Floorboards

Starting to install floorboards.  Here you can see the first four floorboards are in place on the port side and on the starboard side of the Centerboard (CB) trunk.  As you can see a cutout has been made in the two center floorboards for the CB trunk.  

Putting in Floorboards

As discussed in a previous post, I have deviated from the plans.  The floorboards do not go all the way to Bulkhead 8 (BH8) as planned.  Instead they stop approximately 6" forward of BH8 to allow access to the drain plug I am planning to add later.  

New Floor Joist

So that the ends of the floorboards will not be free-floating, I have built a new floor joist for them to rest on.  The joist is also beveled approximately 4.5 degrees longitudinally on the bottom to better fit the hull at that point.  I have made the joist from a piece of 3/4" x 3" lumber so that it does not quite reach the bottom of the hull at the middle.  This creates a limber hole for any bilge water to flow through, and also means I do not have to try to fit the joist to the fillet on the bottom inside of the hull.  You cannot see a small cleat I added at the back of the joist to support a lift-out door I will install between the new joist and BH8.

Curve Spline (Batten)

Where the floorboards meet the curved portion of the hull, they are first cut slightly too large and a spline (boatbuilders call it a batten) is being held in place by lead weights.  The spline is used to draw the proper curve, then the floorboards are removed and cut, then sanded to meet the line.  There is also a 15-degree bevel on the outside of the curve.  You can't see the pencil lines, but sections will be cut out of the second and third boards on each side of the CB trunk to provide lift-out covers over compartments for another 200 pounds or so of lead ballast.

Update: You may have noticed the comment from fellow builder, Craig, asking me to explain my method of fitting the floorboards.  As he said others have resorted to the "trial-and-error" method, which would involve climbing in and out of the boat about 100 times more often than I could possibly stand.  Before cutting the boards I thought about this for quite a while and was worried that I would not be able to do it very well without ruining a few boards.  I finally decided to use cardboard templates, which worked very well--much better than I had hoped.  I used two sheets of heavy cardboard, 4-feet long, end to end (with a gap of about 5/8 inch).  The templates were cut about 1/2-inch "proud" and it was easy to check the templates against the floor joists and make new cuts if necessary.  The templates were butted against floorboard 4 on each side, i.e., the last full-length floorboard with almost no curve cut in it.  As each floorboard was added, I marked where it intersected with the templates on each end, remembering to add the 1/8-inch gaps.  After cutting the boards just outside the lines with a band-saw, I then sanded them down to the line. I used a belt sander for this, with the platform tilted down to 15 degrees to give the boards a little inward bevel where they meet the angled hull.  A greater bevel of about 30 degrees or more might have made for a snugger fit, but I was afraid it would make the edges too sharp and weak.  After mounting all the boards temporarily, I used the batten (spline) to create a fair curve near the hull, then re-cut the boards "proud" and sanded them down to the line.  The batten I used was only 1/8-inch thick, which made it much easier to curve and hold in place with lead weights than the thicker battens recommended in the manual.  This required me to always hold the batten in place near where I was using a pencil, but other than that I found it to work very well.  As a test of my accuracy, I laid the two shortest boards (the ones with the curve all the way along one side) together, top to top, for comparison.  I am happy to report that they were a near-exact match.

Floorboards in Place

And here you can see the nearly finished floorboards temporarily screwed to the joists (too bad the screw alignment is not perfectly straight--I noticed too late that some of them were getting too close to the edges of the cleats).  Next they will be removed and have their edges rounded over with a router.  There is a little rasping to do at some of the edges to make them fit the hull better, then the boards will be sanded and have Danish oil applied. That should give the cheap pine boards a warm, inviting hue.   After that, they will be permanently mounted back in the boat, but while they are out of the boat the inside of the hull will be painted.  In the picture I also see the large metal curve that was very useful in drawing the cut-lines.

Before I remove the floorboards though, I will probably build the lift-out door at the aft end of the floor, that as I said is to provide access to the drain plug.  That way I can finish the whole floor together.  At the centerboard and aft of it, there will never be much weight on the floor because it will be below the cockpit, i.e., you can't stand up on it.  The most I will ever do back there is lie on the floor to check the drain plug, and maybe store a few things, including a small "potty."  (Since writing the above I have decided to build the rear lift-out section later, after installing the rest of the cockpit floor.)