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Lapwing #20 aka Hirilondë


Hirilonde

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Another problem with the brass strip is that hitting a rock can not only bend the strip, but shear off or break the screws holding it on. And this could allow water to get through the screw hole into your board. (Yes, I know you would pre-drill the screw holes and saturate the holes with thinned epoxy or Gluvit. Or would you?)

 

After all of this discussion, on a small boat like the BRS, the double layer of glass (overlapped from both sides) will give plenty of protection unless you go looking for rocks to ram! You could add a couple more layers of glass if you want to. Less work that the rope.

 

But I really like the rope trick on bigger boats. Works well and about as bullet-proof as you're gonna get.

 

One thing I especially like about this forum is all of the different ideas from folks with lots of experience in a wide variety of conditions. usually there is not a right or wrong, or perfect solution to anything. (Well actually, I think that MY way of doing things is ALWAYS the best!!! )  ;)

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Lennie has it right.  The rope soaks up the epoxy and the result is a tough leading edge that can suffer some abrasion without exposing the wood to water.

Exactly

 

Another problem with the brass strip is that hitting a rock can not only bend the strip, but shear off or break the screws holding it on. And this could allow water to get through the screw hole into your board. (Yes, I know you would pre-drill the screw holes and saturate the holes with thinned epoxy or Gluvit. Or would you?)

Yup.  With the saturated rope some distortion may occur, but the wood stays sealed.  Now I can finish the sailing season and pull the board in the winter if it warrants repair.

 

Shaped with block plane and draw knife

post-442-0-01413900-1420563398_thumb.jpg

Belt sanded, then random orbital

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Trailing edge

post-442-0-33224600-1420563422_thumb.jpg

1 coat epoxy

post-442-0-52913900-1420563434_thumb.jpg

detail of line

post-442-0-84623800-1420563447_thumb.jpg

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  • 2 weeks later...

Well, my boat shed arrived in a 300# box.  All I had to do (my favorite expression) was set it up.  When the boat is finished it will become the boat garage.  I want putting the boat away to  go something like this:

 

1. rinse boat

2. open bailer

3. open hatches

4. back into garage and close the door

 

post-442-0-74220300-1421785095_thumb.jpg

 

post-442-0-31227500-1421785157_thumb.jpg

 

A couple days later my plywood showed up.

 

post-442-0-42985700-1421785222_thumb.jpg

 

post-442-0-40360900-1421785232_thumb.jpg

 

It isn't very warm in there, but it is quite roomy.  I will be borrowing a space heater so I can scarf plywood and other epoxy work on the 16'X4' bench.   My shop is in the garage attached to my house right next door.  My equipment will stay there. 

 

Now it is cut out pieces and parts, assemble components in preparation for setting up for planking.  Unlike the butterfly boats, this one has a ton of stuff to do before it begins to look like a boat.

 

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In the summer, moisture from the ground will make it damp in there. Get yourself a heavy duty tarp, and make a floor. I had a pole barn that had an open floor and things would rust faster in it than out of it. I finally realized it was the high moisture content. I put a plastic floor and covered it with gravel. you could feel the difference immediately.

 

Take Care,

Steve

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Love the shed. Where'd you get it?

 

I bought it directly from  http://www.shelterlogic.com/ Today I tried heating it with a small propane construction type heater.  I think that will work fine on a mild day keeping the shed warm enough to cure epoxy for scarfing plywood.  I am trying to get some work done this winter so that I have a chance at launching this summer some time.

 

"Parts is parts"  I am working from both ends to set up for actual planking.

 

 

 

post-442-0-51972100-1422125121_thumb.jpgpost-442-0-61280800-1422125131_thumb.jpg

 

I put 2 coats of epoxy on the transom to protect it during construction.  OK, I also wanted a preview of how the Sapele plywood would look varnished.  The decks will be Sapele also.

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I still don't get that saturated polyester line thing. It is softer than the wood. Why wouldn't you use a brass strip like they use on canoes?

 

A simple experiment should convince anyone of the superiority of an epoxy soaked synthetic line to any other kind of protective leading edge for a foil or even a stem of a boat.  Try a short piece your self and then try damaging it with a hammer on a workbench.  Since the epoxy soaked line was my original idea, I have to speak up now and again.  It has protected the stem of racing boats that were damaged in collisions as well as both bows of Graham's 44' power cat.  The fact that the combination of the soft line and harder epoxy makes for a very tough combination is the real secret behind its success.  It does deform a bit on impact but absorbs the force and the shape is not permanently changed. 

