Jump to content

Lapwing 16 Build


Murray

Recommended Posts

Well After quite some time without anywhere to build, we have moved into our new house overlooking Lake Karapiro in New Zealand. It's a man made lake used for hydro power generation , there's just a bit of the power company's domain between its and the water. I see the lake from the window in the garage at the back of the house where I will start. Having looked at the plans for some time, I find it's like a map of a foreign city; until you get there, none of it makes any sense. Regretfully, this, combined with a short attention span and an unwillingness to read carefully, inevitably rework is occasionally necessary. 

 

I decided to jump in at the deep end of the project - literally, and start with the Centreboard. Attempting to replicate 1/4 sawn stock - some very nice Alaskan Cedar - available in 6M lengths, made the start of the project very enjoyable. Next job - the rudder...

IMG_4566.jpeg

Link to comment
Share on other sites


Woot, another Lapwing!

 

I love Alaskan Yellow Cedar. It shapes and works like a dream. I will suggest however that you glass the centerboard.  The plans don't call for it, but they assume a hardwood glue up. Unless you have built the trunk/case, the thiickness doesn't matter yet. Hopefully Graham will notice and comment.

 

Post a lot.  It is good therapy, especially as you are spiling and cutting/fitting planks.

Link to comment
Share on other sites

Next the rudder and the rudder stock. I had plenty of ply so I used that for both parts; not so pretty, but it will all be painted so it won't be seen. I covered the blade in layered glass then graphite top coats - a bit of sanding to remove the layers, but getting there... 

 

Thanks for the tip Dave - in the photo of the centreboard - it's difficult to see but there are two layers of 6oz glass covering it. The lake here is deep so I didn't bother with an epoxy soaked rope at the leading edge. I may live to regret that should I sail elsewhere!

IMG_4728.jpeg

IMG_4801.jpeg

IMG_4802.jpeg

Link to comment
Share on other sites

Next I started cutting out frames and longitudinal bulkheads, making the transom etc. It was about here that I missed the text which noted to bevel the aft edge of the transom seat shelf. When first dry fitting the transom to the Longitudinal bulkheads, the mistake was immediately obvious. You learn from your mistakes right? Well at least, we try not to make the same mistake a second time. So I cut the seat shelf off without too much trouble, cut a new one and tried it in place. I forgot to take a photo of it before I started to assemble the frames, but it's a good fit now. 

 

IMG_5039.jpeg

IMG_5159.jpeg

Link to comment
Share on other sites

Dry fitting the frames and the longitudinal bulkheads showed the advantage in having the two sawhorses level, it all seemed to go together quite well. I figured that if I cut the frames out carefully, made sure the longitudinal bulkheads were close to identical, and made the aft frames square on their marks, that by the time I got up to the front bulkhead, the angle between that and the two longitudinal bulkheads would be pretty close to the same on both sides.  0.2 degrees  difference seemed close enough that you'd never see it looking at the boat.

 

I found there is a surprising amount of 'movement' in plywood - cutting a frame to allow it to go over the longitudinal bulkhead allowed the free ends to wander about quite a lot - relative to each other.

 

 

IMG_5163.jpeg

IMG_5164.jpeg

Link to comment
Share on other sites

Take your time on the frame.  This isn't a fold open boat where the pieces make the shape come out.  Everything else from here out is shaped by the frame. Yes, level your saw horses.  I even clamped my frame to them so there would be no movement during the build.

 

Comparing a port side piece, frame, strake, what ever, to the starboard piece is always a good idea. Graham gives you the garboard, but you get to spile the rest, and matching them is important.

 

Link to comment
Share on other sites

Thanks for the advice Dave - much appreciated. I thought it useful to check the stem was plumb - since the saw horses were level, and the Longitudinal bulkheads were identical, likely the transom was level, so I set up a string line from the centre of the transom to the stem. A little parallax error in the photo, but it was on the string.

IMG_5185.jpeg

Time for some planks...

IMG_5177.jpeg

IMG_5200.jpeg

Link to comment
Share on other sites

Good to see the planks fall pretty cleanly on the longitudinal bulkheads....

 

...then on to the dark art of spiling. Took me a while to understand that you need to have the planks fall in the correct lie without too much tension anywhere. Any tension will see humps and hollows in the line of the lap... yes you can sand and fill them to bring them back closer into line, but better to get the fit right in the first place. I found a photo of Blue Peter Lapwing build - seems there website has gone, but the spiling truss shown in one very low res pic set me off on the right path....

