Foam rubber seats

[JimS]

Hello to everyone. We have an 05, thirty foot Classic with slideout. Great trailer. We enjoy boondocking and have spent time at the Grand Canyon, Bryce Canyon, and anyplace else we can get to when we are off work. We have been enjoying the forum and have learned a lot from everyone. I am sorry to hear that David Tidmore left Roger Williams Airstream. We have had great service from them, and hope to use them in the future.
We are having a bit of a problem with our dinette seats. The foam rubber flattens within about five minutes of sitting. The plywood below is not that comfortable! The foam rubber is grey and moderately dense. I am wondering what grade of foam rubber (or if there is an alternative) to replace it.

[moosetags]

We're glad to have you here with us.

We have an '05 25FB, and have the same problem with our dinette seats. I have also been consideing replaing the seat cushion foam with something better. I am also anxious to hear the answers.

I had not heard That David Tidmore had left Roger Williams. Where did he go?

Brian

[65CV]

Jim-

That doesn't sound like foam rubber, it's most likely polyurethane foam. The key to getting good quality polyurethane foam is to get a high density. With the cost of oil rising, the higher density foam is getting more expensive.

When you get a replacement, think about something like an 1835 foam. The first two numbers are the density -- 1.8 pounds per cubic foot. The second two are the firmness. The 35 is the number of pounds of resistance the foam gives when compressed by a standard 10" diameter plate. Practically, if you are under 200 pounds, it's about right. Hopefully your distributor will have samples to try out if you want softer or firmer grades.

Foam rubber is made of latex, either from the rubber tree or synthetic or often both. It's about 3 times the weight and more costly. It was used by Airstream in the '60s in a layered sandwich with polyurethane foam.

John

[JimS]

Thanks for the info on the 1835 polyurethane, I am checking it out. Will let you know about the results. Being a polyurethane novice, I also wonder what weight and density Airstream put in their seats. Thanks for the information.

[vswingfield]

Another possibility is to put a layer of denser foam at the bottom and softer foam on top, sort of a dual-zone approach.

[65CV]

The firmness and density can be varied independently in polyurethane foam. I'd stick with the higher density for longevity.

The soft / firm layers are a good idea. You could do something like an 1821 on top and an 1835 on the bottom. If your distributor carries the 26 density, you could upgrade to that for an even longer lasting product.

Latex foam rubber gets denser as the cushion gets firmer. It's heavier, more costly but longer lasting. Just the last two numbers are used to grade firmness in latex foam.

[2airishuman]

Originally Posted by JimS

... The foam rubber flattens within about five minutes of sitting. The plywood below is not that comfortable!...

hi jim IF this is a classic model dinette, there ISN'T any plywood under the seat cushions...

the seat should have a frame supported metal perimeter tube, with convoluted flat metal springs under the cushions.

these dinettes did NOT come with hard flat seat bottoms, unless that's a unique feature in slide models.

the springs CAN sink if the sitter is...really heavy.

and standing on the seat bottoms can alter the spring supports negatively.

DOES your unit have the originals as described, or has someone ALTERED this dinette, with plywood flats?

i can post photos of the oem dinette, but it would be more useful for u to post a pix of the seat bottoms in your trailer.

cheers
2air'

[JimS]

You are correct. It is not plywood under the seats, it is the convoluted flat metal springs. It only feels like plywood after the cushion flattens out! Neither my wife of myself are that heavy (160's), so, I suspect that a less dense grade of polyurathane was used. Thanks

[2airishuman]

ok, jim now we're on the same page.

i've fiddled with the dinette and tried different bolsters UNDER the upholstered cushions.

finally settled on covering the oem seat bottom with another 2 inch thick layer that protects the fabric and cushions the tush...

like the cushions available for wood rocking chairs.

because of the under spring support design, new foam would need to be THICKER and denser,

which would not fit inside the oem fabric covers...

dacron/poly batting OVER the foam (like on the sofa) would work nicely too.

there are several lengthy threads on the anatomy of foam...

http://www.airforums.com/forums/f46/...oam-17503.html

http://www.airforums.com/forums/f46/...oam-22151.html

http://www.airforums.com/forums/f39/...use-24305.html

http://www.airforums.com/forums/f39/...ion-28985.html


cheers
2air'

[vswingfield]

A lot of auto upholstery uses the soft/firm approach. (thanks for that term, 65CV) The soft part is usually thin while the firm creates the shape, the foundation.