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Fishman38

fishman38 OK20

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Round over end to end.  When you glass the inside, the glass won't lay on a 90 degree corner correctly.  With the round over and the fillet the glass will lay right without any air gaps.  If you do it right.  Also where the stringers are visible the round over is more pleasant to look at and sharp corners are prone to breaking when struck by something.  In my Penobscott 14 build, all the stringers are visible.  Also they are walked on and bumped and banged.  They are round over except where they contact the frames.  Here they are left square to bite nicely in a square notch, which also helps keep the twist in the stringer and looks cool to.

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Fishman 38,  If you can I would get Greg Rossel"s book BUILDING SMALL BOATS.  An excellent read with lots of valuable info.  A must have book.

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However it does seem that this would cause some degree of weakening unless one fills the void created between planks and stringers/chines with fillet (which seems in fact might strengthen the joint not weaken it)

 

 

On second reading, this sentence doesn't make any sense in the present context, so am deleting it.

 

Thanks for the tip Miyot.  I'll track down a copy of the book.

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post-2179-0-40640000-1368155739_thumb.jpg

 

post-2179-0-38049000-1368155769_thumb.jpg Cut off at the knees.

 

post-2179-0-00455000-1368155798_thumb.jpg 

 

post-2179-0-24021800-1368155825_thumb.jpg  I was concerned that "several hundred" pounds (per Gougeon) on the baseline would distort the strongback. This is one of a couple of steps to avoid that.

 

post-2179-0-81194500-1368155882_thumb.jpg

 

post-2179-0-16786900-1368155854_thumb.jpgFinally, the beginning of a boat.

 

 

 

post-2179-0-85094300-1368155911_thumb.jpg

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post-2179-0-63216300-1368624054_thumb.jpg

 

When I inserted the keel in the frame notches, I notice I have a bit of a "dogleg" in about the aft 10 feet.  I think it must be straightened before gluing it to the frames.  Best method I can come up with is to, with it held straight with clamps, glue a strip of (3/8 or 1/4)  plywood to the flat top side over the full length of the bend.  I could either cut away enough of the keel to make room for the ply or deepen the notches in the frames.  Any suggestion are welcome.

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I think this is one of those cases where only you will know it's there, but knowing it's there will drive you nuts.

Just to offer a different choice, you might fit a 2x6 (temporarily) along the starboard stringer/bulkhead and wedge in lengths of 1x2 from the 2x6 to the keel to push it into place. Then plank the port side first.

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Thanks Gordy.  You're right it is the sort of thing that would drive me nuts just knowing it was there.  Since I posted about this, I've done further investigating and find that it isn't going to take as much force to correct the problem as I first thought, so maybe beefing up the frame supports (risers?) a little, plus some bracing such as you describe until the stringers etc and the first of the planking is stuck down is all that is needed. 

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By beefing up #6 & #7 frame supports I was able to take out most of the kink in the keel. I used Gordy's suggestion (pictured) to take out the rest while the keel/frame epoxy set.  Will probably set it up again when I mount the transom and when one sideof the bottom planking goes on.post-2179-0-34350800-1369189866_thumb.jpg

Took most of today to get the bottom stringers faired and glued.  Got a surprise when I gave one of the outboard stringers a swat with the palm of my hand to seat it firmly into place.  It broke at the narrow 4"(+/_) span above one of the slots.  I should have (more gently) tapped it directly above the slot.  Probably would have been ok.  Something to be more careful with.  I glued and clamped it into place and will add a gusset or two to strengthen it.  (Are there "gussets" in boat building?)

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post-2179-0-28747100-1369189925_thumb.jpg

 post-2179-0-00049200-1369189951_thumb.jpg

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Got the transom reinforced, hung on the keel and glued in place after a couple of weeks and a lot of head scratching.  That was the biggest puzzler I've encounterd so far on the build, mostly fretting over how much strength it was going to have as designed. After finally realizing how much epoxy will be holding it (keel, bottom stringers, engine well walls chines, planking  and side stringers) I'm satisfied.  One thing I did which didn't seem to be shown in the plans was to slot the top 3/8" layer of the motor board to accomodate the two inboard bottom stringers and epoxied them in.  So far am pleased with how it turned out.  Also got the chines glued and screwed in place today except at frame eight and the transom.  Will get those glued and screwed tomorrow and start adding gussets where needed.  All the screws will be removed after the epoxy is fully cured.

post-2179-0-99012700-1371182910_thumb.jpg

post-2179-0-92021200-1371182940_thumb.jpg Started out using regular 3/16 washers.  Much to small and dimpled the ply.  Got some 1/8x3/4 fender washers which work much better.

post-2179-0-98698300-1371182968_thumb.jpg Looked to me Graham was showing only one of the 3/8 plys notched for the keel.  Being one of those "if a little will do a little good, a lot should do a lot of good" guys, I notched all three for more glue surface.  Also measured only once and had to glue a half inch of filler to the keel.  See pics :angry:

post-2179-0-09472200-1371183024_thumb.jpg Slot for the inboard bottom stringer.

