Thread: Nice rowboat, nothing fancy.

Hey , one for the Department of ####-ups.

So I'm at the stage where I want to start setting up the frames on the strongback. Naturally, since I was being lazy at the time and just built the strongback out of stuff recycled from an old shed, the top of it isn't exactly straight and level. It's a little bit whoopy here and there and follows the slope of the slab.

Following the slope of the slab isn't all bad, because the bow is at the low end so everything will sit quite nicely over the strongback. The difference in height is about 60mm end to end, and the difference in centreline height between stem and transom is about 85mm.

No problem, thought I. I'll just set stuff up straight and level on top of it, using Ye Olde Water Level (because I'd rather not spend the money on hiring a laser level for the day). So, I picked up 8 metres of 8mm ID plastic tube yesterday and started messing around with levels.

It doesn't work.

Turns out that in a tube that small, the surface tension against the walls is such that the level is inaccurate. I thought it'd be big enough, but it aint. It can easily be out by over a millimetre either way. That's too much for my liking. So, off to buy some bigger tubing. Meh.

I'll make the next one oversized.

ETA: Got 12mm ID tube. That works. Wouldn't go smaller than that in future.

K, set the frames up on the strongback.

I'm actually cheating a bit here. I just threw them up to within a few millimetres just for the fun of it, coz I wanted to see something boaty. I'll have to go over them and carefully check them all for positioning, before fixing them and bracing them. At the moment they're only really accurate for fore and aft positioning.

Looks fun though, which is what I wanted before pizza and beer. O0

Got the stem, frames and transom properly aligned and braced off. Still looks much the same as the last pix of course, apart from a few extra bits of bracing and stuff, so not worth posting more pix yet.

The next bit will be chine logs and the sternpost, closely followed by the bottom panel. That will be fun. That's when it will really start to feel like it's getting somewhere.

Anyway, re setup and all that: next time I think I'd spend more time on the strongback and get that really fair, square and level first. It'd end up being less aggrevating in the long run, because it'd make the actual setup process easier. Too many three-handed jobs involved in getting everything sorted, so anything to make it easier would be better. Still, I got there, even if it did drive me bonkers at times, and it was a good way to use up the old hardwood I had lying around.

I've triple checked everything all ways I can think of, including water level, string lines and an 8 foot aluminium straight edge, and it seems to be accurate to less than a millimetre everywhere. If it aint somewhere, I can't tell, so that's fine by me.

While I think of it, some general pondering about building another one.

Although the permanent stringers and frames idea is a good way to minimise leftovers (no full jig going to waste afterwards) I wouldn't use it if I had to build two or more of the same boat. In fact, to be perfectly honest, I'm not sure I'd do it again even for one boat. I've done it before, and it works, but these days I'm finding I'm less patient. I just want the damned thing in the water. Also, when I did it before it was a simpler hull shape with fewer planks. That meant fewer stringers, therefore less work.

So, on reconsidering I think it'd be better to build up a jig with fairly solid stringers and just plank over that. There would be less finish work involved, even with having to put in the permanent frames later. Materials cost would be a bit higher, but not a hell of a lot, and even if only building one boat I'm sure the wood from the jig could find a use elsewhere.

The Finnish builder who does the Savo/Sulkava race boats builds his that way, and it'd certainly be the easiest for building several of one type. The stringers mean fair laps are a piece of cake, and cut production time once the jig is built. Even if just splitting the cost of the jig between two boats for a couple of mates, I think it'd probably still be worth it.

I've cut the scarf joints on the chine logs and stringers, and got them glued and clamped up. Not a big whoop, but the chine logs should go on the frames tomorrow evening, which will be nice. I'll be able to bend them on after a full day's cure, since there wont be much stress on them. It's at the stage where things should start looking more boaty fairly quickly.

Anyway, just for the hell of it I cut the scarfs a different way this time. Usually I'd just do them with a block plane, but I'm on a bit of a router thing at the moment, and the bits I'm using are quite fiddly, so I knocked up a little jig out of scrap cedar and mdf just to see how it went. Pix attached. Router just sits on the mdf and runs along the cedar guide, of course. The direction of the cut is set so the router bit is pushing away from the cut. Pretty quick and easy. Resulting scarf joint shown, just sitting side by side without glue or clamping.

Since this was just a test of the idea, I was just pinning it down with panel pins into a scrap plywood base, which explains all the holes. I found that one pin near the feather end of the scarf kept things nicely in place while routing, and the resulting cuts were good enough to use. I could get them a little better at the feather ends by getting fussy with a sharp block plane. but I aint feeling that fussy. They're fine as is. In case you can't tell, I'm getting lazier as I get older. Or is that smarter? One or the other, or both.

