The second plank goes on, some 'glassing, and (yes) more spiling

With the second plank cut out and test-fitted, next up is the 'glassing of the bottom and garboards.  Actually, I used Dynel cloth, epoxy-saturated, so I suppose 'glassing is not the right term.  But the process is the same:  cutting the fabric roughly to size, mixing up the epoxy, wetting out the cloth with resin, trimming off the excess cloth with a razor knife after the resin has dried a bit.

Here's the dynel cloth glued to the bottom/garboards.  I'd say dynel is easier to work with than fiberglass cloth, and some say it is more resistant to tearing.  In any case, epoxy-saturated dynel over 5/8" ply--not to mention the outer keel, which comes later--will be plenty rugged for this boat.  Note the blue tape around the edges that you can see under the dynel.  This prevents the epoxy from gluing the rough edges to the boat and gives a clear line for knifing off the excess cloth.

Here's the dynel job with the rough edges cut off.  Note that the dynel does NOT extend all the way to the end of  the plank.  That's because the last 1" is beveled for gluing to the next plank;  no need to dynel that part.

Here's plank number two going on the boat. As mentioned earlier, this is the first of the 1/4" planks, so it bends quite a bit easier than the 3/8" garboards.

To cut the gain along the edge of the plank, a rabbet plane and a piece of scrap nailed 1" from the edge does the job.   

With the first plank glued on, time to do the other side.  If you look closely you can just make out the fact that the plank lap "disappears" into the stem;  the result of the gains cut in the plank.  Recall that once planking is done there will be an outer stem glued and bolted to the inner stem, what you see here is the inner stem.

Time to spile the third plank.  I found that I was just able to get the third plank out of my scarfed 1/4" plywood sheet, which is not quite 16' long since the scarf "robs" some length, with only about 1/8" to spare.  Lucky!  For the next three planks, however, I'll need longer sheets for the planking.   Since this boat has overhang both bow and stern, the planks get longer as you go along.  That'll mean a second scarf to get the total length over 16'.   I might have purchased a few 10' sheets of plywood, which are available from some dealers, but I think I'll use what I've got.  (Note:  The rectangular thing hanging from the mold is a longboard used for sanding hulls and such. I'll try to clean up better in my next batch of pictures!)

A piece of left-over 1/4" ply is glued to the end to get the length I need to do the final three planks.  I'll need about 16'3"-16'6" for the fourth and fifth planks and 17'0" for the last plank, also known as the sheerstrake.  By the way, I'm doing all my scarfing and plank layout and cutting on the floor.  Why?  Well, there are a lot of advantages to building your boat in a well-equiped boat shop...but I can hardly take away precious bench space from a paying job!  I'm building BELLE in my spare time at the shop, it's been a great arrangement for me which I really appreciate.   The floor is fine for these jobs.  (OK maybe next time I'll make a temporary planking bench from sawhorses...)

Well the second plank is on.  My one concern is my molds are quite far apart (28") and I'm worried the 1/4" ply won't have enough stiffness \ to naturally follow a fair curve between the molds.  There was no problem with the 3/8" garboard, but the 1/4" is significantly "floppier".  I  think I'll try a slightly different technique in gluing up the remaining 1/4" planks.  Stay tuned!

Floors and second plank (almost)

Since last time I've gotten the floors in and also installed the second plank...well almost.  I need to 'glass the bottom first, but I went ahead and spiled and cut out the second plank (one of the broadstrakes) just to take a look.

I'm kind of liking this building upside-down thing. Sanding dust and such falls right out of the boat and, except for working on the bottom itself, everything is at a convenient working height. Normally I might quickly plank the boat, flip it over, and finish it off right-side up. But I think I might try installing a few bulkheads and such while the boat is still upside-down.

To fit the floors, I first temporarily clamped them in the correct location across the boat. This makes it easy to mark them for length and the various bevels.  In addition to providing additional stiffness to the bottom, the floors help support the joint between the garboard and the bottom plus they provide convenient beams on which to place the floorboards.

Here's a completed floor, glued and screwed in place.  Note multiple limber holes.

Repeating the same spiling process as for the garboard, I got out the next plank. The plank is left long (the full length of the scarfed plywood) just in case it needs some jiggering fore-and-aft which, in this case, it did not. This is the first of the 1/4"-thick planks--recall that the garboard was 3/8"--and it bends easily into place.  The bottom edge does not have any reverse curve up forward the way the garboard has.   Since I'm happy with the fit on the boat, I go ahead and make a second plank for the other side. 

