Bob

Bob
Bob with her seventh strake up. One more to go.

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.




Saturday, 17 January 2015

Strake Four. Half Way There

Progress is not exactly rapid, but now that Christmas and New Year are but hideous memories (not entirely true as this year for a change) Bob the Gartside skiff is taking shape by the day.


The fourth strake went on this morning and if I had more nippers, the other side might have gone on as well. But the downside with glue as against copper nails is that you pretty much have to wait for one side to dry before putting up the other, that is if you want to avoid fastenings. It makes for a slower but perhaps more measured pace. A pair of planks takes a day to spile and scarph, and a day each for the actual fitting, so twice as long as solid wood and nails. But not twice as long in time, as once you've glued everything up, which takes a couple of hours, you might as well go home and write... a blog post perhaps?

The Vendia/Collano marriage is still going strong and I cannot imagine using anything else now. No mixing, minimal mess and wastage, why bother with epoxy? As for Vendia, I think I said it all in my last post and for those who want the full paean of praise, read March Classic Boat in which I wax positively euphoric.


So that's the way it all looked on Saturday morning. Shape wise I am pretty happy. The garboard I made wide to give the planking a good start and support the centreline, the second strake is narrow, after which the strakes even out, until the hood ends after strake two should be about equal width.


Saturday, 20 December 2014

On the Third Day of Christmas (or was it fourth)...

... I had 35 boards of 6mm Vendia arrive, and what lovely stuff it is. Works nicely, planes beautifully, smells great (there are little pockets of resin occasionally which really bring out the sense of being in a Finnish forest), looks great and conforms to the moulds without needing to be steamed. I think I may have found the perfect compromise between solid timber and common marine plywood.


I have missed out, perhaps for the time being only, moulds 4, 5, 7 and 8 as there's not much happening that mould 6 can't handle. It makes it easier to work underneath. But if there's any hollowing or distortion liable to creep in I will add more moulds as seems fit. Either that or support the strakes using sticks from the shop floor.

As for Vendia as a material, when planing the lands on the garboards you could forget for a moment that this was a laminate; until you hit the middle layer, which is an excellent guide to the accuracy of the bevel.


Anyway, enough of this peaon of praise for Vendia, how about progress? Well, the garboards are on and spiling board strapped on to get the top edge of the next strake. So far so good. The skiff is designed for strip plank, so the moulds will have to be taken with a small pinch of salt. The smaller the better, but the other nice thing about Vendia is its flexibility. It takes compound curves to a degree without complaint, something to do with its relative softness compared to okume or hardwood marine plies.


Once the garboards were glued and the ends planed to the stems, I clear primed them to prevent them getting marked by grubby hands. glue or bird pooh (there's a little robin that occasionally takes refuge inside the shed).




Tuesday, 16 December 2014

The Vendia has arrived



The Vendia for the 16ft Gartside skiff arrived yesterday, crown cut, 35 planks, 6mm x 225mm x 3000mm at a cost of Eur 509.25. Add delivery costs from Finland to Ullapool, a not unreasonable Eur 219.00 and, with Finnish VAT (24%) the total was Euro 903.03, around £715, which compares quite well with a quote for a similar amount of solid larch at £650, or so delivered.






First impressions are excellent, both quality and working. The top two veneers on each side (of a total of five) are what they call crown-cut, close grained pine, with a nice figure and no end grain showing. Only the middle layer exposed. This should make it much more resistance to water ingress, and impenetrable once properly clear sealed.


The scarphs I cut to make up the garboards proved a joy, with no splintering under a very sharp plane. It was like working with solid pine, with a middle layer to give an accurate idea of the progress of the scarph itself. So, it is plywood, but not as we know it.

The only thing is I will need to be super careful gluing and handling it to keep the surface pristine as much of the boat will be varnished, perhaps all to start with, if I can persuade my owner...


To that end I intend to fine sand and clear prime the strakes as they are put up, to seal them while the boat is built.



Tuesday, 9 December 2014

Busy, Busy, Busy


Things are getting busy now with the Ilur awaiting final touches and the imminent arrival of 35 sheets of 6mm Vendia from Finland, ready to start planking the Gartside skiff, for which the stems have been made and beveled to accept the garboards.


The stems have been laminated from 20mm oak, cheeks of 6mm Robbins Eilte ply, with a further layer of 15mm oak each side just below the waterline to support the garboard at its twistiest. The ply template is to check the bevel is fair throughout the transition from keelson to stem.

Monday, 8 December 2014

Bob Begins: Two on the Go



While the Ilur is all but finished and awaits her rig, a Paul Gartside 16ft skiff is in ther making, with moulds lofted and erected on the strongback and a start made on the stems.
 

The planking is a bit of a departure: 6mm Vendia, which is a very superior pine-faced ply from Finland, but with grain and figure that looks natural as it is not roto cut from logs but milled through and through. It comes either crown cut or quarter sawn, both of which look like the real thing and thus can be varnished without looking odd. It's a halfway house between solid timber and plywood; a compromise, perhaps but will make for a light and strong boat. In larch the planking would need to be 8 or maybe 9mm as opposed to 6mm. And no rivets.


I have gone for 225mm wide, 3m planks, 35 of them which is probably over the top for just the eight strakes a side planned. The rest will be put to good use, perhaps as floorboards, thwarts, risers and possibly some traditional bent timbers.


The stem patterns give an early indication of shape. The stems themselves have been laminated thwart-wise rather than ripped and glued to shape round a jig. It may take a little longer but is more controllable, less wasteful and messy. The inner laminate will be solid oak, sandwiched between 9mm plywood with the end grain on the inside face capped with larch. A further laminate of oak will add strength to the forefoot, provide a wider face for the garboard and reinforce the scarph.


The boat is for an old friend and customer Jan KS, so I can expect a lively email conversation and lots of discussion, which is what I enjoy about building boats, especially when the owners are more knowledgable than I (which is mostly).