Thursday, August 21, 2008

CRACK!

Boat building is a contact sport. So, with the forward port bottom planking in place, I started working on the starboard side, and figured it to be quick work. After touching up the edge along the keel, as well as the transition point, I began dry fitting it. Placing a few screws here and there, I secured the planking to the boat, moving aft to fore. Things were great until I got just past the stem transition point. Having failed to properly fair the stem just forward of the transition point, the wood had no place to bend. As I bent it, it bent back. Well, not really bent so much as cracked. Here's a picture of it, after it's in place, though the crack is still apparent:







After it cracked, I freaked out, took a timeout, and then went back to figure out where the problem was. After identifying the problem, I went back and did some more fairing. Although the picture doesn't look like it, the planking now sits essentially flat at that point. I filled it with epoxy as much as possible, and it will be strong enough to withstand any problems, especially after it gets the fiberglass treatment. There will be plenty of fairing to be done on the boat before fiberglassing, and this will be an obvious point needing attention.

Notwithstanding that faux pas, Jen and I were able to secure the starboard piece yesterday. There are a few gaps that will have to be filled, especially along the keel and a bit at the stem. Here's a picture of it at this point - it's nearly a boat!



Following are a couple other points of interest -

Here's a picture of the transition point on the chine - the aft material will be planed down this weekend:



Here's a picture of the transition point on the stem - this will also be planed down:



So that's where things are at this point. The next step is to prepare the boat for fiberglassing. Then I'll fiberglass it and paint it, and then (finally) it can be flipped over.

Bottom Planking

I just went searching for some pictures to summarize the bottom planking process, and realize that I basically don't have any at all. Mom and dad came down at the end of July to help out with things, and mom took a few pictures of things. To those interested in building the boat, and the process itself, I'm really sorry that I didn't take more pictures. I just don't tend to think about that until it's too late.

Here's one picture that's not really illustrative of the bottom planking process:



The bottom planking process is only as successful as the fairing of the keel, chine, battens and frames. As described in the instructions and plywood boat building book, you can most easily accomplish the fairing by using strips of plywood ran from the keel to the chine, using this as a guide to determine where material needs to be removed. This is a somewhat slow process, but it becomes easier over time, because you can fair at the frames and then adjust things as necessary between the frames. I can't stress this enough - spend a good amount of time and get the fairing right before you ever touch the plywood planking. The work became somewhat meditative, especially as I got better and better with planes.

After I did as much fairing as was reasonably possible, I got out the plywood. Because I am using 8' plywood sheets to plank a 14' boat, I would need four pieces of planking: two each fore and aft, on either side of the keel. The two aft pieces each required one sheet of 4' x 8' plywood; the two fore pieces were taken from one sheet of the same.

When my folks came down, my main goal was to get the planking pieces rough cut. A full sheet of plywood is too much for one person to work with for any amount of time, and since I do a lot of this work by myself, I wanted to make it manageable. So dad and I rough cut the aft pieces - the picture above is during part of that process. After rough cutting them, we spent a good deal of time getting them fit for length, as well as working on the fit around the centerboard case. We worked the plywood a little bit at a time, which was the only way we could ensure a tight fit. Yes it's slow work, but there was really no other option. Because of the way the bottom angles down toward the transom, it has to be sprung into place - this springing means that the planking will actually be a bit proud if you were to lay it on top of the transom. That's why you have to go slow and remove material in small amounts. As it turns out, we got the port side piece almost perfectly fitted, and the starboard piece was pretty close. (It just needed a little additional work, which I did after my folks left.)

Compared to the aft planking, which lies somewhat flat on the boat, the fore planking requires a lot of working before it's fit. The main reason for this is that there are two transition points - one point is on the chine, where the planking moves from a lap joint (aft) to a butt joint (forward), and the other is at the stem, where the planking moves from a butt joint (aft) to a lap joint (forward). Here's what I'll say about these joints - I chose these points somewhat arbitrarily, based on the instructions and the book. I placed the chine transition point halfway between frames # 3 and # 4, and placed the stem transition point just forward of the transition point between the keel and stem. I spent a lot of time thinking about the placement of these points, only to realize that I should just pick them and move forward. I suppose you could get philosophical about these choices, but it's a boat, not a painting. Get it done.

For the forward bottom planking, I first fit the port piece in place and glued it in. I used the chalk method of transferring the line of the side planking onto the bottom planking. (I used sidewalk chalk - you can get a box of this for $1 at a craft or office supply store.) I was first afraid that the plywood wouldn't bend sufficiently, but it took the curves with no problem. When I glued and screwed the port side forward bottom planking in place, I made a mistake. I started at the bow and placed a screw at the 'point' of the planking (e.g. the most forward point of the planking), and then moved back, placing screws alternately in the stem and chine. When I got to the end of the piece of planking, it turned out that I had a gap of 1/16" along the chine. The reason this gap appeared, I think, is that I didn't properly secure the forward part of the planking before moving back. In addition to the screw at the very forward end, I should have also placed a screw in both the stem and chine, 8 inches or so aft of the point. (I had already drilled out these screw holes when I was dry fitting the piece, and could have simply driven the screws at that point. Turns out, I should have done that. I think I ended up 'crumpling' the piece of planking much like you might crumple a piece of wrapping paper. The distortion wasn't huge, but it was enough to leave a sizable gap along the chine which will now have to be filled with epoxy filler.)

Bottom Battens

I'll start off by acknowledging that I'm not a good blogger, in the sense that it takes three months between updates. My apologies, and thanks for continuing to read.

Now that that's out of the way, I'll move on to the next step in the building process, which is the bottom battens. As mentioned in the last post, when Mike was here, we did some work pre-fairing the battens, especially toward the bow. There's a lot of extra material in that area of the battens, and we removed it to save some time later. I suppose it doesn't really matter when you remove the material - before or after installation - but you'd probably end up re-countersinking the screw holes if you were to do all the fairing after gluing them in place.

Here is a picture of the battens during the process of fitting them. I've got a couple clamped in and am checking spacing, bending and their general fit:



The idea with the battens is that they support the bottom planking and also (obviously) help determine the general shape of the hull. It's important to have contact between the battens and the planking at all points. This is generally true with this boat, though there are a couple of points where I had to rely heavily on epoxy to make things secure.

Here's a great picture of the battens as they are being glued into place. In case you didn't believe previous posts, I do in fact have a ridiculous number of clamps:



The hardest part of this process was finding a good place to clamp to, especially considering the wax paper I had to use at the wood-clamp interface to prevent the clamps from becoming a part of the boat. For those of you building this boat, let me tell you this - after you glue and screw the battens in place, you'll have to fair them. At some points, you may end up removing a lot of material, and may need to resink your screws so that the screw heads remain below the surface of the batten (and thus remain out of the way of your plane blade). So, when you first glue these in place, make sure you have a strategy for being able to remove the screws once the glue is dry. I suppose there are two ways to do this: 1. don't use any screws until the glue is cured, or 2. make sure you countersink the screws deeply if you use them while the glue is still wet.

Here's the 3332 shop's best and most beautiful assistant: