Monday, 7 July 2014

Garboard plank and building frame

We went and bought some more sheets of ply. I rearranged things in the garage a bit, and cut a 10:1 scarf into four sheets with my no. 5 plane. Another big workout. With all this boatbuilding, I'm going to end up with an upper body like Schwartznegger. Although it's hard work, scarfing is actually pretty simple. With ply the layers of wood guide you.

Next step was to build a building frame for the boat. This was just knocked together with framing pine. It took a while to find two lengths that were acceptably straight for the side pieces. before the boat went on I used the building frame as a huge workbench to prep the double length scarfed garboard plank.mMogget sees it as a huge cat climbing frame.

Here's another view of the frame. Don't look too closely at it. It's rather rough. It's flat and square though, and nice and strong with six legs being braced in all directions.

So here's where the fun really begins. I marked up the garboard plank with John's offsets, used a stringer to draw a fair curve, and cut it out with a jigsaw, finishing with my plane to get a really nice smooth curve.

Then I cut a hole in the middle for the centerboard slot, and offered up the rest of the boat. Much grunting ensued with this two-person lift. It took three tries before the centerboard slot was just the right size. To celebrate having somewhere to put my motorbike again, I tidied up the garage a little.

Next step is to put the proper reference height pieces in at each of the stations to form the curvature of the bottom of the hull, then glue and screw the garboard plank to the keel plank. Then I'll add more bulkheads and install some stringers and seats.

Sunday, 22 June 2014

Cutting pieces of wood and gluing them to other pieces of wood.

This weekend has been pretty busy. Basically I joined bits together with epoxy, so now I can barely lift the boat.

I started by using a scarf joint to join a couple of bits of 90x19 Tasmanian oak, that'll be my keel plank. Scarf joints have been used since their first appearance at the Melbourne Cricket Ground in the eighteen eighties... Anyway this is a 6:1 scarf, and makes my two 2.4m planks one 4.8m one.

I was careful not to clamp too hard, to get optimal squeezage. That's a technical term. A quick bit of planing, and it looks quite nice.

While waiting for epoxy to go off, I joined all the bulkheads I've made to the spine, and attached the centerboard case as well with screws. I also added bits of 19x19 Tasmanian oak as bracing.

Then I cut a huge slot in the keel plank for the centerboard to poke out of, and screwed that to the spine/centerboard case combo. Mogget is impressed.

It looks kinda cool now, with the centerboard poking out.

Friday, 20 June 2014

It floats! Is that a good thing?

So today I took my centerboard down to the boatramp and launched it :P Alas I totally forgot the champagne!

Bad news is it floats. Good news it it really wants to be the right way up, with the tip pointing down. It's only the bit above the pivot that sticks out of the water.

What to do? I presume it'll be okay, and the buoyancy at the top of the board won't be a problem, as that bit will be out of the water normally anyway, right...

It's incredibly easy to pull through the water, for what it's worth. Leaves barely a ripple on the surface.

Monday, 16 June 2014

More centerboard work, plus centerboard case

So here's the centerboard all nicely shaped. I added an uphaul pivot, made with two pieces of jarrah that sandwich the centerboard. It's held together with epoxy plus four 38mm 8G silicon bronze screws, so it should be nice and strong. I routed a nice big 20mm wide slot to accept either a sheave and metalwork for a becket for a 3:1 uphaul, or if it's still hard to haul up, a pair of sheaves for a 4:1 uphaul.

Next I made it look ugly by laying lots of 200 gsm unidirectional carbon fibre on either side. This stuff provides the strength. Not shown here (I forgot to take a photo) is a strip of 400 gsm fibreglass tape down the leading edge and across the tip, with a second piece at the tip of the leading edge.

Then I faired it. I used much the same epoxy mix that I make for gluing, with enough glue powder to make a peanut-butter consistency. I slathered this on with a spatula that I stole from my kitchen, and then after curing I removed most of it with some 60 grit emery in a sander. Then I repeated the exercise, with slightly runnier goop.

Once I was reasonably happy with the shape and surface, I bunged a coat of undercoat on. Once this is dry I'll remove most of it before doing a couple more coats and a couple of top coats. Also shown here is the case, which is framed with 19x42mm Tasmanian oak, and held together with no less than 48 8g silicon bronze woodscrews.