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post-2179-0-99762500-1371183078_thumb.jpg

 

 

post-2179-0-64406000-1371182996_thumb.jpg

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 Looked to me Graham was showing only one of the 3/8 plys notched for the keel.  Being one of those "if a little will do a little good, a lot should do a lot of good" guys, I notched all three for more glue surface. 

That philosophy is not necessarily sound in all applications. I won't even guess what is best in this application, but when in doubt I simply trust that Graham designs things as he does for a reason.  When I know more than him I will second guess his design details.

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Actually wasn't second guessing, just guessing.  It wasn't clear exactly (to me anyway) how he intended it to be so I opted for what seemed to be best.  The comment was tongue in cheek, so to speak. 

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Stainless steel vs Silicon bronze;  SS screws are readily available locally, silicon bronze not so much.  Is silicon bronze a better choice for general purpose marine fasteners?  If so why?  Does it matter whether the vessel will be used in salt or fresh water? 

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stainless steel is:  stronger, harder, corrodes easier

bronze is: softer, less strong, probably the most corrosion resistant material for fasteners that is practical

 

Salt speeds up corrosion, it is an electrolyte.

 

There is no universal answer to your question.  For below the water line, where the fastener will get wet (not encapsulated in epoxy) I think it is the best choice possible.  For classic plank on frame boats I would choose nothing but bronze.  For other uses my opinion is not so concrete.

 

I hope this answer doesn't just make your decisions harder.

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Thanks Dave, that does help. I think in my situation the extra toughness of SS wins out.   I don't expect any screws below the waterline except maybe one  transom to keel which will be encased in epoxy, and maybe some accessory mountings such as transducers.  I'll probably use SS there too, since most of my boating will be in fresh water and if that ever changes i.e. relocate to the coast, they can be easily exchanged for silicon bronze.  Any other exposure to salt water will be just for a few days and then a hose down with fresh water. 

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post-2179-0-85795100-1372387955_thumb.jpgA couple of my neighbors

post-2179-0-15293900-1372388000_thumb.jpgA closeup.

post-2179-0-73664100-1372388047_thumb.jpgCockpit framing.

post-2179-0-26217500-1372388106_thumb.jpgApparatus I used for checking the fairing of the bottom stringers.  Crude but seemed to work ok and I couldn't think of a better way.

post-2179-0-55986000-1372388150_thumb.jpgMaking some minor adjustments.  May not have been necessary but what the heck.  .............BTW a man just can't have too many clamps when he starts building a boat.

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This is a little off subject and a ways off for you but I have a little planking trick for you.  I found when putting on the outer layer of planking that sometimes my outer plank would not lay down all the way where it butts up to the last plank on the outer layer.  Small amounts of cured epoxy can block you next plank from laying down along the seam.    When the epoxy is curing some would weep out along where the next seam will be.  Even though I cleaned up well, some would inevitably seep out.  Now I would sand this joint before laying the next outer plank, but this is a lot of work and cured epoxy in the bottom of the seam is hard to sand at the bottom of the 90 corner.  What I did was take my little rebate plane and plane a small champher  along the inside lower edge of the next outer plank.  This only takes a minute, but lets the plank lay down fully so it is flush with the previous plank.  It also leaves a small channel for the epoxy to flow into and allows it to flow up or down this channel helping to fill any gap between the planks.  If you don't understand what I'm trying to explain now, you will get it during planking.

 

It works so well that I now automatically champher the edge with out even thinking about it.  

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I think I understand what you're saying and hopefully will remember when I finally get around to planking.  Thanks for the tip.

 

Dave, if you were doing it over would you plank the bottom before installing the side stringers again?  In other words did any problems show up that might have been avoided otherwise?  I'm thinking I'll do the same but reaching the bottom of the twenty footer is a little easier than the twenty four so if there's a downside i may want to re-think it.

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