 I'm spiling the planks so that there is a 1" lap, a bit wider than the more typical 3/4" lap used with 1/4" planking.  I figure it'll add some ruggedness with just a little cost in weight and material.  This plank, which has just been cut, still needs gains cut in, fore and aft, like the garboard.  With the gains done, the lap will "fade" into the stem and transom.

The shortest plank on the boat is the garboard;  the longest is the sheer plank. Note that there's just a little bit of overhang of this plank here at the stern and at the bow.  The plywood that I used to cut out this plank is about 15'10" long:  the length of the two 8ft sheets of plywood minus the 2" scarf.   I'll be scarfing on more plywood to make some of the longer planks, for sure, but I hope the next one won't need it...we'll see.

À bientôt...

Garboards

With the bottom in place, I can move on to the garboards...the first of six pairs of planks to go on the boat:

First I beveled the edge of the bottom to accept the planking.  This is a rolling bevel--that is, the angle of the bevel changes as you go from the stern to the bow of the boat--so reasonable care should be taken that the bevel is correct.  I tried putting a batten along the upper edge of the plank--already marked on the molds, remember?-- then used a piece of straight-edged scrap to check the bevel.  I started with a power planer and finished with a hand plane.  Note the notch in the scrap (right under my palm in the photo).  It is the same depth as the thickness as the batten.  Without the notch, the bevel would be off a few degrees. 

Next up, I used a rabbet plane to cut a gain (about 16" long) in the aft end of the bottom.  Each plank with have a gain like this one, except this one is quite a bit wider.  In BELLE,  the angle between the bottom and the garboard is very small at the transom.  Thus the joint is really more of a scarf than a lap.   I thus specified a 3" gain (i.e., 8x3/8" like an 8:1 scarf) rather than the more common 3/4" to 1" that I'll use for the other planks.

OK now I have nifty bevel and gain.  How do I determine the shape of the garboard so I can cut it out of my expensive sheets of plywood?  Many boat plans these days come with patterns  for all the planks, but BELLE is the prototype of a new design, so such timesavers don't exist.  Instead, I'll use the tried-and-true technique of spiling.  Too many details to cover here, but basically the idea is you make a spiling batten slightly narrower than the final plank and mark it with something (in this case a compass) to take the shape of the plank right off the boat.  Confused?  Spiling is covered in some detail in quite a few boat building books, including this one, or try this description.  Or see my list of recommended boat building books in the FAQ.  Sorry, gotta move on!

Here's the spiling batten--hot-glued from a few scrap pieces of luan plywood--in place, seen from the bow.  It is lightly nailed to a few of the molds and clamped to the stem, without any edge set. That is, it's important to let the batten fall "naturally" on the boat, without forcing or twisting.

Here's a beauty shot of the spiling batten on top of the plank I cut from it on top of the remaining 3/8" plywood for the other garboard.  Of course, I'll need two garboards, one for each side (I hear a one-sided boat gets a bit wet at times).  If you look carefully, you'll see a pretty pronounced reverse curve in the forward part of the plank, which is nearest the camera in this photo.  Garboards often have unusual shapes like this.  Just part of the game.

After test fitting the plank (not shown), it's time to glue.  Note packing tape on transom and edges of the molds.  Don't want to glue the planking to the molds, or huge gobs of glue on the varnished transom.

Here's the first garboard going on.  Blocks of scrap ply covered in packing tape, screwed with sheet-rock screws, make good "clamps" in places where clamping is difficult.  A tip:  use new sheetrock screws because old ones are often "torqued" and seem to break easier than fresh ones. 

The other garboard going on. Only ten more planks to go, five per side!

I'd love to just keep planking, but maybe there's a better next step for this boat. There's a bunch of floors to put in...I'm talking about nautical "floors", not the"sole"...which I'd like to back-fasten through the bottom.  So how about this:   install all the floors with their nice back-fastened screws, then 'glass the bottom/garboards, then back to planking.  Normally I'd install the floors after planking was completed and the boat flipped over, but then I'd have to flip the boat back over to do the 'glassing.  Better to do it now, I think...

Until next time.

New Page

Today's post will be a quick one, just to alert you that there's a new Page on the blog:

Sketches and Plans

Plus I updated the FAQ with a couple of new questions.  These Pages are linked in a box over on the right-hand side.  For now, anyway, I think that will do it for Pages...back to boatbuilding!  I'll have an update on building progress soon...