Chine logs are on. They're notched about an inch into the bottom of the stem and sternpost. Will give them a bit of a clean up and rough out the bevels tomorrow. After that, it's scarfing up the bottom panel. By Sunday night, the bottom should be on.

I've added some temporary props between the frames, just because the chine logs needed a bit of extra support at this stage. They're stuck to the props (and the two temporary frames) with blobs of hot melt glue, which is easy to get rid of later. That'll hold things nicely while I work on it some more, without creating dramas down the track.

Just precoated inside face of the bottom panel. Meh. Effin epoxy. This stuff is not fun.

Since I only get it into my head to build a boat every so often, it's been years since I coated any surfaces with teh pox. Area of the bottom panel is around 1.3 square metres, and I have nothing else I want to precoat at this stage. So I made a half litre mix and slathered it on, then rolled it every which way to even it out. So far, so good.

I'd brushed the plywood clean before starting, but despite that all sorts of magical fibres appeared out of nowhere and promptly decided to point at the ceiling. Awesomesauce.

Also, Bote Cote claims their epoxy contains a nifty bug repellent. This may well be true, but unfortunately the bugs at my place do not seem to have read the instructions. If anyone knows how to get bugs to read brochures, that would be really cool.

Anyway, pox is on ply. That roller soaked up an awful lot of the half litre mix, but there's still plenty on the ply. That's all it's getting too, at least for now. I bought a 3 litre kit for the external glassing and internal coating, and that's what I'm using.

Yes, I know, I know. If I don't buy 579 kilos of epoxy and a container of rollers and a spacesuit and some special rosary beads, God will murder kittens and my testicles will fall off.

Don't care.

I like building boats out of wood. The inside of the bottom and the garboard are getting one thick coat of pox to sorta balance the 200 gsm glass cloth on the outside. The inside of the bottom and the garboard will be painted. The rest of the boat is getting paint (outside) and oil (inside). No more pox outside everywhere. Just paint. No varnish inside. Oil. I like it.

Yes, I know. Kittens and testicles. Whatever. This is an open boat which will be stored under cover, out of the weather, with good ventilation. I'm finishing it the way I want to. Not that I would necessarily recommned everyone else follow suit, but I have a good idea what the trade-offs are and I'm happy. YMMV.

Bottom is on the boat. I would have had it on yesterday, but I ended up spending several hours making up some simple U-and-wedge planking clamps. It's a good thing I did too.

As you can see from the pix, I really could have done with a few more down aft. It'll be fine though. I've checked for contact everywhere, and there's no rocker aft, so it all just sits together quite well.

Working with scantlings this light is quite relaxing in one way, since everything is light and easy to bend, but it also requires some care in clamping and general checking for fairness. It's a bit of a trade-off in terms of convenience.

Anyway, lotsa clamps is good, especially if they don't weigh much. I made 30 yesterday and will be making some more today. This is what I wanted the big box full of wedges for. Remember the box of wedges? I like wedges. Very handy things.

Dimensions of the U-shaped bits 240mm long and 100mm wide, with a 180 x 30 throat (I have no planks wider than 150). Ply thickness is 12mm, from what was left of an old sheet of CD radiata I had lying around. This is stiff enough to work well for the sorts of pressures I need, but may need beefing up for working with heavier scantlings. The wedges I use are 5 degrees, which is near enough to 1:12.

The last pic is a large framing square I made for setting up the frames on the strongback. It looks rough but is actually very accurate. It's based on a 5:12:13 triangle, which is a handy one that some people don't know about.

3:4:5 is the most well-known right-angled triangle, but for this purpose 5:12:13 gave me a more accurate result without being unwieldy. The two triangles have a 3mm gap between them, which allowed for the stringline down the centre of the boat to clear the plywood.

I don't need it any more, and I do want more planking clamps, so no prizes for guessing what I'm going to do with it. I can easily make another one for the next project anyway.


PS: Oh and the epoxy on the bottom turned out fine, after a bit of sanding. I did lay on quite a heavy flowcoat of it, so there seems to be plenty left. Nonetheless, in terms of time and materials it wasn't an efficient way of doing it. In future I would try to avoid using a roller for areas less than about 3 square metres (just soaks up too much for small mixes) and would be inclined to try some of those tricks with plastic sheeting over the pox. Will have a think about it before I precoat the inside of the garboards.

