Building Dave Gentry's "Annabelle" SOF Sailboat

Discussion in 'Boatbuilding' started by lewisboats, Dec 8, 2013.

  1. lewisboats
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    lewisboats Obsessed Member

    finally took the plunge and laminated the gunnels into their prebent form. The method is to take the 3/4" x 1 1/2" strips and kerf them twice, almost to the middle on each end, allowing them to bend without cracking. You then form them and glue them up. I put about 11" of prebend in mine so after springback they should come in at around 10". The basement is chilly so I'll give them a good long time to cure.The roll of Vinyl is to even them out so the bend is the same for both... I think one of the bungees is slightly weaker than the other.

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  2. lewisboats
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    lewisboats Obsessed Member

    Those didn't work! I ended putting too much curvature into them and I need to redo them. This time I'm gonna cut 3/4" wide by 1/2" thick strips and laminate in place instead of trying to do it off the build. Thangs just ain't goin' well with this build.
     
  3. rwatson
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    rwatson Senior Member

    Dont sweat it, problems is normal. I heard that there was one guy, once, who had a problem free boat build, but he ended up being killed by friends who got sick of his constant gloating. :p
     
  4. lewisboats
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    lewisboats Obsessed Member

    Finally... I have gotten past my builder's block and am making a bit of progress. My parts didn't seem to want to go together Dave's way so I kind of reversed the order. I am building from the bottom up so to speak. I welded the frames to the keel with epoxy, then installed the bottom stringer, squared up and filleted it in. Now I am working on the others. I managed to tweak the Stem back to straight with some water and considerable reverse twist. Not going to get to take it on my first vacation trip but I am still hoping for this year's Sail Oklahoma. I am still a bit concerned about one of the stringers snapping. I sprung the top one yesterday and clamped in place. As I was at the bow between the two crossed ends the clamp slipped (holding the cross together) and I got slapped in the face with a 1x3/4" stick traveling at speed. Knocked my glasses off and bent one of the arms along with knocking me (even more) silly. There be some tension in there...

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  5. lewisboats
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    lewisboats Obsessed Member

    Nasty weather outside which ruined my plans to clean up the back yard allowed me to do a bit more on the Bateau. So, with some APP blasting in the background, I fitted the other stringers. In the photo above I had forgotten that the top stringer was supposed to be the Fir instead of Cedar so I had to switch them. Unfortunately... as I was unable get ready made 1" thick fir and I would have had to manhandle a 12' 4"x4" to cut my own I opted to go with 3/4" and make it wider for approximately the same amount of meat. I cut the 3/4" piece to 1 1/8" wide instead of the called for 1" piece to 1"x1". As the deck/seat sits on top of this stringer the extra thickness should help rather than hinder. This required me to file down the lower edge of each stringer notch to fit the piece... about 1/2 hour of work.


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    Right now only the bottom stringer is epoxied on and just screwed to the stem... which is good as I have to tweak one side to pull it over a bit more. It is slightly out of plumb.
     
  6. lewisboats
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    lewisboats Obsessed Member

    Dry fitted some of the gunnel today... I am laminating it in place out of 3/4" x 1/2" thick pieces, that way I can control the shape of the shear better. My attempt at doing the gunnels off the boat didn't work out so good so this is attempt #1 on try #2. I got the ends of the stringers nipped down and attached to the stem, with the upper fir stringer screwed to the frames yesterday afternoon before going to work. Went and bought another 25 or so clamps of various kinds and sizes to add to my collection. You can see a bunch of them here. The spring clamps are keeping two layers of the gunnel together and lined up, while the vertical squeeze clamps are pulling it down into the notch, using the upper stringer as leverage. I'll be taking it apart again to glue the layers one at a time to the frames and to themselves. There is a lot of tension on the Stem when you attach the stringers and keeping it straight is.... difficult. I don't see it ending up ruler straight but seeing as the skin is flexible it shouldn't matter too much except for esthetics, which will be marred by the big (ish) bundle of cloth and stitching at the stem anyways. My recommendation for this build is to double the thickness of the stem to 1" using some of the excess 1/4" ply from the deck, or extra 1/2" purchased for that reason. You wouldn't taper the keel at the stem as much and would have to cut a larger slot but that would be the extent of work needed for that modification.

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  7. Dave Gentry
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    Dave Gentry Junior Member

    Looking good, Steve.

    These short boats are very handy and light, but building them is always a pain - they are still pretty beamy, which means that the longitudinals take some difficult bends. Laminating them in place, while messy, is a good option.
     
