The epoxy is Polycon 77 with the Polycon 22 hardener. The resin and TATA are made by Ciba-Geigy (which also makes several of the West's System epoxies). The accelerator (the stuff added to "trap" unbonded amines in the resin mix versus at the surface) is made by Monsanto. All pretty much standard stuff which is found in other epoxies. The kayak is my first, my first love, and it's made with the very same epoxy and glass, and survived three honking big waves on 31 May 2002 commencing at 15:23:22 PST (check my first couple postings way back when). This is a retrofit to install a heavy rear bulkhead of 1/4 inch plywood angled to allow it to be a back rest. Also, solid walnut cheek plates were made to be a lock cable area, hip area for rolls, and to be a backband attachment area (walnut pices were soaked in alcohol bath several days to remove the oils, then air dried a week in the garage).

The first inkling that something wasn't right was when a plywood panel was laminated with 3.2 oz triaxial glass and 2-inch tape, 42 hours later both peeled right off. The wet-out was done in a heated garage in warm weather in San Diego (garage temp 75). Both resin and hardener were warm and the mix is a 3:1 by volume, 1.5 oz to 0.5 oz, stirred for about 5 or so minutes while soaking up the warm sun in the morning. Thorough mix I let the mix sit while I cut the 2 inch tape. Surface prep was 60 grain sandpaper. Painted on the epoxy using a fresh chip brush, then pulled the tape slowly through the epoxy to wet it out, then laid it in place, using brush to dab smooth, ends to push against wood. The 3.2 oz was laid on clean, dry virgin plywood rear bulkhead, wet out with the brush, and allowed to sit as I made up some coffe, then returning, used the spatula to draw excess epoxy off leaving a wet, shiny coating. The ply went into the oven prewarmed to 140, heaqt off, the ply was set in and allowed to sit the rest of the day, then before Rikki came home, I set it outside in the sun. That night it sat next to the yak to cure. The next day I ran around to get ready for Florida, that night I had a chance to mess with the ply and found the glass hadn't stuck. Checked the tape and sure enough, it peeled with a easy tug. Getting back, I burned a copy of the images and conditions onto a CD, gave Yale a copy and after some talk, they suspected the hardener. So, they gave me a 2 gallon supply of new batch resin (CG), and two different hardeners, one with the Monsanto accelerator (Polycon 22) and hardener (CG) from a new batch, and a new hardner from Dow without the accelerator (Dow, "955").
Recent layups ALL didin't work, using 3:1 as directed, with the same glasses I've always used on all four yaks, and the same paranoid and careful layup process, talking to myself throughout the process. Total failures though the epoxy set hard as hell. Also, surface prep was scrubbing with hot water and fresh scrub pad, two fresh water rinses, dried and sanded with 60 grain, then washed with SLX alcohol, then allowed to dry and warm.

Now I'm thinking to epoxy in 4 mahogany blocks sanded to fit the shape of the hull at each point where the cheek plate contacts the hull in order to eliminate the glass and have a monolithic support piece with corresponding increase in epoxied contact area. I'm just waiting for the alcohol wiped area to dry before going to it. For the aft side of the rear bulkhead, I'm thinking to use a potting compound along the edge for the rear bulkhead to press against. The stuff is a viscous black plastic goo that sets up in 5 minutes (3M), has strength and some give. Obviously I'm not relying on the epoxied and glassed areas no longer, and want to put my faith in a back-up plan, too.