The old framing square had enough ply in it for another 20 planking clamps. Those are rough cut now and just need bullnosing and sanding to clean up the edges. Since it's so easy on the router table, I've been running a 3mm radius bullnose around the clamp edges. It's not only nicer in the hand and less likely to splinter, but makes the wedges slide in easier.

And just for fun, because I like looking at it at the moment, pix of the bottom on without all the clamps in the way, and a shot of the inside of the boat turned right side up.

Here ya go. First stringer in place.

It still needs to be trimmed for length and notched into the stem and sternpost, but the starboard side of the stem is bevelled up to above the first lap and you can see the line of the garboard now. If you look at the line of the stringer carefully, you may notice it's not quite on a fair curve from the stem back to the next two frames. This is because it's still sitting 8mm outside its finished position at the stem. It'll come good once it's notched in.

This bit is fun. I love carving out the shape of the stem.

So I had one of those "First pants, then shoes" moments.

After getting that stringer notched into the frames, a thought occurred to me. This happens at times, and usually means trouble.

The thought was that really I'd be better off if I did the rough bevelling for the chine/bottom before gluing the first stringers into place, just because it'd be a bit easier to do that without the stringers getting in the way.

So, I popped the stringer out again and sorted that bevelling to about 1mm outside the final line. I'll take it down to the line once both stringers are glued into place, so I can use them as a handy guide for the final cuts.

I've also bevelled the port side of stem and sternpost now, up to above the first stringer. They also need a little bit of final fairing, so that'll be the next job. Get those faired properly, then notch the stringers in and glue them. Then I can finish off the chine bevels.

That'll work.

Another one for the Department of Stuff I Should Have Thought of Earlier.

Them stringers. I put a nifty little 3mm radius on their inner edges, which is nice and neat and well-proportioned for the stringer dimensions. The only problem is notching them through the permanent frames at weird angles. That is, quite frankly, a damned nuisance if you want to make a good job of it. Come to think of it, notching them into the stem and sternpost is also a nuisance.

What I should have done is the same thing I did with the chine logs: mark where they cross the frames and rout up to those points, leaving the section rectangular where it crosses the frames. That would have made clean and accurate notching very easy.

I did actually consider this, but decided against it because I thought it would look neater if I just ran the same bullnose all the way along. It would look neater too, in theory. It would even look neater if someone did a perfect job of it in practice. Unfortunately, I aint that someone, and the cuts are a little rough in places. However, the boat will still be well-proportioned and structurally sound, even if not quite so flattering to my ego, and it'll still look totally awesome at sunset from ten feet away.

So at this point the intelligent reader may be wondering why the silly bugger did this clever trick on the chine logs but not on the stringers. The answer is that with the limber holes being a continuation of the notch for the chine log, running the bullnose under the frame there would have looked horrible. So, I made it look not horrible. That bit works. I just should have carried it through to the stringers.

Brainwave!

I made up some mini "files" for doing the rounded corners of the notches in the frames. Should have thought of that before, too. They're just rolled up 80 grit sandpaper, held together with a thin line of glue at the outside edge. With the cedar being so soft, they work very well.

I could have used a real round file, but that would have required buying one small enough. A nice gouge of the correct radius would also work, but it's another thing I don't have. I can make these for free out of worn bits of paper, and the small size and negligible weight makes them very convenient to use.

By the way, the notching into the stem and sternpost is just a straight 3:1 bevel. Pic attached. Stem isn't completely faired yet, just pretty close.

Garboard stringers are now permanently glued on the boat! This calls for beer!

I even managed to get the whole process completed without swearing. Forward planning FTW.

There's packing tape all over the place to stop glue getting where I don't want it. Packing tape is good on the cedar. Comes off easily without tearing the grain up, and epoxy wont stick to it.

The clamps have a 3mm MDF packing strip between them and the permanent frames to stop the cedar crushing, and taped in place so I didn't need fifteen hands to get the clamps on.

The pine temporary frames just have holding strips screwed on over the stringers, just to keep things in place while I sorted everything else, then got a bit of hot melt glue on them.

The stem and sternpost needed a bit of persuasion to get the twist in the stringers, so they have the screwed holding strips backed up by some nifty stringer-twisting clamps I whipped up. These have heavy rubber bands pulling the pair of them together to help hold the twist. They're a sliding fit over the stringers, and are grooved for the stringer rebate, meaning they stay where I put them and don't fall off.

All up, it worked perfectly. I was amazed. At least I now have the process sorted, so the next stringers should be easy.

Tomorrow I'll ditch the clamps, and the holding strips from the temporary frames, and get into the final fairing of the bottom/chine logs. That means next week I should be spiling garboards.