The last week was mainly a tale of 2 joints: scarphs and dovetails. We’ve been working on two types of scarph that could be used in a boat’s keel; the table scarph and the hooked scarph. These joints are used as they have longitudinal strength in compression and tension, which is essential for joints along the centreline of the boat. The table scarph is essentially a lipped scarph with a channel cut across it in which is fitted a small piece of wood of square section (called a table) which gives the joint it’s longitudinal strength. The table is craftily placed with the grain running across the joint, which has the advantage that if it gets wet, it expands along the channel, wedging itself even more firmly in. I found it harder to make the hooked scarph as it can’t be planed very easily in the rebated section above the hook, so it involved lots of chiselling, which is harder work and it looked less tidy when it was done; bearing the scars of a few near misses with the chisel.
I thought it would be plain sailing when it came to making dovetail joints as I’ve done a few before for various projects at home. Unfortunately, this previous experience doesn’t seem to have counted for much, I still spent hours on end fine tuning my tails so that they fitted together precisely enough. “I presume it goes in at a right angle” said Jon the tutor of one attempt; followed by “It’s quite a flexible joint”. I don’t think that was a compliment. Anyway, it’s all good preparation for the first big project, a mahogany tool chest. Hopefully I’ll be able to start on that in the next day or so. That will keep me busy for a few weeks.
An inexpertly chiselled hooked scarph
A more successfully planed table scarph
A lipped scarph (it doesn’t wobble, honest)
We’ve been making some proper boat joints this week. Plank scarphs which are what you would use to join planks together if the boat you want to build is longer than the planks of wood that you have, or if you want to replace a rotten section of a plank without replacing the whole thing. They consist of two tapered ends which have to fit together perfectly. That may seem obvious, but it’s easier said than done. ‘How flat is flat?’ is back to haunt me again. The tapers are cut roughly to shape and then planed within a nanometre of their lives. Then I try to match them together and there’s a tiny little wobble. But that just won’t do. The strength of a scarph joint lies in the fact that there’s a large surface area of contact between the two planks. A bit of a wobble means that there isn’t, so the joint will be weak and let in water. So more planing is required. Then I find that I’ve done too much planing and the planks are no longer flush, so I have to cut it off and start again. It’s fun; really. I’ve completed two scarphs so far; a lipped scarph which would be used for a boat with carvel planking and a feather edge scarph which would be used for clinker.
When you’ve mastered your tapering and become a scarph ace, you can’t put them just anywhere. Lloyd’s Register has rules about the use of scarphs in boat construction in order to preserve the integrity of the structure. If you look at the side of a wooden boat, any scarphs along a horizontal line must be at least 1.2m apart and in a vertical line must be separated by at least 3 planks, so you have to plan carefully where they go. They have to be the right way round as well, if the outside lip isn’t on the trailing edge of the joint, then water could be forced inside the joint and open it up.
I can’t claim to be a scarph ace yet, but I have got plenty of scars on the ends of my fingers and thumbs from the chisels. That’s my ailment of the week; at least I can stand up straight again though.
It’s keel scarphs in the next thrilling episode (probably).
A feather edge scarph
Ready for varnishing
In order to produce good quality woodwork, chisels and planes need to be sharpened several times a day, so an oilstone is an essential piece of kit. My mission for last week was to make a safe home for mine. This is a bit of a rite of passage for joinery apprentices. There must be loads of sheds and garages around the country which have an oilstone box made by fathers or grandfathers, stained with oil and years of service (the oilstone box that is, not the fathers and grandfathers).
So, starting with two lumps of sapele, I squared them up, hollowed them out, carved a fancy pyramidal shape on the lid and then applied several coats of varnish. Sounds easy, but it took four days. I’m three coats of varnish in now, so my box is nearly done. My oilstone can hardly wait.
Unfortunately, that wasn’t the only product of last week’ work. After spending hours on end chiselling out an oilstone shaped hole in a block of wood, I found that it was quite difficult to stand up again. I staggered to afternoon tea-break like Matthias in the Life of Brian. My legs are grey. My ears are gnarled. My eyes are old and bent.
