Thread: Nice rowboat, nothing fancy.

Starboard gunwale is on. I ended up putting 10 gauge stainless screws at approximately half metre centres, partly because I thought it should have something extra at the ends and the permanent frames anyway, and partly because trying to line up long, bevelled bits of wood that want to slide around on epoxy is a PITA. Having the screws already drilled after a dry run made alignment a lot easier when it came time for gluing. The screw holes are bunged, of course, so it'll still look clean.

Port one is going on tomorrow. After that, just a bit of clean up, then turn the bloody thing over.

Bloody thing is turned over! About time. Looks better right side up.

It's light. Don't know how light yet, but I can easily carry it on edge with one hand taking all the weight, and the other hand just being used to steady it laterally. It's also close the limit for stiffness. Adequate for the intended use, but wouldn't really be up to carrying three people onto a beach through surf. It'll never have to do that anyway, and would be fine solo as long as the surf wasn't over the top.

I am currently thinking about laminating a thin strip of hardwood around the outside of the cedar gunwales. If done carefully, this could increase the stiffness of the sheer substantially for minimum weight penalty. I've only just taken the thing off the strongback, so haven't thought it all through in great detail yet, but offhand a strip tapering from around 6mm thick amidships to 4 at the ends sounds about right, if I go ahead and do it. That'd cost somewhere under 1 kg in weight. Since I'm thinking about it, that's probably a sign that I should do it. It'd have the additional advantage of making the gunwales a bit more bash-proof.

Anyway, pictures.

ETA: Got it weighed. As shown in the pics, with two temporary frames and some crossbraces still in place, it is 27.4 kg, which is a smidgeon over 60 lbs. The stuff that has to go into it (quarter knees, breasthook, one thwart in race trim, footbrace, rowlocks, paint) will probably weigh about the same as the stuff that has to come out, so that means in race trim it should be around the current weight. There will also be an additional forward thwart and a passenger seat aft, but they'll be removable for racing.

Cleaned it up a bit, and have been pondering how to do the breasthook and quarter knees. Mocked it up with a bit of scrap and have figured out how to tackle it.

I'm starting with the quarter knees. Usually they'd be separate items, but after looking at it and thinking about it I've decided to make a continuous laminated bend that does both in one. It just seems to fit nicely and look good. I should be able to laminate this in situ, which will save making a form for it. Having it carried a fair way forward on the sheer clamps will effectively shorten their span between the frame and transom. Since deflection is proportional to the cube of the span, this should stiffen the aft sections up nicely.

It'll also go with the way I intend to do the passenger seat, which is going to have a curved backrest/armrest combination like the traditional Chinese lohan chairs. These are good-looking and very comfortable to sit in, and a simplified version will be easy enough to make. I'm well into laminating stuff for this beast, so may as well keep going.

After I have the stern sorted I'll eyeball it a bit and see what would match well at the bow. I've decided how far back I'll be taking the breasthook, but haven't yet decided whether I'll have an open section between it and the stem, or whether I'll turn it into a very small foredeck. Which way I go there will determine how it is put together. If using an open style, obviously the bend will be laminated. If using a closed style, I'll make up a sandwich with cedar facing, and a plywood core for cross grain strength.

I'm also going to do that extra hardwood strip around the outside of the gunwales. Have pigged around in the timber stash and found a couple of lengths of dressed 2x1 in New Guinea rosewood. This stuff is moderately dense (roughly the same as most things that called ash), is easy to glue, very stable in the weather, and looks quite decent. So, it seems like the logical choice for the extra strip.

I'll split it down into strips 6 or 7 mm thick. A rough calculation on basic beam theory says that the additional strip should add at least 50% to the stiffness of the gunwale/sheer clamp combination, which seems well worth it for the extra kilogram involved. Given how light the thing is anyway, I think I can spare an extra kilogram on the prototype.

Got the strips milled for all the laminated bits to come, but spent yesterday doing some cleaning up of cured epoxy squeeze out. I couldn't get to all of it while the boat was on the strongback, so am having to do some now. I was not looking forward to this, but have come up with a method that makes it fairly quick and painless.