The pivot is only temporary. I've been testing how it works with an M10 bolt. I've got some more bronze on order to make a proper pivot, using a 12mm bolt to clamp a 19mm tube, with some 25mm OD flange pieces epoxied into the centerboard. I'll show details of that once the materials arrive.

Monday, 2 June 2014

Shaping the centerboard

I know I only glued the laminations together yesterday, but today has been a pretty big one, so I thought another post was the go. That and Perry told me that I really should stop working before I fall over :)

What a great cardio workout! I've found the perfect antidote to tuck-shop lady arms, in the form of my nice Stanley no. 4 plane. I tried my new no. 5, but found the extra weight harder to work with, so went back to my no. 4. It all started innocently enough. I cut out the profile of the board, and planed the board nice and smooth, then ruled some center lines down the board and started removing material from the leading edge:

After about eight hours of planing, my workshop started to look like a bomb had gone off:
The secret to successful planing is to remember to sharpen the plane iron often. Every time I started to get tired, I'd run the iron over the whetstone while I had a break, then when I went back to it it was easy again. I think I sharpened my iron about five times today. In terms of effort, I feel like I've just ridden about 80km. I'll sleep really well tonight.

So I reckon it's about 80% there. I went at it with some 80 grit emery to smooth things out, and it's looking pretty good. I think on payday I'll go buy myself a power sander. Note the extra little bit of Jarrah at the bottom of the leading edge. This is the area where I think the board will cop the most knocks, so I wanted it extra strong:

Check out the shavings. Planing with a proper hand plane like this is a lot like sculpting. The wood knows it wants to be a foil. You and the plane are there to help it achieve it's goal. It's pretty obvious where the non-foil bits are, so you work the plane over them, and it gets gradually closer to shape. Very rewarding.

After a day's work the profile is looking reasonably foil shaped. I have lots of motivation to remove all the unnecessary material. Otherwise I'll have to add more lead to get it to sink, and I really don't want to resort to that:

Once the shaping is done I'll add some of this stuff. It's unidirectional carbon fibre tape, and should make it reasonably hard to break:

Then do the pivot hole and the lifting bit, and this part's knocked over :)

Sunday, 1 June 2014

Fun with epoxy

My epoxy arrived through the week, so I'm making the most of the long weekend, and getting it everywhere.

Here's how I'm doing my centerboard - the lead hides in a routed out pocket, so it'll be surrounded by cedar. I'm hoping this will make the board easier to shape into a foil, rather than shaping, then cutting a big hole, adding lead, and fairing:

I did the laminating in three steps: The front section with the lead brick, then the back section, then I joined the two and added the leading edge jarrah piece. This allowed me to make better use of shorter clamps for the springier small pieces of timber. Here's the start, taking a deep breath before mixing epoxy:

And after gooping everything together:

Then finally the whole centerboard, after repeating the exercise for the rear bit and adding the leading edge:

While I was waiting for epoxy to go off, I joined doublers to bulkheads. At one point every one of my 27 clamps was being used. I think my building speed is limited by number of clamps and available horizontal surfaces. How many clamps do I need to build a boat anyway?

I quite like the bote cote epoxy. It's easy to mix and doesn't stink the house out. It's certainly refreshing doing woodwork after that awful lead interlude.

Sunday, 25 May 2014

Restoring tools and making sausages

Two very different topics this week. Alas I've been out bush for much of the last fortnight, plus my epoxy is yet to arrive (buying stuff from boat supply places + shipping to Geraldton = much time waiting for stuff to show up).

So the first topic - restoring tools. Years ago I had a lovely old Stanley Bailey 4 plane. Very much standard issue, reasonably good quality, small enough to use one-handed but with enough heft to remove serious amounts of timber. I lent it to a mate and then promptly moved across the country, so it's his now. My centerboard is going to need plenty of planing (as are lots of other things on the boat), so I went looking for a new plane. I ended up buying a number 4 from ebay - probably older than I am, with proper rosewood handle and tote. Looked pretty well loved in the photos.

So once it arrived, I spent an enjoyable weekend restoring it. The handle and tote were rubbed back and got a few coats of varnish, showing the grain wonderfully. The blade, which was well rounded over, got a patient sharpening on my hone. For good measure, I went at the sole and sides with the hone as well, to remove some of the corrosion and scratches. If you're ever wanting to flatten your hone, spend a few minutes working the base of a plane on it - it'll very quickly become flat. Once much of the corrosion and scratches were taken out, I put a piece of 400 grit wet and dry on a flat countertop (okay, my kitchen bench) and polished the sole up so it's beautifully flat.

