Hybird MF14

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Bogieman
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Re: Hybird MF14

Post by Bogieman »

:lol:

OrangeQuest

Re: Hybird MF14

Post by OrangeQuest »

Chenier wrote: Thu Jun 21, 2018 5:44 pm The longitudinals are cut and trimmed. Bow and trunk sides on the left, aft stringers on the right.

There are two trunk sides and two aft stringers - the pairs were cut stacked so that both sides of the boat would have the same mistakes. The boatbuilding literature calls this "symmetry".


They're laying down on the job!
I make my cuts one at a time. I make so many mistakes they multiply! :oops:

Everything is looking very good!

Chenier
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Re: Hybird MF14

Post by Chenier »

I tackled trunk/bow stringer assembly. This is a slight departure from the build notes which would have me lay out the deck next. As you can see from the photos my garage shop doesn’t have a lot of extra room, so I’m doing as much as I can before erecting a big 4’x16’ worktable.

Here I’ve cut cleats for the mast step and daggerboard from cypress and added lightening holes to the big plywood parts. The lightening holes are partly to save weight but also to allow some air circulation during the months the boat will be in storage. The build plans say “Respect minimum 2” offset” for lightening holes in the frames. That seems like a good guideline. In addition I’m keeping 2” between holes.

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Kindly ignore the limber holes some idiot cut on the deck side of the stringers. Thank you. The working limber holes are on the hull sides of these pieces.

Next is a dry fit of the assembly. It took a while to get everything square and clamped into position. Then I drilled through at each of the cleats and pegged the assembly with 1/4” red oak dowels. That holds it square and let me put each component exactly where it belonged when epoxying.

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This photo is the way the whole structural frame gets built - upside down on a flat deck.

The epoxy step was a bit of a mess, in part because the last time I fooled with marine epoxy was about 20 years ago. I’m trying out SilverTip because the manufacturer says you can let it sit for 72 hours before needing to sand when putting more epoxy over it. Everyone else says 12 hours - even the same manufacturer’s other brand of marine epoxy.

Before assembling everything I coated the inside of the trunk sides with epoxy so I wouldn’t have to get into that slot later. Then came a small frenzy of epoxy gluing and fiberglassing. There was enough play in the structure that the final piece, the starboard trunk side, might not line up with the dowels if the epoxy set firm. Fortunately, using slow hardener, there was enough flexibility after 1.5 hours to get that piece in place and then clamp everything:

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In this photo the deck side is up.

The Build Notes say to fiberglass inside of the mast step and inside the daggerboard slot. I used the method recommended in Gougeon Bros. book: Lay a piece of fiberglass around three sides of the hole. Apply a second piece to the fourth side, then close up the assembly. In retrospect it would have been much easier applying the glass as four pieces - one for each side of the hole. Except for the bow side of the mast step, all the glass could have been applied to its appropriate component the day before. Live and learn.

Bogieman
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Re: Hybird MF14

Post by Bogieman »

Nice bit of progress. She's looking good so far.

Bogie

walkabout_slp
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Re: Hybird MF14

Post by walkabout_slp »

Chenier,
Nice progress so far.
I am hopefully finishing my boat before the end of the summer so feel free to PM me with any questions.
I made many a mistake so far, some documented in my build:
https://forums.bateau2.com/viewtopic.php?f=13&t=62869

walkabout_slp
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Re: Hybird MF14

Post by walkabout_slp »

Are you going to do strip planking on the sides and bottom of the boat too or just the deck?
The reason I ask, is that I believe from experience (built a cedar strip canoe 20 years ago) that strip construction needs fibreglass on both side's of the strip for strength? Or am I not remembering it correctly?

Chenier
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Re: Hybird MF14

Post by Chenier »

You are remembering correctly. According to the Gougeon Brothers book, p. 275 says 6oz cloth over both sides of Western Red Cedar strips has equivalent breaking strength as marine ply.

I'm planning on cedar strip just for the deck and [top]sides. They'll be finished bright. Bottom will be painted so there's no point in getting fancy. Inner frame and bottom will be marine ply as per the plans.

Chenier
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Re: Hybird MF14

Post by Chenier »

It’s been a while. Spent the rest of the summer and early fall using and repairing other boats. Now it’s time to get back to the Moonfish!

In this phase I’m working on the long, skinny parts. The 24-inch wide worktable is extended to 15 feet for cutting the side and bottom panels. I’ve also built an overhead storage rack to hold said long skinny pieces out of the way until the build is ready for them.

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Side panels were next up. As mentioned earlier these will be “strip built”: made of 1/4-inch x 3/4-inch cedar strips edge glued together. Later in the build these will be sandwiched in 6-ounce fiberglass and epoxy. This is the "Hybrid" in Hybrid MF14. Some kayak and canoe builders use this technique to produce compound curves and stunning designs. I’m using it just for the looks. That gives me some leeway in how I do the strip build. While borrowing heavily from the strip builder’s toolbox I’ll take advantage of the fact that the Moonfish’s deck and sides start life as flat panels. The deck stays flat while the side panels take a simple curve in one dimension (the long way.) I’m building these panels flat and will bend the sides into place later in the build.

The strip builders construct their craft on molds spaced one foot apart. I’m in no position to argue so I set up MDF molds with that spacing. Rather than using staples or hot glue to conform my strips to a curve, I’ve set up each mold as a little panel clamp to keep the panels flat.

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The strips themselves were obtained from a supplier of strip-built kits so I didn’t have to cut them myself. These are flat panels therefore no need for bead and cove. Since the strips are only about seven feet long I’ve joined them lengthwise with scarf joints. They’ll need to hold together when bent onto the side of the boat, so 8:1 scarfs. Strips are glued together one at a time with TiteBond, the favorite glue of strippers. In the above photo the eighth strip was just put in place. You can see the extra clamps for a scarf joint about half way down the table. The tape between molds helps compress the strips together - TB doesn’t like gaps. After an hour the tape and clamps come off and another strip gets added.

In theory if one were a perfect craftsman there would be no difference between the panel’s two sides. But I’m not such a craftsman so there’s a distinct difference between the side I can see while I’m building and the side I can’t see. Therefore the side I can’t see becomes the “inside” to hide my sins. Here’s the port side panel all glued up:

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Then I reversed the molds to glue up the starboard side.

Once both sides were glued I stacked the panels back-to-back and taped them together so I could cut them as one. Here I’m laying out the curve of the bottom:

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Et voila! Two side panels.

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There’s a bit of scraping and sanding in my future to knock off the squeezed-out glue and fair the surface...


Bogieman
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Re: Hybird MF14

Post by Bogieman »

8)

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