: I honestly thought that those kind of things would only very
: slightly effect evaluation of the skin.

Maybe in an objective lab setting you'd be right on the money. But- someone can coat their kayak with varnish and never paddle it and get great durability and give it a high score, but not because the coating and skin combination are great, but because they don't use it. It could be the case that I would take it out once and have to land on a limestone slab with sharp edges in moderate surf, which is not ideal but could happen where I paddle, and I would shred the same coating that got a great rating.

What does that mean? Well- are you going to land your kayak on a limestone slab in the surf? It might not matter to you. It might not matter to me either, if I weren't going to paddle it there, or if I were only going to paddle it there on a calm day. To put it another way- I would not go to the same extent with a child's kayak as I would with a kayak I would for myself, and I wouldn't use the same coating for a rolling-only kayak as I would for a paddling kayak.

I'd keep a few things in mind, like- always make sure that your coating is as flexible or more flexible than your fabric, or it will probably crack sooner or later. Always make sure your coating will stick to your fabric, or it will have adhesion problems and probably delaminate. With the skin, are you more concerned with abrasion, or puncture resistance? Are you willing to accept puckering, or do you want a skin that is always tight? Or in the case of canvas- do you want it to get tighter when it gets wet? Each also has aesthetic concerns. I'd make a matrix and evaluate it that way.

My concern is- I can't imagine how I would rate any of the options realistically unless I knew what I was going to use it for. I'm not saying that I wouldn't give it a numeric score, I just think it would be hard. So- I'm hoping to finish one, maybe two SOF kayaks by fall, and here's what I'm going to do. One for my daughter will be covered in 8-oz polyester (because someone I know had a remanent that was the right size) and Rustoleum Marine Topsides paint (because I have some already). It's perfect for its intended use- durable and since it will only be used a few years and sparingly at that- cheap. I plan to build a historic replica, and spend a lot of time making the skin look like the original, which I visited in its museum. I plan to use either 12 or 16 oz polyester, and Coelan Marine Coating. In both of those cases, I'd give them a really high rating. But- I have used 8 oz nylon and Corey's goop, and I would give that a moderate-to-low rating, depending on what qualities are important to you.

I'm not trying to duck your original plan- I want to help. I just couldn't think of how I could do it within the parameters you set out.

m