better than Dynamat at insulating. Also placed some inside the doors for sound dampening, and the effect is quite good.

 

[Dave Russell]

I used this:
https://tinyurl.com/5gtxtp

Volara 1/4" 2# Closed Cell Foam Padding
Volara is a fine closed cell gaming table foam which has a a very low water absorption rate and does not remain compressed. This is the highest quality padding available for game tables. It is 48 inches wide and is sold by the running foot.

I suspect it's available at other places.
D

 

[Cutlass]

Thanks so much.

 

[TodE]

Dave,
I have a couple questions. Where can you buy the plates? Were they on all models 100 - 3000? How did you hold the foam down?

Thank you in advance,
Tod

 

[Cutlass]

The plates are quite easy to make. They are just plain steel, about 1/16 inch thick and about 1 1/4 - 1 1/2 inch wide with appropriate holes drilled to accommodate the seat nuts.

 

[Dave Russell]

Hi Tod,
As I said above;
"The closed cell foam was only loosely laid under the horizontal floor surfaces of the carpet which are removable & retained with snaps. It just gives a bit of cusion feel to the floors. No foam under the spacers, seat areas, & vertical surfaces."

If you choose to do it differently, "3M Trim Adhesive" might work.
D