Sunday, January 12, 2014

More Keel Work

Well, the holidays have come and gone. The past busy month and a half have left me with less time for boaty things. For the most time I've dealt with that by neglecting the internet portions of my boating hobby, though the building part has slowed a bit, too.

I'd been going back and forth about how to finish the keel. For better or worse, I'm going to go with the center layer of the keel running vertically. With that in mind, I've fit most of the wood needed, and I've started working out a method to drill for the keel bolts. I've discussed the issues involved at length in previous posts, so I'll mostly just show some pictures of how things are going.

I've left a recess for the lead ballast. The first layer will need to be cut away, too, but I'll leave it in as long as I can to add some strength to what would otherwise be a weak section in the middle. I've been doing my epoxy work in the basement for the last month or two, which involves moving the keel quite a bit. Here's another view.

I still have some things to work out at the stern. Namely how the outer stern post will fit against the deadwood. The pencil line in this view is a rough approximation of the final shape. If you look closely, you can see where I've drawn a grid on the deadwood. The squares are 3" on each side, which corresponds to 1/4" on the plans. I drew the corresponding grid on the plans, and marked on the deadwood where the curve should intersect the grid lines - well roughly, anyway. It needs to be tweaked a little bit, but it gives a good impression what the finished product will look like.

Here's a view from a different angle.

It's starting to come together. The next jobs are to figure out the keel/stern post interface, and glue the first two layers together. After that, I think the third layer should go very quickly, with relatively few pieces whose shapes can be found by tracing the already glued-up layers.

Monday, November 18, 2013

Working on the Keel. Decisions, Decisions.

With the stem epoxied in place, I began to work on the keel. I wasn't quite sure how to go about this, and as I was feeling my way through, I didn't take pictures for the most part. I began by crawling under the hull and marking the locations of the floors. (In a house, these would be called "joists", and the floor would be laid on the joists. In a boat, the "sole" is laid on the "floors." Just one of those nautical things.) Their locations are found relative to the "stations" which are the locations of the molds which give the hull it's shape as the planks are hung.

This may seem like a bit of procrastination, but in fact it was not. The keel bolts go through the keel and keelson, and are bolted through the floors. After marking their locations, I drilled a pilot hole vertically through the keelson with a long 1/8" bit. The keel bolts will be 1/2" and 3/8", but I wanted to drill through to find their location on the outside of the hull. That also showed me the location of each station. They are each separated by 29" horizontally, but the curvature of the hull makes it difficult to measure with any reliability on the outside of the hull.

Next, at each station, I cut the end of a 2x4 so that it would stand vertically when set on the hull. I measured the depth of the keel from the planking at each station, and cut the 2x4's to these lengths. Setting them on the hull shows where the bottom of the keel ought to be. The keel runs in a straight from the 3rd station to the 8th, I was a little bit surprised that they seemed to line up exactly as they ought to.

As I said, I didn't take many photos as I was working along, but this shot from later in the process shows the 2x4's at the 7th and 8th station.

I had a nice straight clear piece of sassafras, about 5 inches wide, that I was able to clamp to the 2x4's. With the edge of the board aligned with the tops of the 2x4's, this put the board in just the right position. For most of the length of the keel, it doesn't protrude much more than this from the bottom of the planking. I was able to fill the gap between the hull and the bottom of this board with a two offcuts from the stem, scribed to fit into place. You can see them in this picture, taken after they were epoxied in place.

At this point, I was a little unsure how best to proceed. The keel is to be three layers of (roughly) 3/4" stock. Is it best to fit one layer, and then add to that, or work "from the front to the back." I'm still not entirely sure, maybe I'll have it figured out by the time I finish with it. In any case, I kind of did both. I was able to scribe three more boards to fill in the deadwood near the stern.

