A Hvalsoe Dinghy in New Zealand

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

Thanks, Alex.

[Eric Hvalsoe]

Re: A Hvalsoe Dinghy in New Zealand

Probably not much help, but I recall cold bending CVG Doug Fir for the keel and apron(keelson) on some 13's. It's been a while. The aprons were a mother, narrower keel not so bad. The Fir was dry. Thorough bracing of the last mold and transom. The curve is whatever you get (while touching molds and transom) - This may look a little different then the lofted line. Pattern the skeg to the bent parts. I mentioned thinning the apron a little (still leaving adequate meet for nails).

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

Thanks, Eric. I should have left a bit of extra wood on the inner curve of the skeg, until the curve was established to pattern it off, like you say. I can probably trim it a bit to fit.

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

I have laid the keel!!!!!

I steamed it in the plastic tube,
P1040188.jpg

and glued it with Gorilla polyurethane glue, with a prop between moulds 8 and 10.
P1040195.jpg

and cleaned it all up the next day. The steaming didn't really make much difference.
P1040199.jpg

Yesterday I did some more experimental steaming of macrocarpa and southern silver beech, and decided that I would use beech for the planking and elm for the frames. The beech would have been good for the keel and keelson too. My book says it was extensively used in the past for building motor bodies, due to its excellent steam bending properties. I will have to get it from the sawmill at Tuatapere in Southland. Its Latin name is Nothofagus menziesii.

Today I made several trial attempts at cutting the stem rabbet in some old scrap timber. I have seen this demonstrated at Port Townsend, starting with a circular saw cut along the middle line, a little shallower than the final depth. I did that, and did the rest with a chisel and my rebate plane with the blade in the front position. It was good to get the feel of this operation before doing it on the good timber. My stem is elm.
P1040205.jpg

It's good to see some progress at last.

Cheers,
Ian

[Alex1N]

Re: A Hvalsoe Dinghy in New Zealand

Southern beech for the planks sounds very interesting. Interesting that you used polyurethane glue on a area under moderate tension. I've only ever used it on relatively unstressed items, and wouldn't have thought to have used it on a keelson, for example.

Looking great! .

Cheers,
Alex.

[Andrew Donald]

Re: A Hvalsoe Dinghy in New Zealand

Must feel good to have the keel done. That glue was made for steamed members, means not waiting for timber to dry out. Best of luck for sorting your timber search Ian.

[Alex1N]

Re: A Hvalsoe Dinghy in New Zealand

Thanks for that, Andrew. Useful to know, will squirrel that away for a rainy day.

[Andrew Donald]

Re: A Hvalsoe Dinghy in New Zealand

Just be aware Alex, that is the glue that foams when it has a gap to expand into or out of. The expanded foamy residue doesn’t have much strength so your wood needs to be a good fit. I used it on my laminated deck beams and it has worked well. But those strips were planed smooth to fit together well. I damped down the wood a little to aid curing.

[Max F]

Re: A Hvalsoe Dinghy in New Zealand

Good progress Ian

At the rabbet a compass rabbet plane comes in very handy.
We modify wooden rabbet planes.

Cheers
Max

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

Thanks, guys. I didn't get any done today but expect to cut the rabbets tomorrow. Andrew is right to say that polyurethane glue can be used on damp wood, although it was really because I don't want to be mixing epoxy all the time. Also because it is not dependent on the temperature for setting. The keel to keelson joint is two large surfaces in continuous contact, tightly clamped together while the glue cures. If there are any gaps in a joint the foaming glue will fill them and keep the water out but will not be strong structurally where the gap is. Andrew said it better.
Thanks for that good idea, Max. I found in my trials that my old Stanley rebate plane with the blade at the front position tidied up the chiseled rabbet line pretty well.
Cheers,
Ian

[Alex1N]

Re: A Hvalsoe Dinghy in New Zealand

Just be aware Alex, that is the glue that foams when it has a gap to expand into or out of. The expanded foamy residue doesn’t have much strength so your wood needs to be a good fit. I used it on my laminated deck beams and it has worked well. But those strips were planed smooth to fit together well. I damped down the wood a little to aid curing.

Thanks Andrew. I must have used a similar thing when I did the foils for Wood Duck - that was a foaming polyurethane glue called Purbond, made by Bote-Cote (Boatcraft Pacific). (I wrapped them in glass and coated them with West 105/207 then Norglass clear marine enamel.) The staves were glued together as machined (also from Boatcraft), very smooth finish.

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

Progress has been slow lately.

I steamed some more samples of macrocarpa and silver beech. When I tried to twist a piece of macrocarpa at the forefoot it split, but the silver beech took it very well, as shown here, so I will see about getting that for the planking. I have enough elm for the frames, and will get some macrocarpa for the thwarts when I'm ready.
P1040206.jpg

Here is the stem rabbet, with the knee fitted. The relevant measurements match the lofting, but the angle of the stem is slightly different, so
the knee needed some trimming, which is a bit of a puzzle.
P1040211.jpg

The transom knee fitted better.
P1040213.jpg

I cut my last oak bed-end into its three boards along the joint lines (as I don't suppose the original glue was waterproof), added the last piece of the previous one, and glued all four together with epoxy splined joints.
P1040215.jpg

The next day, I ground the corners off the blade of one of my planes, sharpened it up, and planed the whole thing flat on both sides, working across the grain first and then along it, which came out pretty well.
P1040221.jpg

I have also been studying all my books again for what sort of glues and sealants to use, and they all say different things, sometimes in brand names which you don't get here. Epoxy for the transom joints is used by Will Stirling in "Details of Dinghy Building", who also uses Gorilla glue in the hood-ends and the garboard-to-keelson seams before he puts the fastenings in. Ian Hugh Smith in "Wooden Boatbuilding - The Sydney Wooden Boat School Manuals" uses a bead of "low modulus polyurethane" (e.g., Sikaflex 291) in the ends and laps, making a seal but allowing the wood to move. As I will be using clenched nails for the planking, I think I have abandoned the idea of being able to take any part out and replace it easily, and I don't want to have to soak the boat in the sea to make it watertight.

That will do for now....

Cheers,
Ian

[Thad]

Re: A Hvalsoe Dinghy in New Zealand

That will do very well. I'm off to WBS today. Best to you two.

[Alex1N]

Re: A Hvalsoe Dinghy in New Zealand

Not so good that the macrocarpa split, but great that the southern beech is a goer for the planks. I’m really interested to see how the beech turns out. Good to see the (last of the) old bedstead(s) being usefully repurposed.

Cheers,
Alex.

[IanMilne]

Re: A Hvalsoe Dinghy in New Zealand

Thanks for that affirmation, Thad. Good to hear from you. All the best for your class, from both of us.

Hi Alex, Macrocarpa is described as a good boatbuilding timber except that it cannot be steam-bent, or words to that effect, as with other softwoods (except cedar, apparently). I got some bending out of it, but I was pushing my luck a bit there. Southern silver beech, according to my timber book, "has been used extensively for motor body building, due to its excellent steam bending properties", so there you are. (I don't know what sort of motor bodies. They must have been the old ones.) I could probably get kauri, at great expense, but that's not necessary. Ian Hugh Smith (mentioned above) lists various Australian boatbuilding timbers under names such as "silver ash" and "white beech" which are really eucalyptus species. Your "spotted gum" has been used a lot in New Zealand for steamed frames. (In New Zealand we describe eucalypts by their Latin names, to avoid confusion.) You also have those wonderful Tasmanian "pines", which we don't get here.

Cheers,
Ian