Seat bottom material or "What's it made of?"

HDPE, at least for my driver seat. I don't think any glue will stick to it.

Post a picture, maybe you have something else.

Theres some stuff called pro poly thats made by innerduct for glueing HDPE conduits and couplings together, that will tear the couplings apart before the glue fails. Don't know if it would be acceptable for gluing a seat back together or not, but its one of the only adhesives that will glue HPDE to HPDE. Short of that you need to plastic weld it together using HPDE rods.

I agree up to now, but TAP plastics poly-weld adhesive will repair or even build HDPE pieces together. You can watch one of their many informative videos on their web site.

Yes that is my understanding (all seat bases have been xpvc since wood was eliminated).

X = expanded

Sorry, didn't pickup about bases vs seat bottoms.

I was referring to the driver seat bottom, which is a thick amber plastic on my boat.

The seat "base" is what the foam sits on and the vinyl is stapled to. CC went to composite in '93. Ive been told that its been XPVC ever since. No idea what the rotomolded driver's bucket is made out of, nor the plastic seat frames used on late delux 2001's (or 90+ NWZ rear seats for that matter). Calling those piece "bases" is probably misleading- frame is probably a better term. They did take the place of the aluminum frames used previously, after all.

Chris, now Im confused even more- what piece of your driver's seat is made of thick amber plastic? The base? The rotomolded bucket? The pedestal? The base should be plywood (as was my '90), and the pedestal is gelcoated fiberglass. If your base is plastic, then my bet is that its not original.

harddock wrote: Would 3M 5200 silicon do the repair?

Kevin,
5200 is a moisture cure polyurethane!!

It's 2013. Pics would really help. The seat "base" threads are always a mess.

Chris, Ive been gathering information as of late (mostly from Christine's) about composite seat bases for the '80. Turns out CC has used XPVC (Sintra Board is the specific brand) since they went composite in '93. There are some tricks to working with it, but Im determined to not use ply!

Im sure its the same stuff they used on the trunk floor in the Crush. We have a piece or 2 thats shattered pretty good (held together by the carpet)... maybe from running a bit of weight back there?    It sure doesnt look repairable- at least I wouldnt expect it to hold any weight afterwards. For boards that dont need to hold staples, coosa is probably a better choice. Otherwise, thicknesses should be chosen carefully and strategically placed reinforcements should be added, especially for wider spans.

FYI: I am pretty sure after all the input here and my own research, the material is in fact expanded pvc sheet. About .50 inch thick. I found one or two suppliers online that will sell special cuts so you do not have to buy an entire sheet. Interstate Plastics having most any type of synthetic sheet/material made.

However, I ended up dismantling observer's seat bottom and repairing the cracked xpvc-sheet on both sides with "Aero Marine" two-part epoxy resin I have used their epoxy many times repairing boats and other items. If you have any rotten wood you can restore the rot with their resin and wood-dust as a thickener. Old or new wood can be "sealed" with their resin thinned with no more than 10%, by weight or volume, acetone then saturate wood with the mixture and it will encapsulate the wood fibers (penetrating resin) to prevent future rot.

On this job I added a thickener (cabosil)to part-1, to make a paste then added hardener (part-2)and "glued" the two edges together, then used the regular two part resin & fiberglass cloth on both sides (one side at a time)to cover the break. Once cured it was much stronger than original sheet. If it breaks again it will be in another area. Plastic welding was also an option but cost for buying the welding-tool and repair material would have exceed buying an entire new piece of XPVC or other synthetic sheet in the size I needed.

Hi, thanks for the reply but your reply goes beyond the subject post.

1. I recommend "Aero Marine" products, I have plenty of experience repair to boats and other things and have found nothing better to work with. Their epoxy resin is non-blushing and Low VOC. That is all I was saying.
2. You are making presumptions/assumptions that go beyond what I stated in my post. It merely stated Aero Marine products if used properly are excellent, including their use for repairs to wood-rot. Nothing was stated on "best practices" or "how to" properly repair wood rot in a boat. This depends on a case by case basis and depends on exactly what it is you are trying to repair.
3. I was not speaking to repair of wood rot in my post.

Regards, Monty