Monday, 27 July 2015

More bench making

I've been off work on holidays for a week, and thought I'd be able to get the bench knocked over in that time. Turns out it's a project in itself. So far I've got all the timber cut and dressed, and now I'm starting to assemble the bits to create the frame:

That's half the frame. The end pieces are solid timber, and I'll put a 4mm odd ply back on the whole thing to brace it. I'll make the fixed shelves from 9mm ply, sitting on the 90mm wide Tassie Oak cross pieces. I'll add some holes in the legs for adjustable shelves as well.

There's quite an amazing amount of timber in this. So far the only metal bits are the adjustable feet, which are already coming in handy as my garage floor is a long way from flat. I've used about 150 little dowels so far.

The other thing visible in the photo is the complete shambles aboard Elena. I'm hoping that once I have more storage places in the garage there'll be rather less crap left on horizontal surfaces.

Monday, 20 July 2015

A diversion for bench-making

I've been gnashing my teeth lately wondering how best to support my mast and boom while gluing up the staves. I tossed around a bunch of ideas; buying a bloody big plank to clamp everything to, buying some steel or aluminium RHS... Each of these options is moderately expensive and I'm left with a bloody big lump of wood or metal that I have no idea what to do with, and that will be difficult to store.

Rather than a quick jury-rigged solution, I thought instead I could build a nice spar bench, on which I can build the mast and boom, and which would be a useful piece of furniture in it's own right, giving me a place to store a whole pile of stuff that rattles around my main bench and floor, and giving me a really nice work surface in addition to my main bench.

So the spot that's good for this is across the back of the garage. It's about 6.5m, and will allow me to house a bench a little over 4m long, most of the length I need for my 6.1m mast. If I build it the same height as my existing bench (930mm) then there's always the possibility of butting the two up and doing some levelling to get a 6.3m long flat surface, at least temporarily, and with the aid of a forklift or small group of weightlifters...

Alas I can't build a really deep bench in the spot chosen, as it subtracts from the length of the garage, and I've only got about 900mm between Elena's transom and the wall when her bow is just inside the door. So I figured 450mm deep would be adequate, and knocked something up in sketchup:

A nice solid Jarrah top, Tassie Oak framing, and sides, back and shelves in ply. The gaps across the top will accept 450mm wide by 400mm deep drawers, and there's some useful cupboard space underneath. For now I'll build it open as in the drawing. I'll add cupboard doors and drawers as finances allow.

Here's a start on my legs:

They're made from 90x19 and 42x19 Tassie Oak, joined with a mortise for lots of strength. I'm adding adjustable feet so the whole assembly can be really accurately levelled.

The timber for the bench top is gorgeous. 150x19 Jarrah planks. Mogget thinks they're a great idea. I'll laminate them onto a couple of bits of 19mm thick ply, for added strength, then add a lip on the front for face clamping. I confess I did ponder building a 40mm thick solid Jarrah bench top, but couldn't justify the added expense.

Sunday, 5 July 2015

Bowsprit

The bowsprit John recommends for the Navigator is a 100 x 40 plank, tapering to 40 x 20 at the front.

I think that's boring, and not nearly pirate enough for Elena. So I figured I'd do a more traditional round bowsprit instead. This will go nicely with a neat Davey 2 eye cranse iron at the front for the bobstay and jibstay attachment. I'll bend up some bronze plate and fashion my own gammon iron and heel.

In any case, I bought some Jarrah and Tassie Oak, tapered the Jarrah from 22 thick at the back of the sprit to about 10 thick at the front, then laminated the three together. Once it set up I went at it with the power plane to make a 60 x 60 square tapering to 40 x 40 at the front.

Then I marked it up and turned it into an octagon with the power plane and my Stanley no. 7, then used the no. 7 to make it 16 sided. Finally I used an 80 grit belt to round it out by hand.

Here's what it looks like temporarily on the boat. There's no way I'm closing the door with that attached.

Oh, the top plank is painted with one coat of Toplac "Donegal Green". I'm quite happy with the look.

Sunday, 28 June 2015

Chainplates

My chainplates arrived during the week, so I set about attaching them. The mob I bought them from, classic boat supplies, were out of 1/4" countersunk bolts so I substituted 5/16" ones. Anyway, these puppies aren't going anywhere.

They go under the outer gunwale, in a slot machined specially for them. I drilled three 8mm holes through the hull on 45mm centres, and passed the bolts straight through. I even polished up the bolt heads. They're beautiful castings, and solid as a rock.

At this point in the plank there's a doubler under the hull, so it's 12mm thick rather than 6mm. To spread the load a little I machined up some 2.4mm thick bronze plates to go on the inside, so the hull is clamped between chunks of bronze and the bolts can't possibly tear through. If the load is big enough to take the chainplate out, quite a bit of hull is going with it.

Now that the detail is sorted for the gunwales, I epoxied them in place. I put a bunch of clamps on in addition to the screws to ensure there's no gaps.