 

Since quite a few people have used this technique on their boats, I would like to have a report if anyone has ever had a damaged leading edge from any reasonable source. 

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Tom,

That is the first time I have heard of using the rope on the stem of the boat.

 

I am re-doing my CS 17 'Lively' and am trying to make her better at the same time.  My stem is always getting messed up from the boat trailer.  I am thinking maybe i will put a rope in there. 

 

What size rope would you recommend for the stem?  Also, do you have any suggestions as to how best do it.  Router?

 

thanks,

 

dale

 

PS: Sorry Dave for interrupting your thread flow.

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Tom,

That is the first time I have heard of using the rope on the stem of the boat.

 

I am re-doing my CS 17 'Lively' and am trying to make her better at the same time.  My stem is always getting messed up from the boat trailer.  I am thinking maybe i will put a rope in there. 

 

What size rope would you recommend for the stem?  Also, do you have any suggestions as to how best do it.  Router?

 

thanks,

 

dale

 

PS: Sorry Dave for interrupting your thread flow.

Dale,

 

The size of the line depends on the job.  Make the size to fit the shape you want on the foil or stem.  I always just plane off a flat and size the line so that it continues the surface shape you want.  I soak the line, fix one end with a nail and stretch it in place.  Then slather on some thickened epoxy to fill gaps and place some plastic sheet over it.  Pull and tape or staple the plastic so that the edge comes close to the proper shape.  You can shape the surface with a flat board to close to what you want.  I used to clamp a couple pieces of thin ply over each side to help shape it.  Don't do that any more unless a fairly sharp leading edge is needed. It may need a little more filling after the plastic is removed along with a bit of shaping although you can forget about shaping the line itself as it is too tough for that.  The fiberglass sheathing goes on last.  Its easier to do than to explain.

 

I think some 3/8" or 5/16" line would be right for a CS CB.  I don't remember what Graham used on the 44' catamaran stems but it would be larger than that.  I used some 1/2" on teh leading edge of my Grand Slam 7.9M daggerboard.  That boat hit an old engine block in the creek at about 5kts which stopped us dead.  No damage from stopping 6,000 lbs.  The aft end of the trunk did suffer some damage though.  I also used 5/16" line on the bow of Windmills.  On paddle tips for a whitewater canoe, I used 3/16" as protection from rocks. 

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I found that the routed channel worked really well.  I set up my router table with a fence and featherboard and did the routing before doing any shaping except the silhouette.  There is an added risk with this method, routers remove material really fast and don't care if it is the right wood or not being removed.  It (the channel)  kept the line round while stretching it out in place.  I didn't need any filling to get the shape.  It did take a second coat of epoxy to smooth out the line, but I was adding 3 coats to the board anyway.  I didn't go for a foil, I just used Graham's diagram for a leading and trailing edge with about  40% of the board still flat.  So half the line makes for a round leading edge that feathers into a taper.  I am waiting to make a longer list to save on shipping, but will order the graphite powder from Distributors  to add to the 2nd and 3rd coats.

 

Dale, I don't mind this "interuption" at all.  If a topic takes on a life of its own, but stays with boats and people are finding it interesting and/or helpful, then it can go where it will.  If I wanted a strict documentation of my build I would start a blog.

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Dave,

 

Many, maybe most, of the edges I've either done or advised about have been on foils that have already been in use.  Routing a groove would make for an added complication.  Sometimes a rat tailed file has been used on the bottom rounded edge to help hold the line in place.  Otherwise the flat edge has not caused any problem at all.  I'm glad that my desire to build a lapstrake boat has resulted in a nice addition to Graham's design list as well as some beautiful boats by other builders.

 

I made a stainless edge for the stem of Bluejacket LIZ.  After 15 years and a couple dings from various sources, I'm certain that a large epoxy line would have been much stronger and required less maintenance although the shiny stainless is pretty.

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HI All,

 

I'm just starting a CS 15 build and I've been gaining a lot from these discussions.  

 

In the plans, Graham specifies a brass strip to protect the keel.  What would you think about substituting the rope trick for the brass strip on the keel?    Two things come to mind:  I'd guess the keel suffers abrasion more than impact, and the brass strip might be easier to replace.

 

Bob

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