2014-01-17

Post V - Tracing the plans

Not near as much to report in this post. I began tracing the molds from my full-size plans last Tuesday and it was a pretty slow process. Really fun to see all the station molds traced out individually instead of being laid atop one another like they are in the plans (see Figure 8). I am tracing my station molds on 3/4" MDF board. This was suggested in Van Leuven's book (referred to in Post III) instead of plywood because its edges are easier to bevel than plywood. Many of the suppliers of pre-cut CNC molds also use MDF, so I figure it's probably the best thing around.

I started by drawing a centreline for each station mold directly on the MDF. I used the factory edge for the base of the mold and dropped a perpendicular off that using a homemade compass -- a stick with a pencil driven through one end and a sharp nail driven through the other. For alignment I cut two little darts into the plans. One exactly at the intersection of the mold baseline and the cetreline, and another up near the top edge of the plans on the centreline. This made alignment with the CL I drew on the MDF much easier.

Figure 8: Darts cut in to centreline of plans


With the plans aligned, I taped the corners in place, and threw down a few sheets of carbon paper underneath the plans along the line I wanted to trace. Using a blunted nail, I freehand traced the sation lines, which transferred the line through to the MDF. Straight portions (like the recess for the keel and waterlines) were traced with a ruler. 

Figure 9: Use carbon paper to transfer lines to the MDF.



Finally, I ran over the traced lines with a dullish soft-lead pencil to get a nice bold sawing line. First session I only got 6 of 15 stations traced, plus the stem mold. It was a discouraging amount of progress but with my system figured out, I'm thinking next tuesday I can work faster and finish the rest.

2014-01-15

Post IV - Milling Strips

There are a lot of opinions out there on how best to do the strip milling. Some say to saw, then plane. Some say to saw only because you'll remove saw marks down the road whilst sanding. Some say  to pre-scarph boards and rip strips at full length and yet others say to scarph afterward. Some say to use bead-and-cove the edges of each strip for quick hull assembly, others say that rolling bevels (or no bevel at all) is perfectly fine.

It comes down to a tradeoff between beauty and time savings. I don't care much about the former and care a lot about the latter, so picking the exact method was pretty easy for me. First decision was to forget about scarphs. I'm not selling this boat and the look of mismatched butt-jointed strips actually appeals to me quite a bit. Structurally, butts vs. scarphs is irrelevant. It's also likely I'll paint the outside of the hull (at least the bottom) anyway, so time-consuming scarphs are off the table. Second decision was to go with a rolling bevel for edge-to-edge strip joining. This guy
gives a pretty convincing argument for using rolling bevels instead of bead and cove (unless you have a pro setup), and I'm confident with a block plane so I guess I'll do it that way.

This meant I could just use my clear 4/4 x 6 x 8ft rough-cut cedar stock, purchased from Devon Lumber in Fredericton, and mill it to 1/4" x ~3/4" without worrying about any extra steps. This was the only board dimension they have for clear cedar, and you have to wait awhile (they only run the cedar mill periodically) but as of right now I know of no other local suppliers that will do small orders.

On to milling the strips!

I didn't really know what my equipment was capable of (accuracy-wise), so I figured I'd try a ripping a few strips and see if I could get away with no planing. For sawdust-producing implements I have a crappy old skil table saw, with a thin-kerf blade and a homemade extension table:

Figure 3: Table saw with homemade extension


...and a really crappy shaky old band saw that I also made a base for (super safe with no belt guard):

Figure 4: Ultra-safe band saw


...and a 2nd hand thickness planer that seems to work pretty well even though the thickness reading is meaningless and the blades are a titch dull:

Figure 5: Slightly dull thickness planer


...and some more homemade items that include a sturdy table (at the height of the table saw) and an 8' straight-edge / ripping fence. These two clamp to the table saw to make a large outfeed + extended fence assembly.

Figure 6: Homemade ripping fence/straightedge (8' long)


As you can see, my power tools mostly are not very nice. After making just a few rips on the table saw I realized there was no way in hell I'd be able to consistently cut 1/4" strips straight up. I set the fence to 5/16" instead and decided to plane the strips afterward. This produced a much nicer result:

Figure 7: Top - Completed strips, Bottom - Completed strips from a new angle


I did ruin a few strips being hasty with the planer. If you try to put 2 strips through at a time, the thicker of the two (even if it is not very thick) will lift the feed roller off the strip surface off the thinner one. This means the thinner strip stalls mid-feed and chatters against the blade, making a terrible-looking wavy surface. Solution of course is to feed them through 1 at a time. This makes planing an agonizingly slow process, but on balance it evens out because sanding will take far less time

CAUTION:

Total time spent milling strips and figuring out the best setup for my equipment was 12 hours. Next time it would take half that at most...but there's definitely a learning curve.