Here's a photo showing a lash-up of my proposed shroud attachment. The holes in my chainplates are big enough that I think I can do away with deadeyes or blocks on the bottom, and just use the chainplate as a deadeye directly. I run a 6mm line up through a little Harken 29mm double "carbo" block, which weighs nothing and has no metal in it. I can splice the end of the shroud directly to the block. Here I've just tied it to a length of 4mm braided rope.

The other end of the 6mm line goes aft to a 100mm bronze cleat. This is probably massive overkill, but I have a bunch of these kicking around having decided to go for bigger ones in the spots I bought these ones for (halyards and mooring lines).

In any case, playing with it here it was really easy to set up and adjust the shroud tension. I imagine it will make stepping the mast quick and easy, and plan on doing exactly the same setup for the bobstay.

Saturday, 20 June 2015

Finished the decks.

Over the weekend I put the last couple of deck pieces on, at the bow on the starboard side. After gluing the front piece down, I cut a hole in it so I can access the anchor well and added a little bronze flange as a scupper for the anchor well.

This is only on the starboard side. There's nothing on the port side, so I'm a little concerned that Poseidon will notice Elena only has one eye and will sink us for bad Feng Shui. If I obsess too much about it, I've got another bit of bronze to add a scupper to the other side.

Mogget's taken residence in the anchor well, as expected.

The gunnels are held on with screws at 480mm centres. I haven't glued them down yet, as I'm waiting on chainplates, which will be sandwiched between gunnel and hull, so I need to make a slot in the gunnels to clear the chainplates. I think I'll skip the rubbing strip at the bottom of the top plank. I think it looks nice with just the gunnel, and am happy to carry fenders to protect the paint from docks etc.

I've been doing a bit of bronze work of late, turning a pin for the mast pivot and finishing out the centerboard lifting tackle. The lifting tackle consists of a sheave on a 6.35mm stainless pivot, with a couple of bronze plates and some more stainless to make a becket. I added 4mm stainless countersunk screws to the end of the pivot to locate it in the centerboard. These are thus far the only metric fasteners on the boat.

I've got a high zoot-factor Ronstan "orbit" 40mm double pulley up the front, with a dyneema lashing holding it to a nice old fashioned bronze eye. The mix of extremely traditional and extremely high-tech pleases the perv in me.

I really like this dyneema/spectre UHMW rope, by the way. Really like. I'm going to use it for all my standing rigging, so there will be no yucky wire.

Friday, 12 June 2015

Gunnels

If you've been following for any period of time you may have noticed I have a thing for Jarrah. Jarrah is a dense, rich, red west Australian timber, that's practically indestructable and looks really beautiful. I've done my transom in Jarrah, I've done my rowing thwart in Jarrah, and I'm using it in my mast. I really love the stuff, because it's quintessentially WA.

So, Gunnels. What better timber to mount your guns to than a length of lovely strong rich Jarrah. Easy! Off I went and bought some lengths, in 19x40, reasonably close to the 20x40 recommended by the erstwhile John Welsford.

Did I mention that Jarrah is tough, and dense, and strong? Oh, I already did, didn't I. Well, you can add stiff to that. I joined bits to make a 5m long length and tried bending it onto the boat. No way!

That prompted a week or so in the moaning chair

So then after I got over myself I tried with some Jarrah of slightly less heroic proportions - some 12x30 that I've bought for the mast. Easy peasy, but it looked a little wimpy.

The hardest bit was the stern, doing the upwards bend, not the inwards bend at the bow. Stiffness increases with the third power of depth, so the change from 40 to 30mm dramatically influences the stiffness. So I knocked my 19x40 down to 16x32, and tried again. Bloody hard work, but it went. Here's a photo of the first test-fit. I have to cut the bow end nicely and wait for more goop to arrive before I put it on properly.

Here's the join - knocking the length down from 19x40 to 16x32 made my join all but disappear.

I'm rather happy with that.

Sunday, 7 June 2015

Daydreaming

I'm vaguely thinking of what to do after I finish Elena. Somewhere in there is building a house for Perry and I to live in, and then once that's done I'd very much like to build a boat to seriously sail in. Elena has me all fired up on wooden boats, so I'm looking around at possible designs for a 26-30 foot cabin cruiser. Not a fast boat, but rather something we could sail around Australia in or even cross the Tasman.

Like I said, daydreaming.

A boat that ticks a whole lot of the boxes is the Herreschoff H28, a design that's stood the test of time and is much beloved by those who build and sail them.

As it's quite an old design, some of the plan details are actually available on the web. Most notably the offsets, which detail the shape of the hull in three dimensions. I've spent some time over the last couple of weeks transcribing the offsets onto the computer, converting them to metric, and then using sketchup to loft a 3D model from them. Here's a few views of my model thus far. As with Elena, I hope to use this model to try things out, like interior accommodations etc.

