Thread: questions about stitch and glue technique

Some answers from someone who's not the world's greatest fan of stitch and poo.

1. Epoxy needs glue between the two surfaces to work - it's actually a gap filler, which is why it works with methods like this and for rubbish carpenters like me. Joints can fail if you clamp them too tightly and force out all the glue. However, fussing about with sticks to create a gap between two bits of a boat just seems like complicating something that doesn't need to be - you are NOT going to get airtight fits with a stitch and gule boat. Similarly for bevelling one plank. The two boat bits will not fit perfectly, you're filling the gap with poxy, adding a fillet and then whacking glass tape over the outside - how much strength do you need? The joy of stich and glue is that it's easy and quick, there's no need to make it complicated.

2. Glue the boat together, cut the ties flush with the surface and forget they ever existed. If you pull them out, you've got a hole to fill ... that's assuming they'll come out at all, poxy works because it sticks to things. One method is to tack the hull together with dollops of poxy, remove the ties and then do your filleting, if you're worried about the ties, that's probably a better method but it's not hard to fill a hole using a syringe.

3. If you're not building from a precut kit, I can't see why you'd bother with Lapstitch. [grump] Building a planked boat over frames is so easy, I really fail to see the need for the complications of laptstitch. To me, it's just a way for people to avoid boat building techniques that seem scary and complicated but which are, in reality, simple and forgiving. The yanks in particular (but they're not alone) are fond of making simple things complicated in the apparent belief that this somehow makes the exercise worthwhile. Arron, if you're buying a pack of precut pieces, go with your lapstitch, if not, build the poor boat properly in the first place. Glued lapstrake boats (such as Oughtred and Payne design) do no need gallons of poxy to hold them together, they don't need fillets, they don't need tape and they are simpler than these weird lapstitch creations. All they need is a bevelled landing on one plank (where the two overlap) and a rebate at the ends, both of which are cut by eye with the plank on the boat. Similarly, planks are cut to fit the boat, not the boat forced to fit the planks which is what you're doing with any stitch and glue method. Yes, you can assume I've spent too long on the Wooden Boat Forum watching people make hard work of building boats and there are too many manufacturers making money out of that attitude. Either buy a precut kit or better still, do yourself a favour and build one of Oughtred's Acorns.[/grump]

Richard

Generally in "Liquid Joinery" methods (taped seam, stitch and glue, etc.) the joints don't have to touch. If they do, it's no big deal, but as a rule you want sloppy fits, to offer space for the epoxy fillets to live. Finely fitted joints don't provide this, though you can make up the difference with slightly larger corner fillets inside the boat.

Leaving in the ties saves some bother. In reality it doesn't matter much. I personally have stopped using these methods, preferring toward a "constrain and glue" method of my invention. This is basically holding the panels in position, by any means necessary so I can apply the interior fillets and tape in one smooth, continuous shot. This saves the bother of filling holes, having a patch work of fillets and tape to mend, etc.

Back to your question, which ever you like works. Leaving them in will not weaken the properly sized and applied fillets, nor will removing them. If using wire, I'd recommend removing them, just because they don't sand at the same rate as surrounding material.

The Lap Stitch method is one of a handful of ways to get the lapstrake look. Again, I don't bother, just glue the bugger to the preceding plank and move on. This method is called "glued lap" (no bevels or laps) and is a great and strong way to produce a light boat. The half lap can offer some alignment help, but I've found either a plank fits or it needs to be trimmed. If it needs trimming (they always do) then the half lap isn't much help, so why trouble yourself.

I use a mixture of traditional lapstrake methods to do glued lap. I don't drill and "pin" the laps with fasteners (any more), but use battens as landings and clamping arrangements. I've found it's very easy to move a light piece of plywood with a fastener, but a strap or clamp can be infinitely adjusted to resolve any distortion issues.

Damnit Daddles beat me to it . . . Hay! who's afraid to build a boat!

Arron, I have limited experience with this, specifically 1 almost complete Jem kayak. However I can say that having used the spacer method I will do so again. Spacers make it easier to obtain even fillets and hold a gap that allows the right radius to be created between the 2 panels. I used 3mm spacers and dark fillet material to make the fillets a feature rather than try to hide them (it worked).

It has already been said that you can do either and I agree with that as long as your reasons for the choice are right. There are experienced builders who don't use the spacers but I know of one who says he is going back to that method next time.

Final comment: It's a good idea to follow the instructions that come with the plans (no matter what brand) - the only time I ran into real trouble during my build was when I tried to get creative and ignored the instructions.

Good luck with it whichever way you go.

I've always aimed to get the edges very close ... the edges are where the fairness lurks and there is a good opportunity to get the internal edges fairly joined along their entire length. Very little daylight at all.

Not really opposing the views quoted ... but just finished two Eureka canoes and you can get very accurate joins this way. One of them was computer cut so had a very high level of accuracy.

So would suggest that you can do it either way successfully. I think the spacer version is not very common compared to no spacers ... so not "essential" by any means.

Damage when removing wires ... we decided to remove the wires for the two eurekas ... no damage at all. Just snip off the wires close and pull them out. As Daddles points out ... it is more steps and processes. No harm either way ... we know both work ... so do it the way you want.

Stitch lap ... if you like it ... why not? I don't think the argument for classes holds water ... stitch boats without laps have been hugely successful for decades of classes and a bewildering variety of boats ... so I don't think it is a realistic advantage.

Additionally it does mean that you have to buy a relatively expensive kit rather than having the option of just buying the ply and marking up yourself.

We did have one boat using a somewhat similar method - a dinghy just over 11ft at one of the classes a few years ago ... it fell well behind every other boat because other aspects apart from the hull shell of it were much more complicated than necessary - more bulkheading to try and get the right angles between planks along the length of the baot.. I think you have to look beyond one feature when choosing suitable boats to be built in a class situation.

Best wishes
Michael Storer

I have built them both ways and more often than not, using a combination of both in the same boat.

This helps me to compensate for my inconsistencies in my panel trimming and to achieve "fairness' along the seams. Sometimes, for me, itiis also handy to have a few little wedges as well.

I agree with Mik, Both methods are fine.

Re the wire, I remove it. My 1/16th" holes are not filled, I remove all tie wire and just leave them and the successive applications of epoxy takes care of that for me - easily.

Originally Posted by labr@

Final comment: It's a good idea to follow the instructions that come with the plans (no matter what brand) - the only time I ran into real trouble during my build was when I tried to get creative and ignored the instructions. .

Normally I'd agree with that, might even say it myself. However, the plans for Redback were so rubbish that the boat didn't start to come together until I ignored them and started using the techniques I'd learnt at boat building school This is why some of us don't mind paying for good quality plans rather than buying an alternative because it's 'cheaper'.

Richard