The approved method is to wave a heat gun around until the epoxy starts cooking, and then scrape away. I was concerned about using this method due to the lightness of the construction on this boat. Heat doesn't just soften epoxy. It also softens wood (which is how steam bending works). The planking on this boat is 3mm ply, which means the face veneer is only 1mm. No margin for error. Also, the amount of heatgunning required to soften the epoxy could result in heat transfer into the glued laps, etc since the thermal mass of the (small) structural elements is quite low. This would not be good.

Brainwave: since I'm only wanting to remove fairly small blobs and beads along lap lines, etc I only need to heat small volumes of pox. So, how about using a soldering iron? This would produce heat right where I want it, with pinpoint accuracy, and should mean effectively zero heat going where I don't want it.

As a first test of the concept I used a hot melt glue gun, which I already had. Pulled the glue stick out, heated the gun up to operating temperature, wiped all the old melted crap off the end of the gun so it was just clean metal. Then, got a 2" (50 mm) stainless steel paint putty knife ready and applied the tip of the gun to a bead of cured squeeze out. It works. I just held the tip of the gun on the bead for a few seconds and the epoxy in that small area softens enough to let go of the timber with no damage and no apparent residue. The timber right next to it is still stone cold. However, the tip is too bulky for some areas and it doesn't generate enough heat to deal with bigger blobs quickly.

So, I bought a basic 80 watt soldering iron and gave that a run, in combination with the putty knife. This is very good if use with care. If not used with care, the tip of the soldering iron will burn the timber. There is an optimum temperature where the epoxy softens just enough to let go of the timber cleanly, but without breaking down the epoxy too much. This is what you want to aim at because it gives the cleanest results. At its best, the result is as good as if there had never been any squeeze out at all. It looks perfect.

The best technique I found was to use the tip of the soldering iron on top of the putty knife blade, close to the leading edge and just outside the bead of rock hard poop. This enabled me to slide the knife along the poop slowly, with light to firm pressure and without forcing it, and peel it off nicely. The area of the putty knife blade dissipates the heat from the soldering iron to the point where the blade wont burn the timber, but is still hot enough to deal with small beads of poop quickly. Bigger blobs take a bit more time, and sometimes it helps to touch the iron directly to the bigger blobs to cook them up fast.

Anyway, after all that I have had another brainwave. What I am going to try is getting a scrap of knife blade and welding that to one of the tips that came with the soldering iron. The cunning plan here is to take a two-handed job and turn it into a one-handed job. It might even work. If it doesn't, I can still use the two-handed method.

I use a propane torch on a multi tool blade and work carefully.

Sounds good. If I had a multi tool and a propane torch I might try it too. I agree that with any of these tricks "work carefully" is going to be the important bit.

So today I'm playing with thwarts and rowlock blocks. This may seem a daft thing to do at this stage of the project, but it's fun and they have to be made sometime.

The thwarts are being done Norwegian style - notched around the frames, without being permanently fixed into the boat, with ends tapered for width. They just drop into place. The boat is strong enough without using them for bracing and I just like the convenience of being able to remove them.

Anyway, while making up patterns for them I had a thought, which was that I could taper them for thickness towards the ends too, instead of just for width. This makes sense for the engineering side of it, if anyone gives a rat's, but the cool thing about it is that it'll look nicer.

I mocked it up with the pattern, and having a slight spring across the thwart does give it a nicer look. It's not something you would easily pick if you don't know it's there, but it just looks better without being obvious why. The taper in question will be only 5 or 6 mm over about 450 of thwart each side (about 900 total width).

So, next step after that will be to cut a matching shallow curve to the lower edge. The cross section of the thwart will finish rectangular at the ends, and six-sided in the middle - flat top, two vertical sides, a flat underneath about 60 mm wide, and tapering from that up to the vertical sides about 6mm higher. This is not hard to do, and is nice work, and will give the result I want.

At this point you may be wondering why this clown included "nothing fancy" in the thread title. Ok, so don't believe everything you read on the web. It's having a few nice touches here and there. They just seem to fit and I feel like doing them.

Then there are the rowlock blocks. I've decided against hanging these out past the gunwales. My reasoning here is extremely logical. I'm just enjoying the sweep of the sheer so much that I don't feel like interrupting it with blocks hanging out the side. The gunwales are chunky enough to take a hole drilled on the neutral axis without any dramas, so I'm sitting the blocks on top of the gunwales. This will cut the spread slightly, but I've been thinking about how much spread I really need and think it will still be more than adequate. It'll come in at 1200 mm (47"). This is still a lot more than any guideboat, and those things go fast for miles on end anyway.

As soon as I made this decision I went looking for a suitable chunk of wood for the blocks. Something that wouldn't waste a good length and was around 50 x 25. Found a piece of NG rosewood sitting in the corner. It had two fractures across the grain, which made it useless as a single length, and the fractures were just far enough apart to get a block between them, and between the last fracture and the end, with enough left over at the other end for the other two blocks. Perfect. I took this as an omen from my favourite non-existent deity of the day, whoever that happens to be, and am proceeding forthwith.

The blocks are currently glued to some scrap cedar strips, just so I can bevel off the ends of all of them in one hit. Easier than frigging around with small chunks of wood.

More mess coming after lunch.

So, now have rowlock blocks roughed out and the centre thwart just about finished. The latter still needs a bit of a sand and a small bullnose on the upper edges, but is basically sorted. Tapering the thickness with a hand plane was easy and pleasant, and the result looks great. I gave the top just a little less vertical curvature than the lower edge, so the thwart appears to thicken very slightly towards the end. This looks better than having the edge a constant width.

I think I figured out what is going on here. With the thwart being tapered for width, when you are looking at it from normal angles the curvature of the edge often makes it appear slightly droopy. Giving it a slight spring upwards counteracts this. It's not in your face, but subtle. If you haven't seen the tapered one compared to a flat one you might be wondering what all the fuss is about, but trust me it makes a hell of a difference in 3d. The whole thing just feels more "alive", for want of a better term at the moment.

Rowlock blocks are just sitting on top of the gunwales at the moment, so I could eyeball them for basic proportions. I'll tart them up a bit more once I get the sheer clamp planed down to match the gunwales, which will be after I glue on those extra rosewood strips around the gunwales, which will be after I scarf the things for length. The scarfing will happen tomorrow.

Got a few more bits done. For'd thwart is now sorted to the same stage as the other one. After looking at them both in the boat I figured something out. I'm not going to re-do them this time, but with the for'd one being shorter it gives the appearance of being wider even though both are the same width. It's not a big deal, which is why I'm not going to worry about it now, but if I was doing another boat I'd make the centre thwart about 5 mm wider than the for'd one. This would make them appear to be equal in width when the effect of the different lengths was taken into account.

Thwarts.jpg

Also got the strips for the quarter knees steamed up. I bent them freehand into the boat to start with, but wasn't happy with the resultant curve. It was too parabolic, with the curvature concentrated towards the middle of the transom. I wanted a fuller and more even curve, so decided to bite the bullet and just make a jig for thing after all. I was able to use the same strips as they took the new curve just fine. At the moment they're just drying out and acclimatising for a couple of days before I glue them up.

Quarter_knees.jpg

Then there's the footrest. I wanted something decent to brace against. None of this silly business with little strips against the planking or whatever. I like something that goes from heel to the ball of the foot, with the feet at a natural angle to each other. Toes can hang around in mid air, but the rest is better with a solid platform.

A solid plank wouldn't be stable enough and might split. I didn't want vertical supports added behind it either. I wanted a self-supporting panel, to allow for an additional position that catered to taller people with longer legs than me, in case one of them uses the boat sometimes. Catering for shorties is easy (just have more notches further back, which bring the footrest further forward, if that makes sense) but with the position of the permanent frame compared to my leg length an extra position for taller people means the footrest panel being shoved up against the frame.

So, this meant making something up. I could have used ordinary plywood, but that would look like crap unless I put edging strips on it, which is more hassle and often doesn't look that great anyway. Cedar is really a bit on the soft side for this job, since dirty boots will end up going against it sometimes, but I wanted something that fairly closely matched the cedar framing in colour since visualising the finished thing made it clear that's what would look best. Having it match the planking wouldn't look as good, so pine was out. This means New Guinea rosewood to the rescue again. It's hard enough, the right colour, and has excellent stability.

I happened to have some 70 mm x 7mm strips that were dressed on one side and sawn finish on the other, so I dressed a couple down to a bit over 5 mm. Wasn't too fussy about the thickness, just wanted both sides cleaned up. Docked them down so I had six pieces in total. Three of these were then edge glued to make the forward side of the footrest panel, with the other three being made into the aft side. To get the cross grain strength I wanted, these panels were then routed out on the inner faces to take some offcuts of planking stock, with the face grain running vertically. The pieces of planking stock are just butt joined, but the joins are offset in each panel. The result is a custom 10 mm thick balanced plywood panel, that has 2 mm thick rosewood faces each side to handle a bit of wear and damage, with built-in edgings that give the whole thing the appearance of a solid plank.

This may seem like a lot of messing around for a flat thing to stick your feet against, but it wasn't difficult and to me it was just the easiest way of getting the result I wanted.

Been playing around with that footrest a bit more. It's not glued up yet but is basically sorted. Pix attached. Upper crosspiece and back legs are mortised and tenoned into the side rails. Crosspieces underneath will be screwed and glued up to the side rails. The big flat thing for the feet will be screwed and glued to the rest, with the screw heads bunged for looks.

There are four positions available, spaced 50 mm apart. This equates to ideal positioning for heights of 1.5 m, 1.6 m, 1.7m and 1.8 m. I'm 1.7 so this is fine. If anyone is 1.9 m, which is fairly rare in Australia, they can ditch the footrest and just put their heels directly against the frame itself. Not quite as comfortable, but good enough.

Got some more done. The footrest is all glued and cleaned up now. Looks much the same of course, so not really worth more pictures. Got the rosewood strips for the gunwales scarfed and have just put the port one on the boat. Naturally this involved me finding out that I didn't have quite enough clamps handy, madly scrounging everything I could, and just managing to scrape in. Anyone who has built a boat will recognise this as perfectly normal operating procedure.

I'll throw the starboard one on tomorrow, when clamps are available again. Also got the quarter knees glued up. I'll leave those on the form for another 24 hours just to make sure things are well and truly set, then they can go in the boat too. After that, the only things required will be the breasthook or foredeck, however I decide to do it, and then the rowlock blocks. Once those are on, all the structural stuff will be done and dusted.

Then I can think about oars. Oars are fun to make, so I'm looking forward to that. I'm thinking I might also make up a push pole (or quant if you want to be all Olde English about it) since those are a handy thing to have in shallow water or semi-liquid mud. It's a nice way to move the boat if space is tight and the water is shallow enough. Since they're so easy to make, might as well have one.

Starboard one is on. Turned the boat around for this one, since having the starboard side next to the workbench made more sense than trying to get a long and sticky strip of wood over the top of the boat to the other side. I must say it really is nice having the boat built so light. It makes moving it around a piece of cake.

I've decided I need to make some more of those gunwale clamps. I'm thinking about another dozen should do the trick for now, and they will be useful for things apart from gunwales. For one thing, they're a good size for oar blanks.

Also decided that I am going to take that for'd thwart down in width slightly. This morning I realised that I've spent more time thinking about it than would take to do the job, which is getting a bit silly. Might as well do it, then all the time that in future would have been spent thinking about it can be spent feeling clever. This has to be a superior option.

Popped the quarter knees out of the bending form today. Very little springback, about 5 mm each side. Fits well. Just needs some shaping to make it look a bit slicker. I'll give the ends a nice taper and all that. Fun with hand tools.

Quarter knees permanently are in the boat now. They have made a quite remarkable difference to the stiffness of the boat. Without them, grabbing the corner of the transom and moving it up and down caused noticeable flex in the aft sections. Ditto grabbing the stem and shaking that side to side. I could see the transom wobbling more or less independently of the rest of the boat. Now it's a lot stiffer. I can do the same thing and the whole boat just moves as one unit from bow to stern. This is good. Happy I am being.

So that leaves the breasthook as the last really structural piece still to go. The parts for that are made up, and will be glued together after lunch. It's being done the same way as the footrest: two layers of 6 mm rosewood laminated together, with rebated inner faces to take another two layers of 3mm plywood with the face grain running across the boat. Light, strong, and good-looking.

The tops of the sheer clamps will be rebated to take the breasthook, which will be cut to fit directly against the inner faces of the gunwales. As well as giving a slick finish, this will provide plenty of gluing area for strength. No fastenings will be used.

The long, shallow wedge in the second picture is going to be used to force a slight camber into the breasthook when I laminate it together. The edges will simply be clamped down to the bench top, giving a nice curve for looks.