Question on mould stations for Joel white flatfish

[jacobcam]

I have bought the plans for the flatfish as well as the book on the haven build, and am now in the process of going over the various steps to be taken. I've noticed in the plans that the construction measurements are given for every second frame. Is there a set in stone method for making the construction moulds for these? It seems it would be counter-intuitive to bend them in place after the planking was put on.

[Peerie Maa]

no reason why not, lots of boats are timbered out after planking is complete.
Make as many moulds as you need, then timber in between the moulds, take the moulds out and timber in the gaps.

[jacobcam]

Start upside down get a good fit with half the frames bent- then flip the boat over and try and bend and twist additional frames into place- flip boat over again and finish fairing and bunging- flip the boat over again to paint and fit out interior...there has to be a better way i don't buy that.

[Peerie Maa]

Start upside down get a good fit with half the frames bent- then flip the boat over and try and bend and twist additional frames into place- flip boat over again and finish fairing and bunging- flip the boat over again to paint and fit out interior...there has to be a better way i don't buy that.

Boats always used to be built the right way up. ‘
If you don't want to do that, loft the boat and lift the shape of all of the timbers, take off the thickness of the plank and timbers. Make moulds. Then bend the timbers over the moulds and plank up.

[outofthenorm]

Assuming that you are building right side up, the process normally is to erect the moulds on the stations defined in the plans. Then set up ribbands to get the full fair shape. Next bend in the intermediate frames between the moulds and against the ribbands. Several ways to go from there, but I would be inclined to put in the shelf and or clamp and bilge stringers (if any), as many floors as possible and plenty of cross-palls, then remove the moulds and finish framing. The ribbands come off as planking proceeds.

[Peerie Maa]

Start upside down get a good fit with half the frames bent- then flip the boat over and try and bend and twist additional frames into place- flip boat over again and finish fairing and bunging- flip the boat over again to paint and fit out interior...there has to be a better way i don't buy that.

So, how were you planning to flip a 20 by 7 foot hull?

[jacobcam]

I would think Joel white would build this boat the same way as the haven was built. Full size plans and time spent of the smaller of these two makes more business sense as its more practical for the amateur to build. I also think its easier to make the rabbet on the keel and do a better job while its upside down and rigidly being held together by construction moulds. Would it not make more sense and save time to lay battens across and make patterns in between the moulds to then double up the framing? has this not been thought of. I would rather that then have to determine running bevels on three sides of floor timbers, bevels for the end of the frames to match the keel and twist it in shape while its cooling and levelling them up along the planking while trying to fasten them.. and then be crouched for a few days bunging and sanding.

[Peerie Maa]

I would think Joel white would build this boat the same way as the haven was built. Full size plans and time spent of the smaller of these two makes more business sense as its more practical for the amateur to build. I also think its easier to make the rabbet on the keel and do a better job while its upside down and rigidly being held together by construction moulds.

The backbone must be rigid which ever way up you build her. The keel rebate can be cut taking its angles from the moulds, whilst the shape of the stem rebate comes from the loft floor.

Would it not make more sense and save time to lay battens across and make patterns in between the moulds to then double up the framing? has this not been thought of.

That will involve trying to work under the battens in amongst the moulds if you build upside down. You would need to be a contortionist. Easy to do building the right way up. The best way to build upside down is to take off the plank, frames and battens on the loft floor, so that you can steam the timbers over the battens rather than inside them.

I would rather that then have to determine running bevels on three sides of floor timbers, bevels for the end of the frames to match the keel and twist it in shape while its cooling and levelling them up along the planking while trying to fasten them.. and then be crouched for a few days bunging and sanding.

Boat building is all about bevelling floors, and twisting steamed timbers has gone on for centuries. You can bilge her over to bung and flog off, to lessen the time bent over.

[Bill Wiegmann]

When I built my Haven, there was a full size pattern for each mold and a mold for each frame. I set up all the molds on the building frame (building upside down), then faired the molds to put on the appropriate bevel and steam bent the frames around each mold, twisting and clamping them in place to conform to the beveled edge of the mold. This is what the How to Build the Haven 12-1/2 book called for.

If I had been provided with only mold patterns for half the number of frames required, I think I would have (1) set up all the molds I had, (2) faired the molds to put on the bevels, (3) notched the molds for ribbands that would effectively span the gaps between the molds, (4) steamed the frames for each of the molds and (5) then steamed the frames for each of the intermediate stations, clamping the frames to the outside of the ribbands until they cooled. I am not sure how many ribbands would be required; the Haven frames, at least, had some twist in them and you would want enough ribbands to hold the frames in place with that twist.

[Ian McColgin]

The Haven 12-1/2 at Pease had the frames steamed and clamped to the molds before any planking. Here during the post Maine Boatbuilders Show LastBoat state visit Mary Bauer and - forgive me I'm blanking on the name but someone will fill in - are viewing. If you look you can see the thin little frames in contrast to the mold station wood. One of the clamps is visible about half way along the boat near the bottom of the pic.

