Building Frame


Mould stations are cut out using the full-sized plans. Here Station #3 is ready for its spall (crosspiece). We used 3/4" strawboard -- it worked just fine, and was cheap too.

The basic 2"x 6" ladder frame is in place. As the lumber I was able to buy was not quite straight enough to use the lower edge as a baseline, I just ran a string centered below the crosspieces and leveled the frame using this reference. Once longitudinally level, I leveled the frame laterally by adjusting the lengths of the short legs seen here. Once triple-checked, everything was screwed in place.

The midships (Stn. #5) mould goes on first. The 2"x 4" vertical supports are installed and the controlling face of the mould (on the other side) is exactly on the station line and perpendicular to the baseline. The clamps allowed for the many tiny adjustments needed to get the waterline (not the spall), perfectly level and exactly 48 inches above the string baseline. Once level I used a plumb bob to center the moulds on the centreline.

All nine moulds up in a surprisingly short time. Though more complicated to set up than a small boat's building frame, it was quite easy to do in only several hours time. Note the horizontal support from #8 to #9. The end moulds needed more support so I did the same for #1 and #2 as well.

After visually checking general alignment from various different angles, a batten is tried over the moulds looking for high or low spots and getting a feel for the boat's lines and shape. The horizontal supports from #1 to #2 and from #2 to #3 are visible here.

Finally, a narrow batten (1/2"x3/4" Douglas Fir) is tacked over the plank lands (overlaps) and the plank lines carefully sighted for any unfair curves or other problems with the moulds. Particular attention was paid to the sheer line. No alignment problems were found and the lines were fair and sweet the very first time. Here the hog (keelson) has been cut to its width and is being tried in its notches, trimming the moulds a little so it will lie correctly. It is made up of two laminations of 3/4" stock. The final step in the preparation of the building frame will be to tape all surfaces contacting the planking, stem, or stern, with clear packing tape, so we don't glue the hull to the frame. I like to use the clear stuff as it will be necessary to find the plank lands (which were marked on each mould) later.


© Dale Hymanyk 2022