Thread: The Little Black Dog - MSD Rowing Skiff - Adelaide OZ

Hi Richard,
I just caught up with this topic, I can see so easy how the glueing went wrong , oh sh one t. I am also coming to feel that this would be an easier build stitch and glue over frames.
Before you plane the old bed away, why not just plane it back to just 6 or 8 mm, this will be bendable when you put it together and still allow the pretty open inwhale to be built.
You asked a couple of days ago how/why I did the dry fit the way I did..
I fitted it upside down because I would be screwing from above (my usual preference)
I started with frame 3 because it has no bevel and the side arms are already attached, giving 2 clamp positions. 2 clamps firm but not tight allows small adjustments with the tapometer before tightening and screwing.
I held the side on the stools and the other side of the frame touching the floor. I then put the screws in.
Then I undid it and repeat for the other side except I didnt undo it, I put the first side back on which made the whole thing sit up as a floppy H on the stools.
I was then able to do frame 4, I discovered that after I attached it to the first side it was easiest for lining things up to back the screws odd a turn to allow a sloppy fit, thenattach the second side, then tighten the first side.
This does pull the bow sections apart a bit, but not rediculous.
I cant remember if I did frame 2 next or the transom ( Ive had a couple of sleeps since then) but I did have to use the ratchet strap to pull in the transom.
Frame 1 was the fun bit, partly because I had the gunwhales screwed on. I got it done with ratchet ties and if you cant get helpers you will certainly need to give yourself some way of controlled tightening, trucky knots or spanish windlass if you dont have ratchet straps and remember that ropes and straps wont want to silp aroumd the sharp corneres you are tightening around. And loosen the screws before you do the other side. My bevels are not perfect and my chinelogg gaps arent either so there will be a bit of bogging to do
After frame 1 was in place the bow wasnt too bad, just hip and heave and put the clamp on and screw it up
The only reason I did it that way was so I could work above the job in the first place and I thought that starting in the middle would be most stable.

I think that for glueing I will do it in a similar order, but right way up so I can look down as I glue, the holes are drilledand that will make the cleanup easier.
I think.
The other thing is to use long screws into the frame tops and bottoms to pull them in close for glueing because the screws will be providing tension while the glue sets and there is a bit of curve in some of the frames.
Another thing by doing it upside down is is that you can see if the center line of the frames are trueand lined up to the bow and plumb. More or less.
I hope this helps
Tom

Thanks for that Tom.

You're dead right about leaving the screws a bit loose while fitting things together. I'll be leaving everything a little loose and then tightening things to get the final shape ... well, that's the plan.

I'm also hoping to be able to fit it together, then remove each bit for gluing, but that's just theory and blind hope at the moment - the twist in the sides, the flare and the tensions may make that impractical or not as simple as pulling it all apart and starting from scratch.

Tom, did you have the triangular stem piece fitted? If so, which one, the original or the later one? How did it fit?

You also commented about your bevels. Mik's said elsewhere that the bevels are a bit of an average and that he expects gaps - this is why we use epoxy, it fills gaps. This also allows us to shuffle the whole lot around to make sure it's square and straight.

I've swung back to leaving the dud chine logs glued to the sides and using them as the inwale. I may attempt to cut bits out and use it the spaces but probably won't bother. Although I prefer the look of the spaced inwales, and they do make it easier to get all the water out, and they do give you somewhere to tie things to, I'm not sure any of those reasons are going to be major considerations on this boat. Removing the existing timbers provides plenty of opportunity for stuffing things up as you get near to the plywood, although I wouldn't hesitate if I had to. A balanced decision seems to be to go with what I've got and to just make it work, a decision helped by looking at the photos of the skiff at Duck Flats, which had the solid inwale and didn't look too bad.

As for the extra timbers - the gunwales I cut the other day will become chine logs and the inwale timbers (they're only 12mm) can be laminated to make gunwales so all I've really lost is a bit of glue and effort.

The big question is 'glue it upright or glue it upside down'?
The flare of the sides makes upright and on the ground difficult, something that's made considerable worse by my cramped building conditions - someone with more space may have a different experience. However, lifting her onto a couple of saw horses gives me more room. Upright makes it easier to see what you're doing but makes it harder to get at the screws. Upside down means you have to work underneath for cleanup and lining up so probably upright on saw horses will be the way to go ... maybe - this is why you dry fit, to find out these things.

As for my comments earlier about building over frames - I should make it clear that most of that is personal preference. I've always preferred to jig things and don't mind spending the time making the jigs. For me, the effort in building a jig is paid for in the ease and accuracy in which things go together - Hawk will attest to that from my aeromodelling days. For others though, the frames are just something else to make and don't mind all the flopping around that goes on with jigless building.