The result looks lovely, and is a delight to use, just like a plane should be. Of course now I've clicked buy on a number 5, and am eyeing number 7's...

Next onto the sausages.

I've decided I want a weighted centerboard. Not massively heavy, just enough weight that I won't need an uphaul. I figure around 5 kilograms of lead will overcome the buoyancy of the board and ensure it sinks nicely, without ending up a pain to work with. So I went to Bunnings to buy lead flashing. Turns out the stuff is revoltingly expensive. They wanted around $60 for a 5 kilogram sheet of lead flashing.

So I figured it'd be cool to recycle a battery for the lead. I've got a never ending supply of dead batteries, so I grabbed a ten kilo one and went to work. This is where everything turned to custard.

Turns out lead acid batteries are mostly lead oxide, which is completely useless. I opened the case relatively easily, and then neautralised the acid with sodium hydroxide until it was neutral and safe. Then I extracted the electrodes. Inside a battery is the most disgusting, filthy black mess you've ever seen. Most of the electrodes are lead oxide paste, held in a skimpy mesh of lead, with lead interconnects. Getting the lead oxide paste separated from the lead mesh was really no fun. Never again - my marriage just won't sustain the aggravation. Once done I had a paltry two kilograms of useable lead, for about four hours of the most disgusting work I've ever done. And now I've got about 8 kilograms of lead oxide that I have no idea what to do with.

So rather than waste my time and sanity on more batteries, I caved in, went to Bunnings and bought a 3 kilogram sheet of flashing. This at least was relatively pure lead. I melted my 5 kilograms of lead in a crucible (aka old camping billy), skimmed the oxides off the top, and poured the lead into a mold, which I made by pressing a sheet of ply the right size into some beach sand.

More disappointment. The mess that came out of the mold was about the right size, but was icky and porous, with a very rough surface finish. Not very flash. I figured the only way forward was to work with what I had, peen the surface to press the mess together, and melt more lead into the worst of the holes using a blowtorch. Then more peening to get it to something resembling the right size and shape. Thankfully lead is super ductile, so puts up with this abuse.

So this is the result, after about twelve hours of pure, unadulterated frustration and cursing:

It's not going to win any awards, but it's about the right weight, and about the right dimensions to fit into the cavity I've made in my centerboard. There are no photos of the process because, like making sausages, it's best left unseen. Now I truly understand why people aren't keen on weighted centerboards.

Sunday, 11 May 2014

More bulkheads, mast step doublers and centerboard stuff

I'm gradually working my way backwards in a reasonably methodical way.

The next logical step after bulkhead 3 was to do bulkhead 4. I deviated from plan again, making it from a single piece of 9mm ply that goes the full width of the boat. I wanted the area around the front of the centerboard case and back of the mast step as strong as possible. To do that I knocked up a couple of doublers for either side of the spine between bulkheads 3 and 4, and added tabs to the front of them that pass through bulkhead 4 and into the front of the centerboard case. This will stop the centerboard case pivoting with respect to the mast step.

Here's the detail of the join. It holds together nicely even without epoxy. I'm hoping once it's epoxied and filleted it'll be nice and strong. I'm thinking perhaps adding some unidirectional carbon tape along bulkhead 4 once things are together could also be helpful, as bulkhead 4 transfers loads from the shrouds to the centerboard and mast step, so we want it to be as stiff and strong as possible.

Bulkhead 5 is almost to plan. The only deviation is to make the side seat 20mm taller and 20mm less wide. That gives a bit more space for centerboard case stuff, and reducing the width of the seat gives me a touch more room in the cockpit - think putting a sleeping bag on the floor and sleeping in the boat. I'm thinking I might make a removable slat floor to facilitate this without getting soggy, but that's a long way down the track. Incidentally my 12.7mm trim bit makes short work of duplicating pieces - just make one then run round it to make another. Alas bulkhead 5 can't support itself until I do the floor, so for now it's just neatly packed away.

I also made the arms for bulkhead 3, again using the trim bit to duplicate. This led me to find my first stuff-up. I'd got the measurements wrong on bulkhead 3, so one vertex was out by a good 5mm. After vacillating for a little while, I just cut a new piece from 6mm ply. Took less time to actually do the work than umming and ahhing about what I was going to do. I'm sure I'll be able to recycle the old piece into other things.

