Technical Building wood seat base webbing vs sofa springs

Pick your foam from an upholstery supply. They can guide you on what you can use because they deal with auto upholstery shops almost daily.

 

The upholstery shop I use suggested ditching the stock springs and build a wood base for my '40's seat bottom using plywood for the lower and upper forms, with 2 x 4"s split diagonally to create the stock rise. Two different density foams were then used to get the stock seat height, and feel I wanted, then final covering was applied. I left the "open/webbing" option for later if needed, but so far the seat has been very comfortable for several thousand miles, with no changes planed.

 

here is the underside of the modified VW bug rear seat bottom cushion. The zig zag springs are also at the front wall of the seat as well as short ones at the rear of the tapered cushion assembly.

So the springs are also forming the entire shape of the cushion and that enabled the whole thing to have a cushion effect.

I'm 155lbs and this is so much better than a cushion I made from just a 5" thick block of foam years ago on a different car, and no matter what density of foam, it won't feel like this.

I can see that I used a thin sheet of softer foam over the springs, then covered that with cotton batting made for quilting. (And a very thin layer of foam for sewing the roll and pleats into the seat cover.)

In a perfect world we could go to a wrecking yard and sit in a bunch of seats with our own body weight, and then copy how that best feeling seat is made with the same materials.

Middle pic is trying to show the front wall of the cushion and how the factory shaped and bent the zig zag springs so that they can compress.

Last pic is trying to show that the very back wall is also made that way, but the cushion is very wedged shaped and it's hard to see how they did it

 

Thank you! How thick is the front and rear of the cushion?

 

Shit, I'm too tired to go out to measure today. Let's guess for now at maybe 8" to 12" tall at front, but extremely tapered towards the rear, which seems to work well with the fixed backrest angle of the 31 Cadillac seat wooden framework.

I think, or I would bet, that a person's weight should be considered, rather than copying any seat shown here. I should ask my son who has driven it on long trips too, he's well over 6 feet and 220 lbs or more.

I only showed this because you asked about those zig zag springs. Plus I realized that sometimes our homemade cushions made from just foam, can't compete with factory engineers that can start with a clean slate.

 

I should have also said that this cushion does not sit on the floor. It fits into the wooden framework of the Cadillac seat which is raised above the floor for it's seat adjuster mechanism.

I can get back out there tomorrow to measure the total height with cushion installed and a pic. The car was a 32 5 window, now a conversion to a fake cabriolet with a 40 Ford dash, and I and several other much taller people fit in there just fine. So it relates to your 5 window somewhat.

 

I am working on a 32 roadster. I want to keep the stock riser etc. I am 200 lbs.
Thank you

 

My mistake, I saw the blue coupe. Anyways, my riser looks about the same height, but my entire seat framing is on a adjustable track.

That seat adjustment seems to be a must have for mine because I run the seat all the way ahead and my son runs it all the way back. It's a standard shift and these cars are so cramped for foot room near the relocation of the column, when operating the clutch and brake pedals.