At the same time, I began work on the second layer. Probably. I say that because I have some doubts about how I will do that. Some builders of this design have let the grain in the center layer run vertically, perpendicular to the grain of the outer layers. There are a couple advantages to this, but normally this kind of cross-grain construction is not desirable. Wood expands and contracts as it's moisture content varies. As it gains moisture, it doesn't expand uniformly, though. It expands more across the grain than along the grain. Plywood is made of thin sheets of wood, glued with the grain alternating in direction. This makes plywood "dimensionally stable." It's dimensions don't change much with changes in humidity. Construction the keel in this way would make it very stable, and also less likely to warp. Certain aspects of the construction are also simplified with this approach.

On the other hand, what will happen when the keel absorbs water, as it inevitably will, or dries out over the winter? The builders who have used this method have not had any complaints, but... Well, I don't know.

To the right, you can see the start of work on the center, vertical, layer. It's quite easy to cut these pieces to the correct shape. There are a lot of them, though, so it doesn't seem to be a time saver, though that was not the purpose. In any case, I'm a little undecided about whether to continue in this way or not. I think now that it may be just as easy to do three layers, all running fore and aft. I'll try to make some progress in other areas while I mull this over...

Here's another view of the situation.

Wednesday, November 6, 2013

Project Paralysis

Although this is my second boat building project, I still have difficulty overcoming doubt and uncertainty. How careful do my measurements need to be? How closely do I need to follow the lines? Am I doing this right? Am I building in mistakes today that will only be discovered when I launch her?

On the one hand, I'm pretty sure that I'm doing a reasonable job. On the other, though, I always worry that I'm about to make The Big Mistake That Ruins Everything. I feel this especially acutely when I'm making major and more or less irreversible changes. Hanging planks has always required overcoming some emotional hurdles, but after doing it twelve times, I wasn't slowed down too much by the thirteenth and fourteenth.

Now I'm faced with permanently affixing the outer stem to the hull with epoxy. As I contemplate this, I realize... that I have tools spread all over my shop. I really need to straighten up. And wood shavings that I haven't swept up. The most important thing right now is for me to check over the plans and make sure I know what size all the deck beams are supposed to be.

Honestly, I wouldn't get anywhere if I didn't trick myself into it. Here's how it goes:

After I hung the last plank, I knew the stem was the next step, and so I bought enough lumber and set it all out. I had the template for the stem, and I set the lumber out to try to find an optimal way to lay everything out. "I'm just laying boards on the workbench. I'm not really doing anything. I can stack them all up again when I'm done."

When I get things about as good as I think I can, "I'll just mark these positions. I can think about it later, but if I decide to go with this, then I'll be all set.

The next night I come back, and pick up where I left off. Since I've got the lumber all marked for cutting, I might as well go ahead and see how they really fit together. Once they are cut, I might as well glue them up. Then at that point, whatever my misgivings about how things have worked out so far, there's no reason not to keep working - cutting out the profile and shaping the leading edge. Even if there are problems with it, I might as well use it as practice, right? Then, at last, when I have everything done: "What? Am I going to start all over with the stem? Get more lumber? Waste all that work? No, time to epoxy this to the boat and move on."

"Just let me organize all my screwdrivers first."

Wednesday, October 23, 2013

The Stem, Part II

Having shaped the profile of the stem on the bandsaw, the sides now have to be shaped. The stem tapers from 2 1/4 inches at the hull to 1 1/2 inches at the leading edge. At the sheer, though, the stem must be left square, to receive a fitting for the bowsprit. This requires a transition, like the one shown on the cover of Chapelle's Boatbuilding. I've thought about how to do this for a long time, and I've really been looking forward to it.

First I marked out the width at the front of the stem, and measured back from the front face to about 1/8" from the back. The curve on the front was much more uniform than the back, which was shaped to fit the inner stem - as best I could. The concave face is much harder to shape, especially when it needs to match another surface. In the end, I got all the gaps to within a millimeter or so.

Next I marked the profile for the transition on the front face. It is a section of a circle with a radius of approximately 2 1/2 inches. I used a template for the arc, which I traced onto each side. (By "template" I mean the bottom of a can of Raid hornet spray.) After that, it was high school geometry. Using a compass and straight edge, I divided the distance from the edge to the bottom of the arc on the front face into halves and then quarters. I noted where these intersected the arc. Then I used my Veritas saddle square to project their locations onto the side of the stem. Next, I divided the distance between the front and back faces in halves and quarters. I marked the intersections of these lines with the projections from the front face.