[Ian McColgin]

A broader view of same with Dave Lesser posed in the foreground. Shows more of the L clamps. At the bottom (gunnel) the frames when steamed were first pressed between the mold and a squared off U clamp, bent in place, and then brought at that place against the mold with a wedge. Then the L clamps were added. There's a video of that steaming process on the Pease Boat Works web page. There's also a gorgeously filmed minute and a half of getting one of LastBoat's frames in. The former from outside over the mold. The latter from inside against the ribbands. Illustrates two different approaches mainly dictated by the size of the boat.

[Ian McColgin]

Hot wood. There's a reason to wear gloves. Brendan is inside, Chris (visible) and Dave (hands) working from outside.

[jacobcam]

Definitely a few ways to go about it. I think the using ribbons would result in a cheaper quicker setup but maybe a harder time translating proper twist in the frames. I think making the moulds with patterns would result in more time and cost initially but would be more accurate and easy in end installation. Just going about out it on the fly would require no cost but a second pair of hands and maybe a more rushed result not suited to an amateur.

[113bob]

The Flatfish is designed to be built in the "Herreshoff Style" - upside down, with a mold at each station for every pair of frames. Since you need to loft the boat anyway, it is a simple matter to derive the shape of the odd numbered molds once the lofting is complete and fair to your satisfaction. Draw the odd numbered stations on the profile and half-breadth views - the 9-3/4" spacing is consistent - and they are straight lines in these views. Pick up the points where each crosses the waterlines and buttock lines and transfer these to the body plan. Fair these as you did the others and there you are. Deduct for the plank and frame thickness and that is the shape of the mold at the station line. That's what I did.
All that being said, if you are going to strip plank or cold mold the boat you may not want or need as many frames.

[Ian McColgin]

How you do the frames, from inside against ribbands (#13) or from outside against the station molds depends much on size and design. LastBoat's gentle curves and general size made the ribband approach better. With that method the frames are twisted into place and thus take the correct angle to receive the planking. Mostly. Some catboats built that way end up with frames near the bow that are emphatically not normal to the centerline but that jarring look is hidden under the deck. But for most small boats, it's easier to put the frames on over many more and closely spaced stations. The frames are then carefully planed on the outside to take the lie of the plank. In the smaller boat, that rolling bevel is far easier to do than any attempt to get the frames to make sense pressed out against ribbands.

Below is a close-up of the gunnel wedging for installing the frames on the Have 12-1/2 at Pease. The hot frame is placed against the station at the gunnel under that U, then wedged firmly, and then bent.

[belviderewoods]

What 113Bob said. Note that this method specifies that half the frames are clamped ("dogged," actually) to the molds before planking, while the boat is upside down. Floors are then riveted to those frames. After planking, with boat turned right-side up, the remainder of the frames are steamed and driven in, with their floors then screwed to them. All of the boats built with this method (the Herreshoff Manufacturer's Method) have the characteristic that every other floor is screwed from the keel into the floor with frames riveted to those floors (those are the frames that were applied directly to the molds,) and the remaining floors are screwed from the floor into the keel, with the frames screwed to the floors (those being the ones installed right-side up, after planking when there no longer is working clearance to set rivets.) Buy this book:

http://www.amazon.com/Building-Herre.../dp/0913372331

It explains the method in somewhat more detail thatn"How to Build the Haven 12-1/2 Footer" does.

[jacobcam]

Ill have to invest in that for sure...I like the idea of creating the moulds as it will be just me working on it and this method wouldnt rely on a second pair of hands

[jacobcam]

On a side note how is the end product compared to the haven..I have a 17ft open dory and I am really drawn to the beamy cockpit somewhat ease of launch for the amount of boat you get

[belviderewoods]

The fish class is based on the same half-model as the 12-1/2. BUT, there are big differences. Even though the LOA of the Fish is only 4 feet more than the 12-1/2, the Fish displaces twice as much and so, in every meaningful sense, is twice as big. Neither of them, in my opinion, is anything like an open dory. These are much more complex boats to build and "bigger" boats to handle than your dory. The Joel White variants (Haven and Flatfish) both do away with the original full keels in favor of slotted keels and centerboards. This makes them easier to launch and retrieve but I would not consider either to be a "trailer sailor," especially not the Fish. If you're looking for something comparable to your dory in terms of trailerability, ease of launch, rigging, handling, etc. I think you might want to reconsider your choice of design. Flatfish are pretty rare, but Havens are fairly ubiquitous. You might look around up there on the big lake and see if you can find one you can bum a ride on to get an idea of what you'd be getting into. They are WONDERFUL boats, but they ain't Dories.