Bob

Bob
Framed in laminated Vendia; fastened with copper nails and roves

Monday, 2 March 2015

Bob's Bin Framed

Bit of an experiment this, but it worked fine. Five frames, laminated from three layers each of 6mm Vendia, making an overall 3/4in x 1 1/8in, which were then notched over the keel and riveted in traditional fashion.

I was a little concerned that by using the moulds as the jigs from on which they were laminated, the curve would be to the inside, but in the event  there was plenty of spring and give in the finished frame to accommodate both this and the twist in the fore and aft frames. The three middle ones went in easily. In fact, apart from the time taken laminating, the process was quick and stress free: no juggling hot wood and, crucially, the frames could be sealed inside and out before fitting. It is impossible to prime or seal steamed timbers, to their long-term detriment. I am confident these will last for a very long time.


The frames once fitted the shell has stiffened accordingly and once the gunwales are in, even more so. These will be the only nails used, apart from to fasten the gunwales, and I think give a bit of character in an otherwise all-glued hull. A combination of new and old techniques, which appear to work well in this case.




Wednesday, 18 February 2015

Framing

With Bob set up level, it was time to take the first shot of how she might sit on the water. Cleaned and sealed, I laminated the frames at stations 3, 6 and 9 using the moulds.
 

The frames, made up from three laminates of 6mm Vendia (3/4in x 1 1/4in) were flexible enough to conform nicely to the hull, even though the radius taken from the moulds would have been marginally greater. With 12 plies going one way, and four the other way, within the three layers of  Vendia, it is no surprise the frames were stiff, yet retained enough flex to allow them to be twisted into the bevel of the hull at stations 3 and 9.



Station 6, where the hull is flat to the frame, was a doddle. There will be floors at mid stations to take the slatted floorboards, probably mahogany.


Tuesday, 17 February 2015

Turned and Sealed

Talk about light: two of us could have balanced her on our heads. And now she's upright it's a chance to admire Mr Gartside's lines.

The Collano excess that I could not reach to remove when wet was easier than I thought to scrape off using a chisel along the lands, followed by block and paper. I believe the result is infinitely nicer than the mess you find when you turn over an okume ply/epoxy boat. What you see in these photos is pretty much what I saw when the boat was turned. After which five hours or so of cleaning up and sealing with International two part clear sealer.

The stems are laminated oak, glued side to side with staggered scarphs. Because the inner stem (apron) was made from a template which precisely matched the outer stem template, with careful bandsawing the stem pieces fitted near perfectly with minimal fairing. But it's a tricky business fitting a curve to a curve and you can see why laminating is often preferred.


As to the shape, in clinker some of the extreme flare has been smoothed out, which is why I like the method: it just does what it wants to, departing ever so slightly from the moulds where it really cannot be bothered to conform to the moulds. And it will take over even more if you don't keep a firm grip. There was, for instance, a little more flare just forward of the sternpost.


The laminated Vendia frames, three ply, 3/4 x 1 1/8in, at stations 3, 6 and 9 will hold her shape until the gunwales go in later. For now it's a case of sealing and making a start on the interior, starting with the frames and gunwales.


The hull is very flexible at this stage and will need supporting. One coat of clear sealer


Thursday, 5 February 2015

Planks (More Thoughts)

Jan, who commissioned the Gartside skiff I am building and about whose appearance I have been agonising over,  sent me a link to this photo, of a class of clinker dinghy they sail in the Netherlands as an example of the different ideas builders have about the line of planking.


To my mind the dinghy on the right looks pretty awful, and yet it is leading the fleet, so either the helmsman is good, or the planking makes the boat fast. I hope it's not the latter as all conventional wisdom about "if it looks right..." goes out the window.

The boat on the far left looks OK, and the middle boat is, to my eye, the sweetest looking, although the ones in the background may be better. They are clearly slower than the trio in the foreground. Hmmm.

I suspect the leading boat was amateur built, and good for whoever it was. He's either built himself a rocket ship, and to hell with good looks, or is a demon helmsman. I don't think, however, his idea of a fine line will catch on. Better a slow, but good looking boat, than a fast ugly one? But then look at Myth of Malham, a rocket ship from the 1950s that most people thought ugly. They also thought Britannia was ugly too, when launched in 1893.