In principle, these marks should lie on an arc of an ellipse. They did not, so I marked a nice looking curve the passed near those points. After all, it's a boat, not a homework assignment.

Then I sawed down close to the marks to define the area to be chiseled out. I've already started a little bit in this photo. Then, worked my way down to the lines. I worked down most of the stem with my power plane, but it couldn't get in close to this little detail. So I used a hammer and chisel to remove the bulk of the waste. Then I used the chisel by hand to clean things up. Finishing up with a rasp, the smallest plane I have, and then sandpaper. I think it turned out pretty well.

Friday, October 11, 2013

The Stem

With the hull finished, at least for now, I turn my attention to the backbone structure: The outer stem post, the keel, and the outer stern post. The best way to proceed seems to be to begin at the front and work my way backward. I use some long skinny scraps, which I've been holding onto for a long time to mark the profile of the stem. The arrow heads are tacked to a strip of 1-by material with hot glue.

Then I transfer the marks to a sheet of plywood. The astute observer will notice that the plywood is more scrap leftover from the building moulds.

After tracing the tips of the arrows, and springing a batten through the marks, The stem template is cut out and tried in place. A little light shows through. After numerous rounds of sanding down high spots, the fit has improved - a bit, anyway. Still there are spots where light shows through, but nowhere is it more than a millimeter off. Good enough for now. I'll still have to shape the stem itself.

I'd been feeling a bit jealous of builders like Richard in Canberra, Alec in Bermagui, and Ron in Sydney who have exotic tropical hardwoods, like jarrah, growing in their neighborhood. I'd not heard of this wood before, but I sounds like the perfect wood for keel construction, especially in epoxy based construction, where white oak would be questionable. It occurred to me, though, that jarrah isn't exotic to these builders, and they might view certain North American hardwoods as exotic. Like sassafras.

When I first started building, one of the early decisions I had to make was what wood to use for the keelson and inner stem and stern post. More generally, I was in a quandary about what to use for the interior framing - deck beams, carlins, frames, and such. Ash is traditional, but not rot resistant. Iroko? A bit pricy. I even called Iain Oughtred himself, who was very friendly and answered all my questions. On the subject of what wood to use, though, he basically said, "whatever you can get." Then I was reading my copy of Steward, who has this to say about sassafras:

Weight about 2.4 pounds [per board foot] (light). Moderately hard, moderately weak in bending. Highly resistant to decay... Freshly cut boards are said to have a sassafras odor, if you know what that is like!

I do know what it's like. I've seen it described as "spicy" or "like root beer," but that doesn't quite get it. It's wonderful. And it fills the shop every time you cut or sand the wood. WoodenBoat, meanwhile, has this to say:

Highly durable; has properties like ash but not so tough; once popular in light skiff construction.

Well, that did it for me. It's not a major commercial wood by any stretch of the imagination, but if you ask at lumberyards and look around, you can find it here and there. A phone call and a drive to a sawmill about an hour away, and I had the sassafras lumber for the inner stem and stern and the keelson. Now, after years of planking with meranti plywood, it's back to sassafras. At the left, you can see the stock that will become the outer stem.

Here's the general setup.

I'll use the plywood template to trace the curve of the stem onto the assembly after it is all glued together.

And this is the big glue-up.

One thing about sassafras is that the trees do not grow especially large and it's difficult to find nice clear boards. There were a couple knots that I couldn't work around - well, didn't work around. Before gluing everything together, I cut them out with a hole saw, and used the same saw to cut a plug from a clear section of another board.

When I noticed the knot on the back of the board (it didn't go all the way through, so I didn't notice when I laid out the cuts) I ought to have started over. I guess I was in "git 'er done" mode that night. I also could have tried to match the grain in the plug. Too late now. It's enshrined forever as a reminder to be more careful in the future. It may be below the waterline. If it's too glaringly obvious, I can always paint it, but probably not.