There are a lot of cautions in the literature RE how long strip milling takes. Keep in mind I did the bare minimum and it still took a long time. If you're doing bead and cove yourself then expect to spend days and days at it. I just say this because if you're like me and are doing this on a vanishingly-small sliver of spare time, and you want pretty-looking full length bead-and-cove strips, just buy them. Better that than to get discouraged.

2014-01-10

Post III - Construction Methods

So after the design was picked out, but before I actually purchased plans,  I started thinking about ways to build it. There are a hundred different ways to put together a whitehall, but some are a lot easier to do than others. I looked around at available materials and decided to either go with a plywood lapstrake (like Fig1 in Post II) or a cedar strip monocoque hull.

For better or for worse, I decided I liked the cedar strip monocoque method. Engineering-wise it makes a lot of sense. Cedar/Fiberglass core-composite construction is strong, light and can produce virtually any boat shape. Hydrodynamically, the smooth hull wastes minimal energy generating turbulence and therefore minimizes skin friction. Lots of canoes are built this way but the method is perfectly sound for small row boats too. The popularity of core-composite construction means that information abounds on the internet and in published literature. Two references I used in my research:
are excellent. Moores' book is especially useful for understanding the overall technique and can almost be used as a step-by-step manual. The Van Leuven book repeats much of the same info, but has more specific discussion on the subject of rowing craft.

Intended use for this boat will be as a yacht tender on Grand Lake in New Brunswick, and in Passamaquoddy Bay. The shorelines in both of these areas are rocky, which brings up another advantage of cedar-strip construction. Fiberglass is abrasion resistant, and I can easily customize the amount of fiberglass on the bottom during construction, or add additional layers down the road if I find the bottom of the boat isn't tough enough.

Figure 2: Cedar strip construction - finished product on a canoe. Purdy!  



© Blue~Canoe Attribution-NonCommercial-NoDerivs License

Living in the Atlantic region, it's also relatively easy to get cedar boards locally, which considerably reduces the cost compared to shipping wood (or pre-milled strips) to my location.

2014-01-09

Post II - Looking at Plans

Plans plans plans, my god there are a lot of them out there. I had a few criteria when I started looking (in no particular order of importance).
  • Pleasing to the eye
  • Good rowing characteristics
  • Good cargo capacity
  • Ability to haul at least 3 people
  • Buildable in a 16' x 29' workspace
  • Relatively amateur-friendly
  • Good support from the seller
  • No hard chines (nothing against them technically, I just don't like the look)
After spending way too much time on the internet surfing designs and plans I finally came across this site:


and found what I was looking for - a Whitehall! It ticks all the boxes and looks good too. I really dig the 2 rowing position design as well. Most importantly, it's within reach of a first-timer. Don't get me wrong - I have dreams of mahogany runabouts and 450Hp mercruiser engines, but humble beginnings are where I'm at for now. I can't post pics of my specific plans (the ones from Canadian Canoes), but to keep my "no posts without pics" promise, here's an image of the Whitehall from wikipedia.

Figure 1: The Whitehall hull form. Nice!

wikipedia.org - public domain image

Friendly customer service from canadiancanoes, and the plans are more than adequate for building a whitehall. I just ordered the bare plans (wanting to do as much as possible myself), but the website will sell you anything you want to shortcut the personal labour - including a completed boat! They promptly responded to questions I had regarding modifications as well. I'd recommend them to anyone in the same boat as me (yuk yuk).

That's about it for this post. 

2014-01-08

Post I - Introduction

Here I will share my experiences in boatbuilding with the world. I'm not sure if anybody cares, but that doesn't make it any less fun to do.

Don't worry, I'm not going to bore everyone with walls of text either - in fact this is the only exclusively-text post I intend to contribute. If anybody wants to know more and trusts me to give "sage" advice, just contact me and I'll be happy to elaborate. 

Suffice it to say for now that I live on the Nashwaak River near Fredericton, NB, Canada and I am obsessed with building boats. I know this because it occupies my consciousness way more than any other subject. It is also a strange thing for me to be obsessed with, considering I've never built a boat and I have near-zero spare time in which to fuel my obsession.

Maybe I'm just obsessed with the idea of boatbuilding and nothing great will come of it except for new and colourful strings of curse words, but I'm giving it a go all the same! I've already arranged with my wife (obtained permission?) to be absent Tuesday nights for "Shop Night", during which I plan to retreat to my basement and construct the bits & pieces that will eventually fill this blog with posts.

So with the first post and intro out of the way, it's off to dreamland!