Jumping in with Both Feet on a 20 Seafari

[Bushwacker]

Originally Posted by SailorChlud

. . . I cannot read the sticker, as some prior owner glued a veneer of plywood over it, and when I took it apart, the glue took off a lot of the numbers.

Is there a way to identify the null number or serial number any other source?

First of all, I don't think there is any wood in the vertical step aft of the bunks that the bulkheads fasten to. It appears to be just fiberglass, maybe about 1/8-3/16" thick. One trick you can use with fiberglass that most folks don't know about, is just to drill and tap it for machine screws! The threads on machine screws aren't nearly as sharp as on self tapping or sheet metal screws, so they don't cut into the glass as bad, which causes the screw to loosen. But I'm not sure this would work in this relatively thin glass because when you get into rough seas where the boat is bouncing around a lot and taking some pretty healthy G loads when it punches into a wave, there can be some twisting loads on the hull that give those bulkheads and screws a pretty good workout! If you drill the holes a little oversize to prevent loading the screws in shear, that would probably help. You'd really prefer to depend on a pure clamping load on the bulkhead to prevent relative motion between it and the hull. Maybe a bit of contact cement would also help!

After one particularly rough Bahamas trip, I noticed the bottom screws coming loose, allowing the bottom of the bulkheads and door frame to shift aft, pinching the door at the bottom. I changed to machine screws & and threaded inserts on the bulkheads as previously described, and also ran a couple of wood screws thru the door frame into the sides of the bunks so they would be loaded in shear, and it's been solid ever since. Another option to threaded inserts for the bulkhead screws is toggle bolts. Although I've bought some from WM that had plastic zip ties running thru a plastic washer that help hold the toggle in place after you insert it, I'd still put a little epoxy on the toggles before installing them to insure they remain stuck to the back side of the fiberglass if you ever have to remove the screws. They're real handy for installing seat pedestals. (You typically have to drill about a 3/8" hole for a 1/4-20 toggle.)

One other thing I'd do to the bulkheads before you install 'em is to saturate the edges and screw holes with some thin epoxy to waterproof them, especially along the bottom. Reason is that it's very hard to seal the bottom edge with caulk, so it's easy for wash down water to get under the edges of the bulkheads, and fresh water will rot 'em out even faster than salt water!

Regarding the hull ID/SN, they didn't start using the hull ID numbers till 1973, so I doubt you'll find any numbers on the transom. I even had to explain that to a young USCG officer one time during an inspection who had never heard that! All you can provide is the hull SN. The numbers are actually stamped into the metallic decal on my boat as I suspect they are on yours, so even if they're smeared over, the imprint should still be there. If you can clean off the crud covering them, you might be able to see them by laying a piece of thin tracing paper over them and rubbing over them with a lead pencil!