Using ABS Plastic Sheet & Insulation For Firewall Insulation '37 LaSalle

[carlhungness]

  I believe a repro firewall insulation pad for my '37 LaSalle costs about $325. To the best of my knowledge they are made of ABS plastic and I don't know what type of insulation they have. One can order the part with or without holes.
  What do you think my chances are of fabricating one myself, using ABS sheeting and one of the many insulation materials that are available. I sure don't need all the holes as I'm not using the stock coil and possibly a few other things. I DO have the old original that appears to be made from Masonite and puffy insulation. In fact, it is nearly restorable, but has a rip or two that would be hard to cover up.

[Moody]

ABS is pretty forgiving stuff. With a heat gun, and some patience, you should be able to form it to work well. Jute insulation would work on the firewall side. After it gets close to the correct shape, a little heat gun work could fine tune the fit during trial fitting. Just form it over your existing pad.
Dave

[carlhungness]

    I have never worked, or even held a sheet of ABS, but I do like the idea of using a heat gun. The stuff is really pretty inexpensive and I feel confident that I could do a pretty professional looking job.
   As far as 'jute' or other insulating material, one can get a headache from researching modern insulation materials for old cars, hot rods, etc. I'm really not sure what to put on the floor-boards or in the doors at this point.
   Thanks for the heat gun tip..I will buy a sheet and post my experience.

[cadillac ken]

ABS is a great material. In the cars I build I always pattern out the old door panels in ABS. Most all OEM door panels are only a slight bit better than cardboard from the factory.   The ABS takes the pop in door panel clips without ripping out when the door panel has to come off down the line.  I have also used it as a tack strip replacement for headliners as it takes staples really well.  And as mentioned a heat gun will shape it nicely.  I use the 1/8" for the door panels and 1/4" for a tackstrip.

The jute you want Carl is the stuff most upholstery suppliers sell as underlayment for carpet.  It's a masticated multi-color gray looking stuff and is about 1/2" thick.  You can try Albright Supply.  They have a website.

For my '37 I used the 1/2" thick dynamat type product that is self stick under my carpet and on the interior firewall.  Works well and stays put.  Easy to cut and you can carefully piece and seam it together where necessary.  Both a sound deadening and an insulating advantage.

Cheers, Ken

[carlhungness]

   Thanks Ken...can you suggest a supplier for the ABS you buy...I am finding that some call it 'plastic'..and want to make sure I get the right stuff. I'll get both the 1/8th and 1/4 as suggested.
    The dynamat has great reviews, is pretty pricey too, so now researching what to use. I'll try the Albright Supply for the underlayment.
    It sure helps to have someone who has experience in these 'new' to me things I'm trying.

[Tom Beaver]

Carl, since the firewall pad is a flat sheet I got a sheet of the door panel material and used my old firewall pad to cut out a replacement.  I then bonded a sheet of rigid polyurethane foam to the back of the new pad with epoxy and then painted the pad to something that approximated the proper color.  I then covered the inside of the firewall on the car with foil faced insulation and attached the new pad with washer head screws like the original.  It was much cheaper than the commercial pads and I could control which penetrations through the pad I wanted.  Here is a picture.

Tom Beaver

[Abe Lugo]

Carl
Check for an local upholstery  supply shop.  See if they have the jute with foil backing  by the yard.  Usually about. 5-10 bucks a yard.  You prob only need two yards .  This what I'm using instead of the more expensive stuff on the firewall.  You can either spray glue or use those firewall through button holders.

[cadillac ken]

Hi Carl:  I'm lucky to have a "plastics" supplier right here in town (actually right down the street from my shop!) but if you find a Lucite, Plexiglass place you will most likely be able to get the ABS from them. ABS is ABS.  I don't think you can go wrong when ordering it if it is explicitly ABS (Acrylonitrile Butadiene Styrene). 

Good Luck, Ken