The past couple of days I have been working on fixing the pitch pocket in the bowsprit. I started out by removing most of the pitch and other detritus.
After this, I took a chisel and made a more rectangular cutout with ramped ends.
I then took a leftover piece of douglas fir and planed one edge smooth, cut it to length, then used a hatchet to split it to approximate thickness. After this, I used a chisel to shape the piece until it at least approximated the shape of the pocket to be filled.
Then I used a combination of chisel and rasp to shape the plug. I also checked fit by rubbing pencil graphite on the plug and looking for where it was deposited. After a few iterations of this, I had the plug as close as it was going to get.
As I knew there were still voids to be filled under the plug, I wanted a structural filler for the epoxy. I took a short piece of fiberglass tape and cut it into roughly 4x6mm pieces. This gave a range of pieces from about 3mm up to 6mm. I mixed a small batch of epoxy and coated the faying surfaces with neat epoxy, to prevent a starved joint.
I then mixed some of the chopped glass to the remaining epoxy to yield an interestingly stringy mixture.
I also added a bit of wood flour, both as a thickener, and to help match color. I then glopped a bit of this goo into the pocket in the wood.
Finally, I placed the plug into place and pressed it into place. I then wiped most of the squeeze-out away (much easier to do before it cures).
At this point, all that remained was to clamp things into place and let it cure.
Hopefully tomorrow or the next day I can remove the clamps and machine the plug until it is flush with the surrounding material. Then I can finish the bowsprit and heave a sigh of relief that another piece is basically finished.
Regarding the title: I have been informed that the technical term for a piece used in this type of repair is a “graving piece.”