But they were smooth sides, carvel. I think it's different with clinker, where the eye immediately notices any discrepancies in the lines of the planks. And the ones in the dinghy on the right are pretty wild.


Wednesday, 4 February 2015

Last One Up

Well, that's the last plank on, Next it'll be a case of laying a batten round the sheer and trimming. From the photo you will see it needs a shave off the aft section, (that's to the right of the photo) between station 6, midships, and 10, and maybe some minor tweaking elsewhere to make it sweet.


I left the last plank slightly over width just for that reason as you can take material off, but like a bad hair cut, you cannot put it back. Trying to get the sheerstrake right I felt a bit like that fellow who cleaved the Koh i Noor: lots and lots of squinting and measuring (though not years, as in the case of the diamond cutter) before committing wood to saw.

Tomorrow it's clamps off from the starboard side, a good sanding and another coat of clear sealant before thinking about fitting the oak stems and keel. The owner's up next week, so I might even tidy the workshop... After which it'll be time to turn her and think about how to go about fitting her out, based on Paul Gartside's drawings.


Wednesday, 28 January 2015

The Perils of Lining Out


My best to date: Florence Oliver, but look at the third strake down from the stern. Flare makes it look narrower than numbers two and four. It's not. But what about when Florence Oliver heels? All will become sweet.
What is the secret formula that will ensure a perfect line of planks in a clinker boat? Well, some people simply divide the moulds into equal parts, depending on the number of strakes. That doesn't work, so don't try it. You are likely to get a nasty hump aft of the bow and stern. Somehow you need to damp down the enthusiasm of the planks to rise too quickly at those stations.

How about dividing the midship mould in equal parts, and the bow and stern posts similarly, and apply some sort of rule to the stations aft of the stem and forward of the sternpost? Say, at stations 3 and 9? Maybe increase the widths of the planks gradually, until the last three in an eight-strake boat were more or less equal width?

Would that work?

Close, but the sheerstrake needs to be perhaps 1/4in narrower at the stern, to give it a little flip, which entails the second strake down being a bit wider, and so on down.
Probably. And it would be nice to have a programme that calculates such things, but I am not a designer. So, without the benefit of a kit of parts, computer cut from the designer's drawings, you are on your own. Especially when the boat you are building, in this case a Paul Gartside 16ft Bob, is drawn for strip plank. Every strake has to be spiled, which means to a large extent it's all in the eye.

But where is your eye? From a fish-eye view, or from just above the waterline? At waterline, or 6ft above? And if your sections are flared fore (or aft) then a 4in wide strake will look narrower than a 4in strake without flare. And what if the boat is a dinghy that habitually heels to 30 degrees or more? Then that sweet (suet as they used to say) line flattens and even reverses into what they call sny (a nasty word for a nasty look, although suet-looking in a coble).

It all goes to show that building in clinker without the benefit of drawings with plank lines marked, from a genius like Mr Oughtred, Vivier orGartside, is perhaps the hardest discipline. Carvel, you can get away with stealers and such to finish off a hull, and strip plank is no more than wood cored epoxy and a very very nasty way of building a (nice) boat. Slap them on, fair them off, sheathe them and you wouldn't know what the core looked like. With clinker the innermost soul of the boat builder is cruelly exposed.

So, the answer is to use and trust your eye, and batten each plank out before you spile. And agonise, and measure and measure again, and still you may not get it spot on.

I make no claims that I have cracked it in the skiff I am building. So far so good. Much will depend on that vital sheerstrake. And only then will I know if I have managed to pull off anything close to the perfectly lined out clinker boat. The closest so far has been the sjekte, Florence Oliver I built a while back.

Friday, 23 January 2015

Progress

The sixth strake took a bit of head scratching to get right, but eventually it came good with a lot of battening and squinting and tweaking. It helped also to take reference photos which can be blown up on the computer, and which show up any major discrepancies in line.


The last three strakes are pretty critical for overall looks, so there's no point in rushing things. As always the Vendia/Collano method is a joy, but it is important to clean up as you go along. Collano sands well, but the less the better. Being a little softer than epoxy it has much the same consistency as the Vendia, they sand equally which avoids making divots in the wood. And once set hard it can be chipped away much easier than epoxy which needs the hot knife treatment.

Photos as always show more than words, so here's how I left Bob this afternoon.