Edit: Here's a view of the working that I used to loft this design. I started by drawing the cross shaped former, which I put on it's own layer so I could easily turn it on and off. Then I made a moveable "frame former" on which I can draw frames. I have lines at the station points on the initial piece, and move it around to draw the various lines from the offsets. In each case I move the former so that either a horizontal or vertical surface is where I need it, and rule offsets onto that. Then I use the 3 point arc tool to connect offsets and make fair curves, effectively interpolating between the offsets. Some mucking about is needed to ensure everything is fair.

Once the specified lines are drawn, I then slide the frame former to various points and draw smooth frames, by selecting the points where the lines intersect my former, again using the 3 point arc tool to interpolate between lines.

The frame lines now give me more points so that I can interpolate more WL+n lines. I do this every 4", or 101.6mm.

Finally the really tedious bit is drawing a huge pile of triangles to sheet the hull. Once the lines are drawn, they get selected, then the properties changed to smooth the hull over them. You can see I started with a 101.6mm grid at the bow, but got sick of it about 1/3rd of the way along the hull and swapped to a 203.2mm grid.

Sunday, 24 May 2015

Do you think my workmates will notice...

Last time I had my hair done, nobody at work even noticed, and I was a bit put out. I'm hoping this time it will be different.

My hair's been going seriously grey over the last couple of years. I have previously dyed it; I spent much of my twenties with my hair a variety of shades of red or auburn. I went out on the town with a mate a month or so ago and saw a chick with bright blue hair, and thought if I ever get the courage, that'd be awesome.

So, I'm turning 44 in a few weeks, and I'm working my way up to a proper mid life crisis. I don't have the dough to blow on a sports car, so the blue hair will have to do the trick.

The recipe I followed is two applications of 30 vol bleach, then paintbox "blue velvet". I'm not expecting it to stay vibrant for terribly long. Once it's faded I might try a purple, as that's traditional for women in engineering.

Edit: and after a fortnight, I went totally to town. Thanks Mary!

Saturday, 16 May 2015

Mogget and daddy's adventures on the high seas!

I've been decking of late. It's straightforward - cut pieces out, glue them in. The only reasonably complex bit was the bridge on the aft end of the deck. I steamed a couple of bits of 8x18 Tassie Oak in place to form a nicely shaped arch to support the aft end of the deck, then buttered them up and put the aft deck in all at once.

Once I've done the coamings, I'll make up a radiused piece to go in the corner here, as I don't much care for the sharp corner.

So now that enough deck is in place to try it out, I thought I'd mount up a rowlock in it's final position (on a 6mm coaming piece, and 18mm above the deck) to see how that works for rowing. This is where Mogget was very keen to help. Clearly we're going on an adventure, and he's got to be involved.

Perry's modelling the "oars down" position, with a 2.4m length of timber pretending to be an oar. Even with quite a short bit of timber, it looks like the ergonomics work reasonably well.

With the oar down, there's a little bit of clearance between the bottom of the oar and the edge of the deck. This is with the rowlock on 18mm of coaming. To ensure clearance between the oar and gunwale, I can either extend the oar (perhaps to 3m) or raise the rowlock. Either should be straightforward, but I'm keen not to have the coamings too high, as I just know I'll want to sit on the decks.

In the next photo I've asked Perry to put the oar on his knee, to ensure the tips of the oars can get out of the water. He's sitting with his knee fairly high, which isn't quite right, but even then the tip of the oar should be out of the water.

Finally here's a photo of the rowlock in the down position. I think they look quite nice. For reference, I've got the rowlock centered about 10cm aft of bulkhead 6. That puts it about 60cm aft of the front edge of the rowing thwart.

Sunday, 3 May 2015

Bow eye

Working with bronze this week. I didn't much care for the look of any of the bow eyes I could buy, so modified a double clevis chainplate fitting to suit. The double fitting allows me to connect the bob stay and still have a spot for towing the boat and pulling it up onto the trailer.

It started looking something like this:

I needed to narrow it down to fit on the stem, so hacked the sides off. While I was at it I cleaned it up some. This is what I ended up with. It'll darken up some with age - at the moment it looks rather ghastly pale:

To give an idea of size, it's 115mm long. The wood screws are 3" 18 ga, and the bolt is 3/8". The plan is to drill a hole in the back of the fitting, turn the end of the bolt down some to fit, and either silver-solder or TIG it in place. I haven't decided which yet - the bronzes are not the same - the fitting is manganese bronze while the bolt is silicon bronze, so TIG may not be appropriate. I might try with an offcut first to help decide.

Next I turned the head of the carriage bolt down and turned an M8 thread into it, then bored a hole into the back of the eye, which I tapped M8 to match.

I assembled it with some flux and ran some 56% silver into the thread to hold it nice and tight. I'm confident the bolt isn't going anywhere.

Finally I polished it up a little and installed it on the boat, using sikaflex as bedding compound. Here's me showing rather more plumber's crack than is seemly, wishing my arms were longer and doing the nut up in under the anchor well:

It's additionally held to the boat with two 18ga x 3" screws, so is nice and solid.

And in context:

I reckon that'll do nicely.