Tomorrow? Gluing on chine logs ... now where have I done that before?

Richard

Howdy Richard,

I have noticed that people who have had experience of plank on strongback building have difficulty making the transition to this type of boat building.

I really don't know if it is my myopia that makes it seem not too difficult. Usually once the dry run is done the method gets clearer Though it might be a bit tricky with the "inwales in place. I might need to give you some frame heights and then you will need a dry run to make sure the side panels don't become concave or convex because of the chine log being in place.

Generally I do suggest starting at the stem because as this is the most highly bent part, the hightest loads are ther and the lightest loads are in bending the back together.

It is a method that does take a "leap of faith" that it will work - just go through and assemble step by step as the plans say. It is wobbly like spagettini, but ignore that and go through the process.

The thing that gives the sides and bulkheads stage some reliable form is to get the bow apex together too - as that triangle will stop things from moving around as much. Otherwise it is a most rickety ladderwork.

MIK

Originally Posted by Boatmik

Howdy Richard,

I have noticed that people who have had experience of plank on strongback building have difficulty making the transition to this type of boat building.

I really don't know if it is my myopia that makes it seem not too difficult.

Both the Mouseboats were stitch and glue, without frames so I'm familiar with the system and the way it stiffens up. Interestingly, Redback was partly stitch and glue on frames (plus screwed plank, plus 'jam the bloody thing in place and hope the poxy holds').

I don't have a lack of faith in the system, just prefer a framed approach - a bit like choosing what brand of car you want to drive.

As for starting at the bow - no problems there because it was surprisingly easy to do this outside and then carry the floppy mess (just joined at the bow), into the shed. Incidentally, with both sides screwed to the stem piece, the back end of the sides were 3.2m apart (yes, I measured it and that's why I couldn't do it in the shed) ... but I was able to draw the ends in together for carrying.

Wont it be fun trying to bend this thing to shape with both the chinelogs AND my inwales (the old chine logs) glued in place

Anyways, that's for tomorrow, I need to glue new chine logs on today.

Richard

Cool.

Hokay, it's been a few days. I've been out doing stuff but spasmodically and some of it less well than other bits but I've been slowly achieving stuff.

You may recall earlier, when notching the bulkheads, I commented that I'd made a bit of a cock of the whole deal. In positioning the chinelogs, I took each bulkhead and worked out exactly where the chine log had to sit to fill the notch and have the bottom of the bulkhead match the bottom of the side - I simply held the bulkhead in place and dropped a steel ruler along the bottom to see where the bottom landed, got the ruler to hit the bottom of the side and put in a pencil mark. As expected, in most cases, the chine log had to sit a few mm higher than designed - the chine logs were then clamped to these marks (there are only 4 bulkheads so a fair line wasn't a problem). A bit of mucking about bit it means I'll have better joints and there shouldn't be any need to plane the bottom of the bulkheads to get them sit flush across the bottom of the boat.

Here's the final result - new chine logs glued on and the edges rounded off. They look bigger than they need to be because they used to be gunwale stock which is wider. I'll have to plane the excess off but at least I'm unlikely to find I don't have enough timber there to fit the bottom.

Look at them lovely sticks glued to them sides - won't it be fun bending that lot around the bulkheads come assembly time (Mik specifies that you assemble the boat with only the chine log glued in place, then clamp on the gunwale to give it some shape).

Richard

I got keen and did a dry fit
Man it's fun bending this brute into shape, especially as its got it's own ideas about what shape it wants to be.

Right. First piccy - joined at the nose.
I didn't use the triangular stem piece because I'm concerned about what the actual dimensions at the front will wind up being and am concerned that the stem piece I've made is too wide ... at least at the bottom.

Attachment 117200

Second piccy - heavy restraint.
I could have just wired the front together, but didn't have any suitable wires so I used four bolts ... and because I didn't have bolts long enough, three of them have washers under their heads, not plywood pads

Attachment 117201

Third piccy - flamin' heck Storer, is this supposed to bend?
Half way done ... sort of. This boat really does like to go together from the front backwards, and you do have to do them in order because angles and stresses change from bulkhead to bulkhead. The strap at the back isn't really needed at this stage but the spreaders make a big difference. Part of the secret is to remember that the top is bending at a different rate to the bottom and so pushing out the top helps in some places while pulling in at the bottom helps at others (particularly at bulkhead 1)

Attachment 117202

Fourth and fifth piccies - a boat is ... assembled ... sort of

Here she is in all her glory - she's too big for me to be able to get all of her in one shot. Man there are some forces in there. She's only held together with clamps at this stage and I've made no attempt to square things up. The strap is very difinitely doing things at this point.

