Losing the computer program which detailed how high each of the frames should have been mounted, was a serious discouragement. I no longer had a visual reference for the transom, and the slope the keel toward the bow, etc. There was a few days when I seriously debated whether to quit or try to restart another way.
All through that time, the physical frames back from the CNC shop were stacked against the shop wall. It was hard to get motivated to use them, but they were way too big and too expensive to put in the trash.
I did know they were all in the same scale, symmetrical, and I knew their longitudinal positions in feet from the stern: 2.0, 4.5, 7.0, 10.0, 12.5, 15.0, 17.0 and 19.0 feet. In addition, the five near the stern all had the pre-cut interior floor line.
So, I pulled up another similar boat elevation (above) and made some vertical measurements of the top profile. On a table, I lined up Frames 5,6,7,8 and arranged them in a gradually increasing drop down using the height information.
Building a large side to side symmetric object like a boat, benefits from as much precision planning as possible. But sooner or later, when the time comes to create a fair line, precise measuring gives way to the feeling of running your hand over the curve, or inspecting it with your eye. It was far earlier than I planned, but now was the only option to proceed. In a way, it gave me a kindred spirit to the boat builders of previous centuries, who started and finished with little tech help.
The photo below tells a good story of the last few months. Those two desks are for the Butlers, just before going to the finish shop. They are beautiful white oak, with respect for the Craftsman Style, and show some satisfying proportions. Look at the 1 : 1.6 relationships of the drawer heights, the solid leg size, and the strong horizontal top line repeated at the shoulder and at the bottom of the drawers. I already miss having them in the shop!
But success at anything often requires saying no to lots of things. And there sat the cross frames, asking not for a little time in the sun, but for an immediate and long term commitment. It was time to begin winging it.
This go around, I did put down some cheap plywood and framed it with carpet remnants to absorb the dirt and epoxy that would eventually create a genuine mess. Then I cut some four foot 2 x 4s and spring clamped the first frame at a comfortable working height. The wood clamp on the floor is to keep the assembly standing up temporarily.
Frames 1-4 are now roughly hung in space, and life is getting crowded as the desks are still holding their own.
Now the process of precision alignment, and building a strong back, began. I used the straightest 2 x 6 pine lumber I could find, put some paint cans under it, and screwed it to the first frame leg, as perpendicular as possible. Then I made the short blocks with an eccentric adjustment hole, so I could turn it a bit up or down, to set the floor line to a consistent height and level side to side.
As I worked forward, mounting each frame, I used several reference points, like the height from the shop floor to the frame boat floor line. Then I used a long straight edges to see if the chine ledge was level as intended through the first three frames. The long curved stick was used to help visualize whether the chine point was developing a lump or fair curve. A large constructed object soon loses perfect accuracy to all of the 3D reference points, but the better related they are in the beginning, the easier at the end.
Finally, I added a post to the front of the frame, with a center string to line up all of the ones behind. Below the seventh frame is going through the same process, setting height and level with the eccentric blocks, and centering to the string.
Another helpful visual tool below was to put small nails at the angle of the chine step, and run a string the length of the frames. By moving your eye along, it is not so difficult to see alignment issues. Frame mounting was all of that, setting height, level, centered, correct spacing, and review of the places it should be straight, and where curved fairly. Then it was time to call it good enough.
Life builds in many tests of commitment. With a little persistence, creativity, hard work, and a lot more persistence, you can get back on track . . .
One thought on “Cross Frames and the Strong Back”
I thought that might happen Dad. If you can design it one time, you can do it again. Good persistence.