Gluing the nine boards together was a slippery. sticky mess. I typically work pretty pretty cleanly and carefully, but the bottom layer slid a little bit, leaving some gaps. I made the inner stem and stern this same way and, honestly, I can't remember a single thing about it. I remember gluing a copy of the full-size pattern on to cut out at the band saw, but nothing about the guue-up. I didn't have any trouble with misalignment of the boards, though. At least I don't think I did, they've been covered by the planking for a long time now. Did I drill holes through near the edges to stick a nail through while everything was clamped up? That would have been a really good idea. This is why you shouldn't take nine years off in the middle of your project. In case you wondered why more people don't to that. I filled these gaps with unthickened epoxy, which seeped right down in.

The next task is to trace the template onto the assembly...

...and then take it to the band saw. Not an easy cut to make all by myself, but by hook or by crook, I got the job done. More on that later.

Sunday, September 29, 2013

Tall Ships Erie

Tall Ships Erie 2013 took place on September 5-9. Celebrating Commodore Perry's victory in the Battle of Lake Erie on September 10, 1813 during the War of 1812, eight tall ships joined U.S. Brig Niagara at the port of Erie. Tens of thousands of visitors came to view the ships and get a taste of what life at sea is like. Here are some of the hilights:

St. Lawrence II- Kingston, ON:

Lynx, Portsmouth NH:

All in all, it was a good event. There were many, many people there. All the parking areas seemed to be full to capacity. (We ended up parking on the street.) The lines to get on each of the ships were long. I think the experience would have been enhanced by have a few crew members on the ships with a two minute talk about... something. Explaining how the ship operates ("These are the halyards, they raise and lower the sails...") or the maintenance that needs to be done. On one ship, one of the crew was repairing a block. She could have told everyone who walked past her what she was doing and why.

Then again, I guess they don't have to do that to draw in the crowds.

Thursday, September 5, 2013

Fiberglass: Not a Total Disaster

Labor Day Weekend was my big chance to fiberglass the hull, with plenty of time to lay the cloth and "fill the weave" with a couple more coats of epoxy in quick succession, avoiding the need to sand and ensuring a strong chemical bond between the coats. "The best-laid schemes o' mice an' men," as they say, "Gang aft agley." And oh, agley did they gang! No lasting damage was done... But I'm getting ahead of myself.

Here we see the bare hull. All the nicks and scratches have been filled and sanded smooth. All the edges and corners have been rounded. Not everything is completely "fair", but everything is smooth, so the fiberglass cloth can easily lay against it.

Here the first two panels of cloth are laid out. My original intent was to use a single length of cloth to cover each side, leaving only a small lens shape along the keel to cover with an additional sheet. Reading John Welsford's article, Fiberglassing Plywood, changed my mind. Five panels as shown will cover everything except small portions at the bow and stern.

Well, that's how it was supposed to go. I've discussed earlier the careful planning I did, the test piece I made up, how I made sure the cloth could adhere to the curves I'd prepared.

Did. Not. Work. At. All.

Apparently what works on a 3 square foot trial can not be assumed to work on the entirety of a 20' long, 6'8" beam boat. Or the planets were not aligned, or the gods not appeased, or something. I started at the top to work my way down from there. I moved to the bottom to work my way up. I tried in the middle. Pressing the cloth down on one side of the curve caused it to pop up on the other. Smoothing the cloth on the other side made it bulge on the one. Strong words didn't help. Not even the stomping of feet had any effect. Unbelievable.

In the end, I had to concede defeat. Before the epoxy kicked off, I pulled the glass cloth from the boat, and cooled my heels with an ice cold beverage - extra bitter. Only the one panel of epoxy cloth was ruined, a nice benefit of not doing the whole side at once, one I had not considered. The others can be used when I glass the decks or cabin top.

The weekend wasn't a total loss. I put two coats of epoxy on the whole hull, and it looks very nice. It's the first big change I've seen in a long time, so that's pretty satisfying. I'll need to sand out some unevenness, and maybe give one more coat of epoxy before it's ready to paint. First, though, I need to finish the keel and the stem and stern posts. Here is where things stand today:

As for the epoxy soaked fiberglass