I cut the side pieces for the centerboard case from 6mm ply. The rest of the centerboard case will be made from "Tasmanisn oak", which I'm told is neither Tasmanian nor oak. Indeed I believe it's also known as Victorian alpine ash, which is Victorian but isn't ash, being a eucalyptus. Anyway, it's a good middle-of-the road hardwood. reasonably strong and durable, but without the weight of jarrah, and with nice straight grain. It's readily available locally in lengths to 3m. I'm thinking this will be my go-to hardwood for the boat. I'll use it for stringers, keel plank, keelson, etc.

So here's what the spine is looking like now, assembled as best I can without actually gluing anything together (I'm waiting on my first shipment of epoxy - what is it with boat supply places taking forever to fill orders?). The astute can see my first go at bulkhead 3 leaning against the wall in the background, and the rapidly growing pile of offcuts.

Last job for the weekend is to laminate the timber for the centerboard itself. I'm using western red cedar for the majority of the centerboard, with the leading edge made from jarrah. I'm told they used jarrah for the young endeavour, which is plenty strong. In any case it's the toughest timber I know of, and I'm sure it'll help protect the centerboard from dings when I run it into rocks etc. The western red cedar is incredibly light, I'm hoping it'll be reasonably easy to shape. Once it's shaped I plan to sheath the whole thing in unidirectional carbon to give it stiffness, strength, and impact resistance.

So after two weekends and a few evening's work, I reckon I'm up to 30 hours.

Sunday, 4 May 2014

Starting on bulkheads

Our cat Mogget is fascinated by the whole woodworking gig. He likes to be involved as much as possible, except when I turn the vacuum cleaner on. He gets quite enthusiastic at times, to the point of rolling in the wood shavings.

Here he is supervising cutting of some of the lightening holes in the spine. I'm using a circle jig on my router to do this, as it's of a size where that's doable.

I built the 6mm bits of bulkheads 1, 2, and 3, and slotted them into place on the spine. Here's bulkheads 1 and 2 on the spine. You can also see my lovely little home-brew speakers in the background, playing lots of really crappy eighties music:

Then I went to work on doublers. John's plan is very economical with plywood. The doublers are all made from multiple pieces, so you can make use of offcuts wherever possible. I decided that was fiddly, so I'm wasting plywood with impunity. Hence the doubler on bulkhead 1. The process I've settled on is to cut everything oversize by about 4-5mm with the jigsaw, then use the router to finish the cut. When it's a straight line I can use some timber to cut against. Ditto when it's a circle of appropriate size for my circle jig. Often it isn't though, so I just work these bits by hand with the router.

I'm not sure Mogget agrees with my wastage of ply.

Here's a close up of bulkhead 2 with it's doubler on top. The bulkhead itself is 6mm ply, the doubler is 9mm. The doubler is quite light.

It certainly becomes three dimensional quickly.

And one quick view of the model, this time showing the whole lot so far:

Thursday, 1 May 2014

The spine

On Wednesday I decided there was no way I could afford to do this (at least in a decent time scale) if I had to pay for freight for ply. So we borrowed a trailer and went to Bunnings, and bought four sheets - two of 9mm and two of 6mm. I have no idea what their ply is made from, except that it's stamped "BS1088" and had a brochure talking about sustainable forestry. On close inspection it looks pretty good. The face sheets are clear and I couldn't see any voide around the periphery of the sheets. It'll do. While we were there I picked up a pile of western red cedar planks that I'll laminate to make the centerboard.

So once I got home, I cleared the bikes and car from the garage, got Perry's help to put a 9mm sheet on the bench, and marked out the spine on it. Then I cut that out with a jigsaw, and repeated the exercise twice to make doublers for the front section. Then I clamped the three bits of ply together and worked them with my trim router (think tiny cuts) and sandpaper in a block until I was happy with the curves, and all three pieces matched nicely.

Here's what I'm trying to make, from my model. The spine is a good spot to start, because it's a manageable size, but a fair bit of the boat (bulkheads 1 through 3) hangs off it, so I can construct a largish subassembly that then gets attached to the rest of the boat before having to permanently banish the car from the garage:

Here's a pic just before picking up the jigsaw:

And here's the result of about four hour's work. I still have to cut the holes in the back of the spine, and slot it to accept bulkhead 3:

As I work I come up with things that I'm missing. The top two items at the moment are a decent plane and a spokeshave. It's very nice to actually be making things though.

Oh, and I've come up with a name for my boat. It'll be Elena.