New thing number three last week was a session with the in-house yoga teacher; which couldn’t have been more timely. The exercises were a godsend, and also got me thinking about posture and that sort of thing; after all, swapping the ability to be vertical on demand for the ability to build boats would be a sacrifice too far. A block of wood under each leg of my workbench seemed to do the trick. The bench is now high enough that I don’t need to bend over to work at it, and I can stand up again. Who said workstation assessments were a waste of time.
Time for another coat of varnish.
A week’s work
I’ve finished my bench hook and mallet at last. I’m not sure how much a mallet would cost down at B&Q, but I’m sure I couldn’t live on it at my current work rate. Although I know all the things that are wrong with it due to my beginner’s errors, it looks great now that it’s finished. It’s made of beech and as it’s a working tool it’s finished in boiled linseed oil, which soaks into the pores in the wood and hardens there rather than laying on the surface as varnish would, so it gives it some protection when it’s being bashed around; which I’m sure it will be.
Put these together to make a mallet
In ‘A Walk in the Woods’, Bill Bryson describes his adventures walking the Appalachian Trail. After slogging along the trail for a week or so, he sees a map of the entire route hung on the wall of an outdoors supplier’s shop. The map is several feet long. He looks closer to see how far he has walked and gets a shock when he realises that he has walked about an inch of it. He can see for the first time how far he really has to go.
I haven’t had to wade through waist deep snow or sleep in an open shelter in freezing conditions during my first week at IBTC, but I know how he felt. I now have my first inkling of what it will take to turn me into a boat builder.
Where do I start? My tools need to become like extensions of my body, my use of them confident. I need to understand the construction materials, how the grain lays, how to work with different kinds of wood. Accurate marking up and precise cutting with well honed tools. I need this all to become instinctive so that I can produce high quality work quickly. Then I can start learning to build boats. It’s quite a trek.
I won’t give away how Bill got on with the rest of the Appalachian Trail, but suffice to say that I hope I won’t be drawing on ‘A Walk in the Woods’ for many future posts.
We’ve started to settle into a routine in the joinery workshop. Our insular quests for perfection at our workbenches are punctuated by a morning break, 30 minutes for lunch and an afternoon break, during which we can relax and talk to each other; eventually. It takes a while to break out of our private worlds and start to engage with the real one. But then we start to talk and realise that we are asking ourselves the same questions. How flat is flat? was the question someone raised in one of the breaks today; and it was a question I’d certainly been asking myself. More flat than we realised, as it turns out.
We’ve started on two of our first real projects, which involve making some of the tools that we will go on to use for future projects. These are a bench hook (remember those from woodwork lessons?) and a beech mallet. The bench hook prompted the question in the title. A bench hook basically consists of 3 bits of wood, a flat piece and two short pieces of square section. To look at it, one would think that it could be knocked together in less than an hour. Not this one. We started with a rough plank of mahogany and have spent the last 2 days cutting it up, gluing it together and finessing it to a state of rectilinearity. We plane and plane until we think it’s as flat as flat can possibly be, then along comes Ian with his try square, holds it up to the light, and points out all the imperfections that we’ve missed. Our flat surface becomes a relief map, a landscape of hills and valleys that must be flattened. Back we go to the vice and plane away, creating even more varied landscapes in the process. In case we are in any doubt about what is required; when we look up, we are reminded by signs which glare down at us with instructive messages such as: ‘Perfection is the only standard worth aiming at’. Why does this remind me of Zen And The Art Of Motorcycle Maintenance?
My new desk
Well the first day went quickly. No messing around, a quick introduction and we were sharpening our blades, planing a true edge on some pine and mahogany and cutting a recess to join them together. I learned how to plane with the grain (I was never quite sure what I was looking for before), and the essentials of blade sharpening. If we can keep this pace going I’ll be building boats in no time. In fact it will be about 12 weeks time, all being well, that we’ll be able to graduate from the joinery workshop to the boat shed and have our first taste of real boat-building.