 

 

IMG_5221.jpeg

IMG_5332.thumb.jpeg.9eb026f6ba7435bef0e8127c8dc5fa14.jpeg

Link to comment
Share on other sites

...to get nice 'clean' gains, I made a simple jig for my router to sit in. Works pretty well...

 

I found a site 'Off Centre Harbor' which has many helpful videos. But a series I found really useful was on using Epoxy.  lots of really useful tips from a master of the art.

 

IMG_5373.jpeg

IMG_5375.jpeg

Link to comment
Share on other sites

You're cruising.

 

I made u shaped clamps out of plywood and shims to tighten them for the planking laps.  Your screw/pad idea seems to work well also.

 

Snazzy router sled for making the gain rabbits.  I did mine by hand with a rabbit plane. This detail is so important. getting each plank lap to go flush for the last inch or so looks so cool later when all are done. I used a block plane for the varying bevel on the plank being lapped.  This detail is important to keep the lap thickness consistent.

 

After each pair of planks make sure to step back and view the boat from all angles.  It is easy to get something unfair when you are on top of the work.

 

String, plumb bob, levels, you can't check details like the stem too often. You seem quite on top of this.

 

I finished my Lapwing over 5 years ago and this is the next one to document here.  Bringing back memories of the build.

  • Like 1
Link to comment
Share on other sites

Dave I think your plywood clamps with wide shims probably spread the load a little better than my screws and pads. I've changed my method a little, so the screws are now inserted into the edge of the new plank. I think having them bridged put too much pressure on the outside of the plank, past where it was supported by the bevelled edge, causing slight dimples which needed fixing. 

 

If you're getting withdrawal symptoms from see a new build - fell free to pop over and give me a hand...! 

 

Sorry about the pic - for some reason they keep getting rotated as I load them.

IMG_5410.jpeg

Link to comment
Share on other sites

  • 7 months later...

Temporarily right way up; I wanted to put the inwhales on to stiffen the sides before I spent too much time fairing the hull. I was using a single piece of 38mm x 19mm Yellow Cedar. It's beautiful timber to work with, but quite strong so bending it it to dry fit it was quite an effort. I was also somewhat resistant to the twist from coming to the stem to to the reverse twist at the transom. However they're in now and it makes the boat a lot more complete looking. i guess i'm quite critical of my work - I see every error, but when I look at other boats, it's easier to see that others have issues too. Interestingly the set-up must have been OK, the boat measures within a millimetre stem to each corner of the transom. Biggest challenge was spiling. I used a truss of two battens joined by hot glued ply, but it wasn't that accurate. forcing planks in I learned a new skill; how to make a really bad edge set...! next time I think I'll use a compass and see how it goes. One thing for sure is, if you don't make a correction to the bad plank before you lay another on top, you compound the errors. Guilty!

IMG_6840.jpeg

Link to comment
Share on other sites

Alaskan cedar really is a lovely timber...

IMG_6846.jpeg

 

Easy to see in this shot that when I bevelled the stem, I went too far. Better to have put the bevel in as the planking started, rather than using the convenience of a workbench to work on, and putting the bevel in before attaching it to the boat. I know, obvious now, but it wasn't at the time.

Edited by Murray
Link to comment
Share on other sites

Nice work. It looks MUCH more challenging than my CS15... (of course, that’s a reason I chose it.)

My son is considering building a lapwing (Phoenix 3).  I think he has the patience and detail-focus likely needed. ? I passed along this blog to him. 

Link to comment
Share on other sites

AYC is beautiful wood.  It shape well also. It is almost as nice for oars and spars as Sitka. My Lapwing oars are AYC. Flipping a Lapwing, especially at this point is so easy. No reason not to do so and put in the inwales.

 

The Lapwing is one boat where the hull is a lot of the work.  You are further along than it seems.

Link to comment
Share on other sites

10 hours ago, Hirilonde said:

AYC is beautiful wood.  It shape well also. It is almost as nice for oars and spars as Sitka. My Lapwing oars are AYC. Flipping a Lapwing, especially at this point is so easy. No reason not to do so and put in the inwales.

 

The Lapwing is one boat where the hull is a lot of the work.  You are further along than it seems.

I was wondering that very point Dave, I might be making good progress after all. On one hand that's great news. On the other hand....

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.