First Timer - Need Help Fixing Rookie Mistake

[AndrewT]

Argh.

Finished the lapstrake sides of the hull Friday night, then took most of yesterday off to go pick up a 1957 Johnson 35hp motor to hang on the transom (if I ever get to that point). When I got back to work last night, my intent was to start installing the cross-planked bottom.

However, it quickly became apparent that the inner keel, which is already glued & screwed to the stem and notched into the transom, is too high in the after third of the hull. A plank laid across the hull from chine to chine actually sits up on the inner keel, which appears to be 1/4" or so proud for about the last 36" of the bottom.

I've hit it with a belt sander and a power planer and the going is very slow indeed, and I'm afraid it's going to end up like that old story about cutting the legs on a wobbly table. You cut this one, then that one, then the other one, then this one again, etc. and the table ends up 6" from the floor. I'd love to figure out a way to register a router to the height of the chines and just use that to shave the inner keel to the exact same height, but either I'm not that smart or I haven't had enough caffeine yet this morning.

Any suggestions?

[ChrisBen]

Argh.the inner keel, which is already glued & screwed to the stem and notched into the transom, is too high in the after third of the hull.

If the inner keel is flat and not somehow bowed up, then the problem is not with the inner keel but rather, the last 36" or so of your bottom planks are to low.

[Bob Smalser]

No biggie.

If you release the keelson from the transom so it can slide in the mortise you cut for it there, you should be able to get all the planks flat when installed from bow to stern in sequence. You can re-attach the keelson to the transom prior to installing the last plank.

But if I absolutely had to, I wouldn't hesitate to either glue a quarter-inch cheater to the lowest plank, or even mill a slight dado to fit the keelson in the high planks.

[Peerie Maa]

Bob gives you the best method.
But if you cannot free the keelson and can afford to lose the thickness, try this.
Find a straight batten longer than the width of your bottom. Cut a notch in its middle that clears the width and depth of the keelson. You can then use it to scribe a line on the keelson sides defining the amount of wood to cut off. Saw kerfs joining each scribed line on the sides, and use a chisel or slick to remove the waste, followed by a plane or shave to fair the new surface.

[AndrewT]

The planks are not installed yet; I actually did consider milling a mortise (or notch, more accurately) into the last few planks just before the transom but I wasn't sure if that was kosher. Plans say to start at the transom and work forward...as of right now, no planks are installed. A level placed across the hull indicates the forward section of the inner keel is okay (or at least more okay than the after section).

[ChrisBen]

If you try to plane/sand that extra height off the inner keel your bottom will no longer be flat. It may be flat side to side but your just transferring the error, you'll have a slight hollow on the aft end of the bottom as viewed from the side. Better to fix the planks.

[SamSam]

Just a guess, but since you say there's a 'funky hump' in the sheer http://forum.woodenboat.com/showthre...sheer-be-fixed , maybe the problem isn't the keel but the side planks, as ChrisBen suggests.

[Tom Lathrop]

Wait a minute here. Since you have 35 horses going on this skiff, it is a planing boat, right? In that case, you want the aft bottom flat, fore and aft and you need to know where the problem is. Put a straightedge over the aft keelson and see if it is flat. If it is, then you need to fix the problem on the side planking, as Bob suggests. If the keelson is not flat, then fix the problem there. The main issue here is not structural but effect of the cure on performance. If both keelson and side planks have level aspect, then the transom is probably wrong, holding the keelson too high.

Of course, there may be a design problem.