This has been a great conversation, and we've probably all learned something from it. I'm the last guy to argue that our cool little creations don't deserve anything but the best, but there's a concept called "close enough for KR work", and it involves not going way over the top to get things done, either in the money department or the effort (and time) department. Before I spent a lot for the top-of-the-line spar varnish for the inside of my airplane, I'd consider the laminating epoxy that I already have on hand.
N891JF had no epoxy, urethane, or varnish of any kind inside the cabin. I guess the assumption was that it was going to live in a hangar so it wouldn't be a problem, or maybe it was a weight concern. Since I have it stripped down to nothing but wood inside, I figure it's a great time to coat it with something, especially since I've seen N56ML with large ponds of water in the back due to thunderstorms at OSH and SnF. So I ran over all the bare wood with a palm sander, vacuumed it, and mixed up about 4 ounces of epoxy. I thinned it a little with lacquer thinner and applied one good coat to all the wood surfaces, plywood and spruce, in the cabin, from the backside of the firewall up to the seat back. That's all sides, floor, and spars. I figure another 4 ounces will easily cover the rest of the fuselage including tail cone area. So I've used what might be a dollar's worth of epoxy, which I had on hand already, and might have thrown out in a few years because it had turned brown and worried me. Great place for old epoxy! I'm sure this is not what you'd want to do for maximum life of a boat hull, but for the occasional KR puddle, this is "good enough for KR work", and it cost me a half a pound for some long-term insurance. I have to admit though, the thing looked perfect in bare wood, over 25 years after construction! When I do the back, I'll do what's recommended in the plans and in general wooden aircraft lore, which is drill a 1/8" hole at the aft two corners of each floor "compartment" (where the water is going to collect), and then epoxy that area and seal the edges of those holes. This will allow any water that collects to drain harmlessly to the outside. The tri-gear strategy is probably the front corners, rather than the aft corners. Good conversations about any KR building or flying is always construction and welcome... Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
