resizing/stretching a stitch and glue design

Maybe I should have used the term "Stations". Mine is built on a strongback on stations something like this.....



Yeah of course it would have helped to know which boat and the size you were building.

Just splice in the extra 10% at the widest part. Let the plywood define the shape of the hull and fix any gaps with goop & glass. 10% on a 16' boat won't make that much difference (19").

 

There isn't one, see post #4.

That adds a cylindrical section midships; it assumes the hull seams and sheerline are all parallel to the hull axis at the same station.

Eight weeks seems a long time: I think he's left ... not everybody can handle Hoyt's sense of humor ...

About S&G: I agree the laying out and drilling is a pain but the worst part is trying to cover all the stitches with epoxy then having to sand them down ...

 

Ok, here is a method that is fairly accurate for small changes in length. Lay a batten on the sheer and mark off the station locations. This will show the actual length along the sheer between stations of the S&G plan layout. Increase these individual dimensions by the desired 10% on the S&G layout. Note that the actual amount of increase will be different for the different stations. Do the same for the chine and keel. Fair (loft) the new patterns by any acceptable method.

The result will not be perfect but will be close enough to allow the new patterns to fit well and will not distort the hull shape.

Terry, if you are having trouble covering the stitches, the solution is to epoxy tab between the stitches and then remove them before laying in the whole filet. A good application tool and technique is part of a good filet job. There is no reason that filets should have to be sanded if done properly. The solution is to lay on the fiberglass tape(s) before the filet sets up and clean up all epoxy dabs. If there are runs, you are using too much epoxy. On big filets on larger boats, use peelply to avoid sanding. Epoxy joinery is messy enough without adding to the work or mess more than necessary.

 

... maybe if it's a canoe or somesuch. We really need to see the lines to be able to advise further with any certainty.

Agreed, that would be the method I would use if I did S&G; keeps the fillet size down, which is especially important for neatness if the angle between the planks is getting close to 180 deg. I watched a buddy of mine trying to get epoxy fillets done neatly with the stitches in place: he's a former professional furniture maker and is obsessive about finish, and he was so discouraged by the results that the boat is still unfinished after several years.

Most hardware stores sell a nice, cheap plastic tool for forming tidy fillets, it's intended for smoothing out caulking and bath tub sealant.

I haven't used peelply but I'll bear it in mind. I have used chine logs for several years and in general I minimize epoxy - I'm cheap but epoxy isn't I have read that the seams can be held together with dabs of super glue while the stitches are removed, but I haven't tried that yet. I assume that would be the thick variety as the thin stuff would vanish into the grain.

I've seen videos of the pros shaping the fillets - with masking tape to get constant width - it's true artistry but my hands aren't steady enough to do that. I was into calligraphy way back, even used to do custom certificates for special occasions, until I damaged some nerves in my hand a couple of decades ago - had to learn to write left-handed - so one of my fillets would not be a thing of beauty!