Boom-enstein

With Yard and Mast completed, I turned my attention to the boom.  Part of the reason is because I happened upon what I thought was a nice 2x8 x10’ board at Home Depot.  As it turn out, I got almost all of the required lumber from that one board, but there were some knots in just the wrong places to make that a reality.  But I have some leftover off fall from the previous yard(s) and other home improvement projects and was able to make up for the shortage.  Once again, the approach is to laminate two halves together, each one with a couple of scarf joints to get to the required length (just barely).

This post’s title comes from the ugly mish-mash of lumber.  In order to eliminate knots with what was available, the joints on one half cut across the wide side and on the other across the narrow side.  Hard to put into words, but these pics might illustrate better.

Even so, I still had a few knots that I had to be very careful to position towards the outer faces so they would be removed with the final planing and tapering.

Sadly, the mating of the two halves did not go as smoothly as the scarf joints did.  I thought I slathered enough epoxy on, but it is a pretty long spar and I guess the ‘’pox got spread a little thin in places.  The wood does tend to soak epoxy up in unpredictable ways as well.  The result was starvation in few spots.

What the seam should look like:

What happened in multiple places:

After consulting my support/enabler group, I made the decision to simply squish more epoxy into the gaps rather than disassemble the spar (i.e. cutting it half up the seam and starting over).  These pics were taken after I planed the sides down to the plan’s taper specification.  I figured there’s no point in adding more glue only to plane it away later.  As I write this the gaps have been filed and are drying in the basement.

One lesson I learned is to be more generous with the dimensions of the blank, leaving plenty of material to plane down to get to the final shape.  As a result, I could make this boom much thicker in the vertical dimension that the plan calls for.  I may do that based on the forum’s feedback.  The consensus is that a stiffer boom is better, particularly if going loose footed.  I wasn’t planing a loose footed sail, but I might give myself that option by making the boom beefier.  Stay tuned to find out what I decided on. (I can’t wait to find out myself!)

Next up: oars