As you know already, the original guideboat builders sealed the joinery between planks by driving and clinching a double row of tacks along the plank seams. One row was driven from the outside toward the inside and the second from the inside toward the outside. The rows were laid out so the the tacks were staggered, thus getting the most watertight seam possible.
A problem arose at the stem ends. Here the hull narrows so much that it is impossible to get enough throw with a tack hammer to drive tacks from between the number 12 rib and the stem. What to do? The old timers still drove a double row of tacks in that region but the tacks were all driven from the outside inwards.
I decided to do the same but I waited until the hull was off the builder’s jig and upright. I thought it would be far easier working with hull upright. Indeed I was right; I could more easily see what I was doing.
I puzzled over how to lay out the tacks. How does one quickly and easily draw a line on the outside of the hull where the tacks will line so as to be in a straight line? I hit on a simple solution; use a strip of masking tape placed along where the new row is to go. Once the masking tape is in place it is a simple manner to use a pencil to mark the half way point between the existing row of tacks where the new row will be put down.
Another problem arises in trying to clinch tacks way up near the stems in the bow and stern. There just isn’t enough room there to use a clinching iron. I solved that problem by taking the handle off an old slick and jamming it up between the stem and planking in this no man’s land. It was a bit awkward, but it worked.
The double row of offset copper tacks lent a very attractive accent to the hull. I was glad I took the extra time to add this classy touch. By the way, there are about 1000 tacks in these bow and stern quarters.