recovering seat - vapor barrier?

[halz426]

I got some tack strips to finally reupolster my seat tonight.

My question is: Should I install a vapor barrier under my seat cover too protect the foam.

I had thought about using thick plastic, but im not sure its necessary.

thanks in advance....

 

[BigD_83]

I am not an expert in this area, but (I think) the original seats did not have a vapour barrier, and are open to air through holes in the seat pan.

The new cover itself should be waterproof, unless you are going with some sort of loose-weave fabric.

I would think a plastic layer between the foam and cover would cause the cover to slide around a little.

Let's see some pics of your upholstery...

 

[halz426]

Yea, it has the holes on the bottom of the pan. I bought a pitman replica cover. Ill try n get pics up after work. Thx

 

[Gorminrider]

I think I can confirm what BigD83 said. I've re-covered two originals and no vapour barrier seen. The originals were waterproof covered.

 

[chuck hahn]

All the ones I have taken covers off had a thin plastic between the foam and cover. I think it has at least two .

First it helps the cover slide against the foam during shifting of seat position and simply just mounting the bike.

Second, I think it acts as a water barrier should the cover be saturated to the point water can leak thru. Lets the foam stay dry and not act like a giant sponge that takes weeks to dry and get full of mold in the process.

I cover the entire foam with contact cement after I have cut a contractors bag to fit the foam. Coat the foam and let it set up and do the same with the plastic bag. Line it all up and lay the plastic over it all.

 

[BigD_83]

That's interesting, Chuck. I've not seen that on any of the bikes I have worked with, so I'll have to keep an eye on the 650 cover when I pull it off. I can't see anything under the cover where the rips are (hence pulling the cover to have a new one made), but that doesn't mean there isn't one there.

 

[Guest]

There was one on my '79 parts bike. It didn't do much to protect the pan from rust. I never bothered putting one back on.

 

[Gorminrider]

... I do remember one or two short strips of 1+1/2" wide brownish scotch-type packing tape,originally stuck to the foam but the glue was on it was powder...
I've not yet seen a ripped seat in a scrapyard (or craigslist!) with anything identifiable. It might have had someting to do with the cushioning imprint patterned in.

If the cover has any stitched seams across the seat, I'd probably put something on.
and, I put a piece of garbage bag under a home made attempt at a cover because I don't trust my stitching, but BigD83's idea of slippage and whatever bad effect it might have did not occur to me at the time....

 

[Crankthat]

I would think that a plastic cover may cause the foam to retain moisture and cause rust on the pan.
Though a reg seat may cause the same effect?
Time working in a ice plant I learned a few things.
The better quality ice bags breathe.
This allows vapor to escape so they do not look like crap during shipment to the ice machines outside stores.
If a bag hits the ground we threw it away.

Possibly call local ice plant and see If they use this type of bag.
Would keep seat dry but allow vapor to disperse.

 

[GSJim]

My 650 has the original seat cover directly on the foam, no plastic. However the original cover has a thin layer of foam sandwiched between vinyl and a plastic layer that has mostly rotted. The replacment cover from Saddlemen is just vinyl and foam.

Jim

 

[chuck hahn]

I havent seen the plastic go under the seat foam between the foam and pan ever. The foams I have taken off have always been glued directly to the pans. And it usually the side toward the frame thats the most rusted .

 

[halz426]

Thanks for the replies, I wasn't sure. I figured since I had it apart I might as well do it right.

I had thought about just covering the top & sides of the foam, leaving the bottom open to breath.

My concern was about maintaining the original foam and not getting a wet ass.

So the foam is supposed to be glued to the pan? When I took my seat apart the foam was just resting on the pan, but a PO had it apart before me.

 

[Gorminrider]

So the foam is supposed to be glued to the pan? When I took my seat apart the foam was just resting on the pan, but a PO had it apart before me.

answer is Yes.

There's quite a lot on the web about seat re-covering

start here
check out Bass Cliff's site,

look for and download pdfs "Seat Cover Replacement" on the left side.

http://members.dslextreme.com/users/bikecliff/


and here's another one
http://cxgl.wikispaces.com/How+to+Rebuild+and+Upholster+your+Bike%27s+Seat

 

[Steve]

Time working in a ice plant I learned a few things.
The better quality ice bags breathe.
This allows vapor to escape so they do not look like crap during shipment to the ice machines outside stores.
If a bag hits the ground we threw it away.

Possibly call local ice plant and see If they use this type of bag.
Would keep seat dry but allow vapor to disperse.

Or, you could just get a bag of ice and not throw it away.

.

 

[Crankthat]

Or, you could just get a bag of ice and not throw it away.

.

Not all bags are the same.
We have stores around here that fill their own.
The vapor escape bags are more expensive.
Not everyone uses them.
You would want to make sure you are getting the correct part
Then buy your bag of ice and keep the bag.