Sealant for cloth parts of collapsable kayaks?

A co-worker is helping build collapsable kayaks for his boyscout troup.  They're planning to use latex paint to seal the wood and cloth parts, I suggested upgrading to polyester resin for the wood (same price, higher durability) but I don't know what would work better than latex paint for the cloth.  There must be something though!

What have the other boat-builders here used or heard of being used?

You could search the baidarka mailing list archives:
http://robroy.dyndns.info/baidarka/

I do know that latex paint is old school. People are now using sealants designed for this specific application.

Thomas Yost has some fairly cool designs that use aluminum, UHMW polyethylene and PVC coated fabric.
http://www.yostwerks.com/

And then there are always the classic books by Robert Morris and Christopher Cunningham on skin on frame kayak building.


Regards,
Scott