Attachment 117203

Interestingly, bulkhead 4, the one just in front of the transom, went in best by being pulled down rather than have the sides pulled against it (see the big clamps).

Attachment 117204

So there she is, my own personal, pocket battleship. I can't get past in front, I can't get past behind and I'm too old and rotund to enjoy climbing underneath her all the time.

As noted earlier, this isn't a boat that you could assemble on the floor, so I've used saw horses - one at the front and two at the rear (because initially, she splays wider than a single saw horse).

The plan is to let her sit and get used to the idea of being this shape overnight, then attempt to screw things together tomorrow after which I'll give some though to how I'm going to glue it together. The curious mix of twisting and bending forces makes the whole 'let's grease it up with epoxy' scenario a little scary Whether I attempt to do one bulkhead at a time or whether I just pull it all apart and start again will depend on what I discover tomorrow morning.

Richard

(click on the pics to get bigger versions)

Keep at it Richard, you are doing fine, and teaching me a lot - especially not to be afraid of the timbers. Thanks

soth

Looking nice Richard....don't forget to make sure there is ZERO twist in the hull. Also, remember when fastening that if the screw is not square to the two surfaces being pulled together that they will slip out of alignment. Is the inwale glued? It'd be good to bend the outwale or rail around the boat to see if there are any high spots that need to be better faired. You may already have a sense for this and it looks fair from my seat.

Clint

Glad it bends OK. I was worried that the inwale being glued on early might make it difficult or make the ply bend in strange ways.

Congrats Richard
MIK

Fine! Good job!

Originally Posted by Boatmik

Glad it bends OK. I was worried that the inwale being glued on early might make it difficult or make the ply bend in strange ways.

Congrats Richard
MIK

That had me concerned too ... but there was always the option of a sharp plane

It's going to be interesting to see if I can glue it together without pulling it apart first - I suspect not and will find out for sure in an hour or so

My other concern is the one about twists that Clint raised - how to make sure she's not twisted. The old 'lay two battens across the top and sight along them' springs to mind ... except I lack the room to do this properly (can't get past either end). Again, this is all stuff I'll work out as I play with it this morning. I guess anywhere within coo-ee of straight is good enough at this time as it won't become fixed until the seat tops and bottom are on but I'll be aiming to get it as close as possible.

Richard

Every step it is good to check twist because it is more and more locked in with every piece of structure that gets glued in place.

Level two sawhorses, make sure they are parallel with each other, then put the boat on the 'horses. Be sure the centerline of the boat is square to the sawhorses. The boat should sit equally on all four points. I use this trick to be absolutely sure that boats are stored with out twist, except I do it more by feel. In building, measurements are good because the boat is still too flimsy to do it by feel. Another way could be to measure accurately diagonals, like from the bow aft to each transom corner. The measurements should be exactly equal. You really don't need to have a lot of room, however, to use the sighting sticks trick. Just stand right at the bow and transom and put two sticks (make sure they are straight!) maybe at the forward bhd and aft one or even closer to the centerline.

Spent the afternoon stuffing up my back and filling every bit of available space in my shed

As you can see from earlier posts, I had the boat assembled dry and decided to have a go at gluing things together from here rather than disassembling it and starting again.

First step was to check the gap at the bow. I'd made the stem piece as per the plans but it was clearly too fat for the job. To do this, I eased off on the bolts holding the bow together until the sides just started to part. A quick measure of the gaps showed that the stem wanted to be 22mm at the top tapering down to 15 at the bottom (as opposed to 26 and 20). More shavings later and the stem I'd prepared earlier now matched those numbers

Next step was to unfasten the bolts holding the nose together. I started with the top bolt - this was really dumb as it's the top of the boat that's got all the additional curve and by the time I had the top two bolts removed, the plywood side was trying to break itself at the third bolt down Still, I got it apart and here's what it looked like
Attachment 117259

You can see the way it splays out at the top.

I used a quick clamp to pull the top together (it's a bit hard to see in the first picture, but it's there) - some screws stopped it sliding down the slope. Some goop on the timber and here's the result - one nicely glued in stem piece

Attachment 117260

Attachment 117261

There is a lot of force on here and I really don't think that fitting the bow piece when the rest of the boat is assembled is such a good idea. Rather, I suggest you join the bow (as in glue it in) with the sides free, then dry assemble the rest of the boat, then proceed as I've done here.

Next step, bulkhead 1 (see next post)