foam thickness

[Belairmike]

What thickness foam would you use for the front seat backrests on a 55 chevy? Also what density are firmness . Mike

[ahkahn]

Thickness is whatever the job calls for.  I would measure the thickest part (unless you want to glue) and get some foam that thick.  As for density and firmness, that's completely up to you.

Density:  How "good" of foam are you looking for.  Is this foam that will be sat on daily or once in a while?  Is this foam that will be expected to hold it's shape for 2 years or 20 years?  All of those questions dictate density.  If it's a cushion that will NEVER be sat on (maybe once in a while) you can get away with a lower density foam (1.5-1.8).  If it's a daily driver and you're doing a driver's seat, I would get a very dense foam.  Most common is in the 1.8-2.6 lb. range.

Firmness:  Strictly personal preference.  If you want it to sit like a brick, get a firm foam.  If you want it to sit like a fluffy couch, get a very soft foam.  Everyone will have an opinion on this, but we're debating chocolate or vanilla.  Most people use a 45-50 IFD.

-Andrew

[ThrowMeAPillow]

it's been ten days and you have probably moved on, but 20 lb is probably as firm as you would go on any back foam.  You apply surprisingly little pressure when you lean back.