  8. lewisboats
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    lewisboats Obsessed Member

    I ended up cracking one of the fir stringers trying to get it to snug up to the stem so I'm going to gusset them behind the stem to keep things together and fillet it to the stem piece. It's still fighting me tooth and nail. I expect the stem to be slightly off plumb but not by much and it probably won't be visible after the stitching is done. I'll be taking a break on it for the next 3 weeks or so. I have some mods to do to a couple of other boats that I am taking on vacation the end of next week through the second week of June. I'll get back to it after that. I plan on ordering the cloth soon after getting back so I have it on hand when I need it. Still trying to source a sail. I tried Todd Bradshaw a couple of times but he hasn't contacted me back yet so I don't know if I got through. I wanted one of his multicolored sails but I might have to go with a monochrome one from Duckworks. I'm still hoping to hit the water late summer/early fall and bring it to Sail Oklahoma. Are you planning on going this year?
     
  9. laukejas
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    laukejas Senior Member

    I hope this won't be viewed as a necro-posting, since thread is 5 months old, but...

    Steve, how is it going with Annabelle? I'm considering to build it too, and the information you provided on your experiences proved most helpful. Are you still working on it?
     
  10. rwatson
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    rwatson Senior Member

    When you do yours Laukejas, see if you can put a light layer of fibreglass and epoxy on the outside of the bends in the timber, before you attempt a bend.

    Not only will it protect the wood, but it makes the bending process incredibly easy. Even problem wood will take a bend like a fishing rod.
     
  11. lewisboats
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    lewisboats Obsessed Member

    Still working at it. I am stuck on the transom right now, having decided to do a decorative pattern with veneers and I'm fighting with the veneers right now. I've been gone a week at Sail Oklahoma (just got back 1/2 hour ago) and the previous couple of weeks were to prepare for it. I'll be getting back to it soon. I need to get the veneers done properly in the next couple of weeks before it gets too cold. I have some other stuff to get ready so I can laminate a keel for a different boat this winter in my basement. I need to cut the laminate layers for that too before it gets too cold and I don't feel like it. I don't have much spare time to do stuff so things go a little (lot) slow with me.
     
  12. laukejas
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    laukejas Senior Member

    rwatson, fiberglass and epoxy? I never heard of such thing used for bending. It sounds a bit counter-intuitive, for I thought it would only stiffen that surface. But I guess it prevents that surface from cracking while inside surface is being compressed.

    But how does it make bending itself any easier? I mean, it's not like epoxy makes wood softer...

    Would you prefer this method to steam bending?

    Steve, good luck with that! Just wanted to check if you're still going :) I'll write you a PM in couple of minutes.
     
  13. SukiSolo
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    SukiSolo Senior Member

    Personally, I'd prefer another layer in the lamination. The less stress in the build the more accurate the end shape - and easier to form too. It takes a bit longer but I get fed up with fighting stringers and inwhales/gunwhales etc that don't really want to bend quite enough. Better to saw up another 'layer' and glue that in place.

    It also helps when yo need to use a ply skin, as the stringers etc are pretty 'solid' when you need to put clamping pressure on and then they do not move. Especially when building to the last mm (ie Class rules) this is important.
     
  14. rwatson
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    rwatson Senior Member

    Yes, it seems strange. The trick is that the glass is ONLY on the outside. As you said, it prevents the grain breaking out of the outer bend, while allowing the inner fibres to compress

    Extra laminations only work if the IF the timber will bend without breaking. That is the problem that Lewis encountered.

    You can make finer and finer laminations, until you are laminating really thin sections to build up a decent thickness, but all this is extra glue, planing, clamping etc etc.


    It doesn't make the bending any easier, but it allows you to bend without snapping.

    Steam bending is a fine process, if you have timber of good enough quality and size - but its all extra work.

    I used the technique when bending poor quality exterior ply for a skate ramp. Try putting a sheet of plywood in a steamer.

    The other time I used it was when I was using thin wood about 4mm - too thin to laminate. But it would not take a severe bend
    http://greencanoe.weebly.com/more-inside-stories.html

    By glassing the outer bend, i could pull it into the curve with no problem.



    I mention this technique specifically, as I know quality wood may be hard for you to obtain, and this may get you out of trouble on some occasions.
     

  15. lewisboats
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    lewisboats Obsessed Member

    The Cedar I used bent fine with a 48+ hour soak, no problems. With another 24+ hours drying time in position it kept about 80% of the bend when released and went back with no problems either. I used 3 lams to do the gunnel, 2 x 1/2" thick and 1x 1" thick, all 3/4" wide. The 1 x 3/4" stringers went in with no wetting or steaming just fine, but they were screwed to the frames and stem. I started at the stem then used the length as a lever to bend around the frames and clamped at the last one, glued and screwed in place on each frame after bending.
     
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