H25 sole
(Ed-- I was on vacation.)
I did this horrid little task first-off when I got my '74 boat. Truly it was the reason the PO abandoned it. Turns out (as expected) Hunter did not use epoxy but rather polyester resin for the plywood; this rotted from the bottom upwards and the whole thing was like wet cardboard (but easily removable using bare hands!).
I made a 3-piece sole which has been in and out of the boat so often I wonder I can still find all the pieces. This is because everything else started to get redone all at once. I made new mahogany joists for under the sole which raised the sole height an inch or so; it reduced the headroom but enabled a bilge pump under the sole and let the whole sole be one flat rectangular plane (no slants but in the head, no angled sides except at the q-berth). It is in 3 sections because the outer sides are fixed against the bunk fronts (and all this first had to be sufficiently rebuilt and epoxied to within a hairbreadth of life itself, as it is all structural); and the center section is a series of three lift-out panels, one under the table and two aft, one for the bilge pump and one for the fresh-water valves.
If you need to replace it exactly as it was, use good 1/2" plywood, epoxy thoroughly, and bed with 5200. I used 'baseboards' on the bunk fronts to jam it down tightly against the hull. Then I took them off and am making nice new ones of varnished mahogany. DO NOT use pressure-treated plywood from the DIY-- please. It is no bargain, not structurally sound, and nothing will stick to it. You can make a pattern from the old piece(s) or from a piece of junk plywood or flakeboard. It does not have to be exact; get it close but too small and take 'soundings' laterally at certain points mapping the necessary additions before going to the good piece. You do not have to bevel the edges too much if you use 5200. Fill the seam against the hull with excess 5200 (use a squeegee) and 'glass over the seam with epoxy and mat. Do not forget to build in access holes for the keel bolts, etc. (before installation!). Model them on the ones under the bunk tops. I used white pine, thoroughly epoxy-saturated, for all the fiddles that hold them up. Those things are absolutely structural by now and way better than the (untreated white pine) ones Hunter installed in 1974.
I used 1/2" okoume plywood for my sole and hate it. If I had this to do over it would be in mahogany plywood. The okoume has a lousy core, it warps to sin, it checks and chips easily, and though it takes epoxy well it's still too flexible for my liking. (I also don't know how to spell it
.) Its only merit is that it looks pretty when varnished (and it's cheap). I am going to do the sole over in Interlux Interdeck. The strakes separating the three sections are varnished mahogany and stand proud about 1/4" just enough to catch your heels when sitting below at a heel angle.
I made a new compression post out of Western white spruce, two 2x4s of it epoxied together. It looks nice now that I put an elegant bead molding on the corners. I would NOT use any other wood (well maybe mahogany) and at ALL COSTS pressure-treated yellow pine is the LAST thing you want to use-- never never NEVER. (Don't get me started. :naughty
I do not know what you mean by 'I just don't put it under a lot of stress while sailing'. How is this stress calculated? How much stress is enough and how much is too much? With respect-- I would NEVER go sailing without an adequate spar-support structure. I wouldn't even rig the boat. A good compression post can be easily made or contracted and installed. I know we all like to go sailing, but you may not realize what else is happening to the boat. The whole hull is probably distorting the moment you heel even a few degrees. This works chainplates and keel bolts. My boat got moved in the yard when I had not finished rebedding the keel and when I got to it again I found all my aforementioned mahogany sole joists had popped off the inside of the hull. Fortunately the keel did not drop off (5200. Nuts on the keel bolts were loose. Still held on). Please fix the boat ASAP and don't 'put it under' any stress at all till you know the mast isn't going to plunge through the deck like a harpoon (missile).
