Anyone have any luck firming up their original seat?

[Maximus]

Like the title implies, I was wondering if anyone has firmed up their original seat during a upholstery job?
My original seat only has a couple tears, the frame itself is pretty solid but the springs are too dang soft. When I sit on the seat I drop like 5 inches into the seat, theres no support. My old 87' f250 had a nice firm seat but my truck is so original I would really like to avoid replacing it. I was going to bring the seat to a local upholsterer but before I did that I thought I would ask around to see if anyone had any tricks to firm up the seat? If it comes down to it, I may just source an 80's bench and have it upholstered similar to my stock bench...

[sargentrs]

I'm no expert and have never actually done it but as I'm stripping my Mustang buckets, I can see how I'd do it. I'd take some wire about the size of a wire coat hanger and weave it front to back through the curves of the springs, wrapping the ends around the front and rear frame rods. Then hog ring it to the springs at the center and split the difference between center and front, then rear, and hog ring there too. Another hog ring to secure to the front and rear support rods. Maybe run two more full length side to side and secure those with more hog rings. Then top it off with new foam. I think that would more than double the support.

[72BahamaBlue]

Years ago I got tired of the sag, so when I had the seat out I tied all driver's side springs together with heavy nylon cord, wrapped around each s-loop and connected it to the next row...made a web. It did firm it up.
You could also add more springs from another seat, from the less used passenger side. I did that on my dentside seat, there was just enough room to add a few rows between the existing ones, secured the ends of each to the frame and kinda stapled them together with heavy wire. If it's really sacked out, replace the old springs too.
You might also look for a different type of lining to cover the springs, that burlap doesn't hold up very well.

[CharlaineC]

You can start firming it by looking at the foam you use when building your new seat. you can use a firmer foam under the couch foam. Then you can add more springs either from another seat or you can buy them. Weave heavy nylon cord across the the whole bench. The next thing you can do is add a couch stiffener across the springs. Its a rigged nylon board that goes over the springs.

[robroy]

Good day Maximus,

I hired Palo Alto Upholstery to re-do my original bench seat based on Dentside-era foam. They had to cut a custom plywood base to make it work, since the Bumpside-era seat frame didn't have the right kind of support.

The seat feels great, and my head hits the headliner a lot less often when driving over speed bumps now; the factory springs can have quite a bounce to them.

Unfortunately, I didn't take photos of the plywood base the shop made.

Here's a photo of me sitting in the seat. I weigh 265 pounds, and you can see that it holds me up just fine. IMG_5561x.JPG.

Robroy