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Wooden Boat Building and Restoration

Floor

New stringers and floor frames were installed next to support a plywood floor covered with marine vinyl flooring. Nautloex was used for the marine vinyl floor covering.

The stingers and floor frames were all made of white oak.  The challenge with the floor stringers (there are four of them) was to establish a level crowned plane for the floor frames to be mounted on. This was challenging because the stringers set on the very bottom of the boat which not only isn’t level, its also slightly curved. A "rolling bevel" has to be shaped on the bottom edge of the stringers in order to fit properly. A “rolling bevel” is a bevel that continuously changes from one end of the piece to the other end. For example, the bevel could be angled at 10° at one end and at 30° at the other end.  

To cut and shape the the bottom edge of the stringers, a band saw could be used that has been slightly modified specifically to cut rolling bevels. The best way would be to use a shipsaw, but most of us don't have access to one, they are vintage. I don't think there's a company that manufactures shipsaws today. The band saw modifications involve installing an extended lever for adjusting the angle of the cutting table from the back (outfeed) of the saw, and installing a larger bevel gauge that can be easily read from the back of the saw. However it becomes a two person task to cut the rolling bevel. Before cutting, the various angle measurements along the length of the cut are marked and labeled along the cutting line on the stringer. Then one person guides the stringer through the band saw calling out the angles measurements as they approach the saw blade, while the other person adjusts the tilt of band saw table using the extended lever and referring to the bevel gauge. It can work remarkably well.

Since I’m working alone, the only other way (that I know of anyway) is to do this is by shaping the bevel by hand with hand plane after the overall curve has been rough cut on the band saw. It takes more time and patience but it certainly is a doable task.

These pictures show the stringers being shaped by hand. If you look closely you can see the curves of the stringers as well various angle of the bevel at different points down the length of the stringer.

             


Once shaped, the four stringers were secured to the hull frames with pocket holes and silicon bronze screws. The original stringers were fastened from the opposite side  through the hull's frames, before the boat was planked. But with the hull now fully planked, that is no longer feasible. So the next best option is pocket screwing while being very careful not to drive the screws completely through the hull... not as strong as fastened from below through the frames, but strong enough.

             


After the stringers were installed they were primed with Interlux Epoxy Primekote and painted with Interlux Bilgekote. The bottom edge was primed and painted before installation.


Next was laying down the floor frames. These too were of White Oak. This went quick and easy. The strings were shaped for a crown so the floor will shed water. Now that the floor frames are down the crown shape is visible.

             


Once cut to size and laid out the floor frames were removed, primed, painted and reinstalled, so to be able to paint all surfaces of the floor frames. Once cut to size and laid out the floor frames were removed, primed, painted and reinstalled, so to be able to paint all surfaces of the floor frames.


Next, plywood panels, made of marine grade Fir, were shaped to size. First the new gas tank was mounted so the plywood panels could be fit to them. The panels were brushed with Interlux Interprime Wood Sealer in preparation to be covered with vinyl.

             

 



Last the sealed plywood panels were coated with Nautolex 88 Adhesive, covered with Nautolex Vinyl, pulled tight and stapled underneath using stainless steel staples. They were fastened to the floor frames using stainless steel machine screws, stainless steel finish washers, and stainless steel threaded inserts.