Technical Let's talk about seat foam

I am getting close to doing the seats in the roadster. I am having a hard time figuring out what foam to use. It seems to me that there isn't a standard across the foam world.

I am familiar with aircraft foam and there is a standard for the different foams. They color code the foam, based on the density. I just don't wanna pay for aircraft foam. It's stupid money. You pay for the certifications.

In the aircraft world they start with a firm foam for a base, then a medium firmness then the soft on top. Glue it all together, then they carve it.

I am trying to figure out how to do the same for the roadster. The only foam around here is for mattresses. Not even sure what to search for on the web.

Let's talk.

 

Stuff ain’t cheap.
One place (don’t know the name) sent samples. Different densities.

google automotive seat foam

if there’s an upholstery supply place near ya, go visit.

 

Watching this thread too as I was wondering the same thing!!

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Done it. Been researching for weeks. It's a rabbit hole.

 

My mattress is just one piece of foam and damn is it the most comfortable one i’ve had. I don't remember if it’s what’s called memory foam or not. I would consider buying a small mattress to use. Something like this from Lowes

 

I sent my Corvette seats to Tijuana , They are pretty comfortable and don't smell like horse shit. Sorry Chris couldn't resist

 

Well, that's a good thing...

 

Have you asked @HomemadeHardtop57

 

We had a short discussion on another thread.

I have been looking at these folks foam. Not sure on what thickness I should start with.
https://www.yourautotrim.com/3hashfo.html
https://www.yourautotrim.com/55x82hiqufos.html

 

These guys have a broad selection. Got the foam for my 41 Plymouth from them.

https://rochfordsupply.com/shop/CushionCraftFoam/index.html

 

Wayfair has memory foam mattresses from anywhere between $ 118,, to $ 200 for a regular size mattress,,,,,and go up to $300 and more .
A nice 10 inch mattress was about $140,,,,I believe a man could get several seats out of that .
You could shop and see,,,,,different thickness,,,different firmness .
It’s just an idea .

Tommy

 

All I have to offer is a thought process. Are you using springs too? Let's say yes. If so, spring base 1st (easier than it sounds) then something firm, closed cell about 1 inch or so. Spreads the load. Next something softer, a little thicker and when the cover goes over that you'll pull it down to the final hgt. This gives a seat that holds you in place without being sloppy and springs assure long life.
If no springs, all foam, you need a heavy dense base for support and strength then softer for seating surface. Source not often thought of? Packing companies. The places they send things usually scrap the foam blocks after time. I've scored enough "come n get it" foam to build a cpl seats and if you weren't so far away I'd say drop in and let's build one.

 

I went to pick n pull for my last seat base. Found the newest car took the backseat out narrowed etc. I have a fried in the upholstery business. Foam for cars is stupid money. Lust like the aircraft foam different densities, glued carved etc. Or find a seat bottom, new foam replacements with durafoam then narrow and reshape for what you are using it on.

 

I bet Jim can tell us exactly what you need to know. Hey @stanlow69

 

The subject of foam for seats is definitely a rabbit hole and I really wish we could get some experienced upholstery people here who could advise us on the right foams and sources for them.

I’ve asked the same question here before and was underwhelmed by the responses.
With the number of experienced upholstery members we have responding to the upholstery threads it’s amazing that we can’t seem to get good information on seat foams and construction/ sources.

 

This is out of a company in Chicago I used to buy from. Study this.

 

What I do. I go by what engineers have spent years researching and designing the shape of foam seats for automobiles for years. So I use what they know and get foam from used seats. If they have 100 thousand miles on them and are not destroyed. It must be good foam. A little repair might be needed to make the seats as good as new. Use the passenger side foam for the drivers side. If possible. When looking at a new piece of new foam, (compared to wood) can you tell if it`s a piece of Walnut, of if it`s a piece of Pine. How long is it gonna last ?

 

Go to craigslist, free section, look for memory foam mattresses and sofas, harvest n hault the rest to the dump. Its work and dirty but cheap as hell!

 

Foam in couch cushions are way too soft and have no firmness as compared to auto motive foam. That`s why furniture is so cheap. They use cheap foam that does not last. That`s why it is difficult to know if a new piece of foam is worth a darn.

 

Years ago ,I use to buy cheap foam mattresses just for the foam, and I use to carve them with an electric bread knife.

Tip : always carve / shape the underside and let the top sides roll around the shape,
If you must shape the top /outer edges ,glue a layer of 3/4"-1" foam around it [or it will appear lumpy]

If you are putting foam directly onto a piece of ply [with no springs] put a layer of 1" polystyrene on the bottom.
Your spine will thank you.

I've built seats for off-road racers with 6" of foam that still "bottomed out" .so the poly fixed that issue. [like a helmet]

 

Buying used mattresses off of Market place is not something I would want to use. No matter how good the foam is. Yick !

 

Thanks for the replies.

A couple of things.
We tried memory foam in our aircraft and all of the pilots complained that the seats were too rigid. We ended up replacing all of it.

Next thing is, we do have springs in our seat frames. I had Wise Guys build us a set of frames to fit the openings since the car was channeled and had the drive shaft tunnel to contend with.

My thing is I don’t know what is a standard thickness. 4” ? 3”? How much does it compress over time? I don’t want my covers to get loose in a month of driving.

Jim, I will take a look at your info when I can see it better. I have old man eyes and I am looking at my phone.

 

This explains it much better. But to get this info on foam you are buying is the tricky part. The support factor, firmness and the density are what you want to know for good long lasting comfortable foam. And always buy the best. Don`t buy foam at fabric stores.

 

We had one custom built seat that used trampoline mesh/mat/whatever it’s called as the “springs”

 

If you live near a city, look up foam suppliers in the area. I worked at a place that used different types of foam, and sometimes I had to go to one of our suppliers. They took me around and showed me what was available.

 

I`m sure there are different grades of memory foam as well. Putting burlap over the springs isn`t enough. You need to put a topper on it, or you will be able to feel the springs thru the foam. I use household bonded carpet pad foam. There are different grades of that as well. I always use this when a board is the base as well.

 

I was taught to use 46 ILD (1.8) for the seating, and 70 ILD (1.8) for the bolsters if you’re custom sculpting the foam on a wood base. Keyston Brothers is a good supplier.

 

Ford pickup`s used that for the seats for a couple years. I can post pic`s if anybody wants to see examples of anything I posted already. When putting foam directly over the burlap, springs, seat frame, glue some good material on the bottom side of the foam. The seat frame (ect...) will cut into the foam and break it down. Just look at your daily driver.