Observer Seat Rebuild

I had posted about redoing my observer seats a while back here... got a few more questions.

1. The small seat looks like it has plastic film between the foam and the wood. Was it from the factory like this? The plastic wasnt on the large seat over the cooler, just this small corner seat bottom. Maybe the large seat was recovered and they left out the plastic film... not sure.

2. Peter suggested that I use exterior ply with CEPS. The CPES is pretty expensive. I can buy a 4x8x1/2 pressure treated ply for about $25. Would it be ok to use treated ply instead of exterior ply/CPES?

Here is a pic of the small corner seat bottom with the plastic sticking out.

Kirk - Due to an unfortunate accident, I need to create the observer seat base from scratch. Can you provide the width & length measurements for me? I have a new skin but was going to guess at the base size. Also a photo of the edge construction would be very helpful too.

I am just going to use exterior plywood coated with some epoxy resin, thinned with xylol (home brew CPES).

SNobsessed wrote: Kirk - Due to an unfortunate accident, I need to create the observer seat base from scratch. Can you provide the width & length measurements for me? I have a new skin but was going to guess at the base size. Also a photo of the edge construction would be very helpful too. I am just going to use exterior plywood coated with some epoxy resin, thinned with xylol (home brew CPES).

Chris my 89 seat bases are a plastic type material not timber. This is the bottom of the upholstered cushion not the plastic roto-cast base with the cooler. The material is the same as used on the bases of the seat cushions on my 98 Sport. Will get a picture of the base with dimensions for you.

With pt materials you need to use either hot dipped galvi or stainless steal fasteners. So that means stainless staples for fastening the skins. The pt these days are caustic and will case the fasteners to fail quickly.

TR - My '89 has rotocast bases.

Chris, I'm sure you could call Christines and get an idea, and possibly pictures, of the foam you need (density, dimensions, etc.).

when doing the cpes home brew..you need to add the hardener to the epoxy resin and then mix it up with the xylene?

kapla wrote: when doing the cpes home brew..you need to add the hardener to the epoxy resin and then mix it up with the xylene?

Seb,
I would reduce both the resin and the hardner and then mix the two. It will just give you some added pot life.

Kirk,
I do not know what you are reading but CPES does not have a 40 hr. pot life. I go by it since I do not advocate the "home brew". You start screwing with chemistry that you are not qualified to do and you may end up with results that will screw you in the end. Are these documents you are reading written by qualified chemist's or just some junk you found on line?

Pete,
I hear what you are saying.. the website I was reading is

http://www.epoxyproducts.com/penetrating4u.html

I just ended up using 1/2 PT plywood. I got a 2x4 piece which was enought to do both the corner seat and the observer seat for about $10. Lowes has some stainless staples for $10 too. That was cheaper than buying the chemicals.

Here's a pic of the observer seat before I put the skin back on it. Before I put the skin back on, I put some 2mil plastic between the skin and the foam (like the original)to keep the foam from getting soaked.

I used some #6 deck screws and waterproof glue to put the wood together.

Both seats turned out great.

The plastic film is an upholsterers trick, the foam is very "grippy" against the back of the vinyl fabric, the plastic allows the surfaces to slide making it easier to pull the cover into place. You can use dry cleaner bags as a substitute.

+1 on the plastic and the electric knife Dave. The problem with the knife is getting it out of the kitchen and back without the Mrs knowing

Kirk - Just got caught up on this thread, been missing it for some reason.   Thanks for the observers seat plans, just what I needed. I think I will also use PT ply.      I can't see it ever rotting out with the usage we will give it.    I need to get started on this project!

Tim Benj - I suggest polypropylene plastic for a never-rot seat base.   You can staple straight into it.     You just have to figure out a way to get it in the thickness & shape you want.

I finished my replacement observer seat cushion today.

A big thanks to Kirk (Karther) for the base drawing, & Dave (OverMyHead) for the electric knife tip.

Projects like these would not be practical for me without the great advice from you guys, at least with any respectable outcome.

Here are some photos.

I used exterior plywood for the structure, coated with homeade CPES. I had some epoxy at the end of it's shelf life, so it only cost me $5 for the xylol. The thinned epoxy soaked in well. I used 5-minute epoxy adhesive & finish nails to secure the joints.

I used some repurposed foam from an old matress. (new foam is surprisingly expensive) This was the hard part, creating the foam shape from scratch.

The electric knife left rough scallops at the contoured edges, which I was sure would telegraph through the skin.

I wrapped the contoured pieces with 1/2 inch sheet foam to hide the scallops. This resulted in an overstuffed condition, but at least I didn't get wrinkles.   I had to glue the foam together, as it kept bunching up when I went to put the skin on.

One lesson learned is that the softness of the cushion changed quite a bit after I streched the skin & stapled it down. I thought it was going to be softer than original (with the extra foam), but it ended up a little firmer.

Thanks again to all your help & have a safe New Years Eve!