Showing posts from December 1, 2013

Second Plank

The second pair of planks went on today, the first pair for which the wedge-clamps are used.  I waxed the jaws of the clamps with paraffin to reduce the chance of gluing clamps to the boat.

I marked the fit for both planks, traced the lands from beneath, taped off the plank to reduce squeeze-out mess, and cut the attachment gains to match the receiving gains on the garboard.

I confess confusion about how these matching gains should best be cut.  Both books I have are vague about it.  I cut 9 inch gains on the garboard strake, cutting down through two of the three plies (the face veneer is thinner than the midline veneer... about 25% of the total thickness for each face, 50% for the inside one.).  The slope of the ramp is linear for the length of the gain.

The corresponding (attachement) gain for the next plank is cut on the inboard side of the plank where it mates with the existing plank.  But how long and how deep to cut it?  I'm just guessing.

The objective is for the overlappi…

Rinse, repeat

I stripped off the clamps on the garboard horns, cleaned up the squeeze-out, cut the gains, and beveled the plank landings in preparation for hanging the second plank.  The results are encouraging.

There are no signs of unfairness in the garboard strake, and the stem landing looks solid and shapely.   Plenty of squeeze-out in appropriate places all along the keelson.  I trimmed the plank overhang at the transom and cut the gains (the gradual, sloping reveal in the plank where the next plank lands, and gradually transitions from a lapped plank to flush joints where the planks meet the stem).  I'm cutting 9 inch gains (pictured above).

Next, I tacked battens to the beveled landing edge of the garboard and one to the next landing marks on the frame stations, and hot-glued strips in triangular patterns to create the next pattern for the next pair of strakes.  I traced the pattern on paired sheets of the okume plywood and cut them out with the dozuki razor saw.

I positioned the  plank…

Plank On!

The garboard strake is in place.  I spent an hour or so fussing with the fit, did a dry run layup, recut the bow section to a closer fit, and repaired to my Mom's place to ponder how best to clamp it while the glue sets up (and build up my courage).  I settled on bronze annular ring nails for the keelson and the transom lands (rather than removable self-tapping screws or drywall screws).

I traced the position of the keelson and stem on the underside of the planks, took them off and taped off the gluing area so as to reduce the mess from squeezeout.

As cold as it is, I switched to the 'fast' hardener, installed a new set of pumps to measure proportionate aliquots, and ran through the sequence again.  Screwing up at this point would reduce my project to a messy pile of epoxy-contaminated wood.  It would be irresponsible even to burn it.

The protocol for glue-up is to coat the mating surfaces with straight epoxy, then mix up up some epoxy putty (some saw dust and microfiber …

Spiling for cheaters: the garboad plank is cut

Spiling is the process of transferring measurements from the boat frame to planking materials so that they can be cut and fitted.  It involves transferring measurements from the boat frame to a pattern, and subsequently to planking material via the geometry of intersecting arcs, and connecting control points with a long batten.  Fussy.  Instructions for spiling in the books I have are obscure and difficult to follow, and conventional wisdom suggests it is more easily learned from an experienced person.  After reading and re-reading, I found another approach that seems simpler, and I have adopted it, at least until it fails me.  It feels a bit like cheating, but it makes complete sense to me from the get-go.

The image above illustrates the alternative method.  Two battens are fixed to the frame along the planking marks, and adjusted so they appear fair.  Narrow strips (I used planking material scraps) are hot glued to the battens (in triangular patterns to assure rigidity).  Carefully…

The winding road

What was to have been a couple of days of sharpening dull edges has stretched into nearly a week. The viscosity of the holidays and the collection of some missing components for a sharpening station (and the fabrication of a simple jig for holding stones and setting honing guides) kept me busy.  So, too, the re-learning curve for the Lie-Nielson method of sharpening chisels and plane irons.

I've come to the conclusion that a diamond lapping plate to keep the stones flat is a necessity for maintaining the discipline of sharpening.  A regular diet of the coarsest grit wet & dry paper on a glass plate will do the trick in a pinch (I haven't found coaser than 150 yet).   Flattening the 800 grit stone took a couple of those the first time through, and another to re-flatten after the first spate of sharpening. And a lot of time.

The only good thing about not having sharpened recently is that I've done only modest amounts of damage to my better plane irons.  A concave stone …