[jpd37]

My old '37 Plymouth has a bench seat that has been reupholstered. The springs and frame have been covered with stiff foam and the springs are all in good condition. What recommendations are there that I could employ to reduce the springy softness of the seat?

[Max Keith]

Remove your upholstery and foam, get a ball of spring twine from any uphosltery equipment out let.
Measure your seat front to rear and divide it into fourths, marking it with chalk.
Tie the spring twine to the center chalk mark on one side, and using half hitch knots, tie the line across the springs, being sure to keep the spacing between the springs the same as it is at the anchoring points on the rails. Repeat the process for the second and third lines.
If your springs already have new twine strung through them, yo could simply thread more through by running them between every other set of ties. The more ties you have the stiffer the seat will be.
To test for firmness, lay the foam back on the frame, and toss a blanket over it, and sit on it for a few minutes to determine whether you have the correct stiffness you want. If its too stiff, remove the twine and divide the seat into thirds and repeat the process. To stiffen it more, divide the seat into fifths. You can also use this process to stiffen up the back cushion as well, however, you shouldnt need to make them quite as stiff as the back doesnt hold as much weight as does the seat cushion. Simply deviding the back into thirds should be plenty stiff.
While you are at it, you might want to make sure that all the springs are properly anchored to the frame work.
IF you have coil springs rather than zig zag springs, the tying of coil springs is a lot more complicated process, and I would recommend you take the seat to a competent upholsterer to have that done, as properly tying coil springs can get you very confused, and there are so many combinations of ways of tying them.

[snkbyt]

Check out my car pics in the journal. I stuff the springs with foam chunks then put the pad on top, sit in it. If not stiff enough I put more foam stuffing in the spring centers til it reals right. To contour the seat you can also tie down the center springs and leave the outers untied to your liking.

[jpd37]

Thanks for the tips. I have the coil spring architecture, so I'm going to try Snkbyt Method first. The coils are accessible from the bottom. I'll get some semi-dense foam and see what happens.