Lapwing #4

[John Turpin]

Took a leap of faith today (with some tuition from Graham and some reading) and cut my first strakes today.

Excellent news! I'm a few weeks behind you now. However, I've got to wait on Graham to finish the strake design/patterns. There is no way that I'm going to try to figure this out myself.

Please, keep taking photos for us.  Great work.

[Richard Whitney CS#70]

John - I am going to go as far as the first two (there is a drawing for No. 2) and then see how confident I am feeling.

[John Turpin]

Richard,

In the set of CD photos, it looks like Graham had a temporary form in place between the foreward and mid bulkheads when he started his planking (see below).  Are you doing this as well?

[Richard Whitney CS#70]

Hi John

Graham put that in on one side to try it out and worked out he did not need it - the stem, forward bulkhead, mid bulkhead, rear bulkhead and transom give the 'contact points' necessary to give the right panel shape.

[John Turpin]

Okay, that makes sense.  So, when you cut your garboards, did you just strike a line that connected the five contact points?  Could it possibly be that easy?

[Richard Whitney CS#70]

Nearly that easy.  I worked out the maximum width and cut two boards that width and scarfed them so there was a straight edge to sit along the keel line.  I then measure along the keel line the distance from the transom to  each bulk head and marked that point on the stock and draw a 90 degree line at that point across the board.  Then went back to the boat and measure the distance from the keel line to the 'notch' for each bulkhead, transom - marked these on the stock, put a small nail in each point and used a long batten to lay a curve.  Then cut both bits out leaving a bit extra at the stem end because I was not sure how to get the shape there.

[John Turpin]

Brilliant.  I think I'll do the same thing.  But, I've got some tasks (including stem shaping) to do first.

[Richard Whitney CS#70]

First two strakes laid this weekend.  The good thing about doing these two first is that they are on the bottom of the boat - a good place for the learning curve to happen before getting to the bit you want to look really 'fair'.  The twist at the stem is tricky with these two.  A few mistakes made - but with a bit of filler and paint it will be fine.

Nice to have the hull 'locked together' now.

[John Turpin]

It looks great, Richard. I plan to get to that point within the next two weeks.

Can you describe the struggles you had at the stem?

[Tom Lathrop]

Looking good Richard.  Time spent cleaning joints inside the boat is time well spent.  Repeat that a few times.  The first mark of a nice lapstrake build is how the strakes meet the bow and how fair the gains are. 

[Richard Whitney CS#70]

I am being extra careful on my shapes and the gains moving onto the next lot of strakes.  I have also been doing some 'spiling' practice.  I have now got two battens made of of cut offs from ply that has already been scarfed.  Each batten is about 2 1/2 - 3 inches wide.

Here are some shot if me practicing getting dimensions at the bulkheads for strake 7.

First shot show spiling batten laid across forward bulkhead and stem.

[Richard Whitney CS#70]

Finally got up the nerve to cut out stake 3 - fits well.  I just need to plane the land and cut the gain to be ready to glue them on.  The spiling stick method worked well enough to give me confidence to move onto the next one.

[John Turpin]

Your #3 fits much better than mine. I should have stopped and recut, but I forged ahead.  I've learned a lot since then.  That ill-fitting board created much work for me. Subsequent boards have fixed the problem, but now, a plank has to be perfect before it goes on.

Your boat looks great.  Well done!

[Richard Whitney CS#70]

I have completed strake 3 (John T and his boys are pulling away from me like a Southern Skimmer on a broad reach).

Good to do the learning on the strakes that will be under the boat.  Now I am 'turning the corner' I will need to be tidier on my glueing etc.  So far the 'spiling stick' method where I am pulling off the measurements for the strake shapes base on a measurement at the transom, rear, mid and forward bulkheads and the stem seems to be working out well.

On to No. 4 (half way is in sight)

[John Turpin]

Outstanding! It's looking like a boat now!

[Lance Turner]

Richard,

I built a lapstrake canoe called Charlotte, designed by Tom Hill.  Tom Hill's method uses ribbands to define the shape of the strakes.  In Tom Hill's method, you mark the shape of the next strake prior to glueing the previous one.  This is how you go about it using Tom's method.  However, when doing it like you are doing, I would say be careful not spile out a strake any further ahead than the next one to be hung unless you insert a small piece of the planking thickness at each station mold to represent the not-yet-hung strake prior to the one your are spiling. (Tom Hills method) It doesn't sound like that small thickness will make a difference but it will.  What will happen is the strake will not fit properly and will have to "edge set" or forced into position once it comes time for that one to be fitted on the form.  Of course if you cut the strake oversize then you will probably be ok. When I built Charlotte, I had very little waste by not cutting the strakes ovesize.

[Richard Whitney CS#70]

Thanks Lance

I am doing the measurements one at a time.  I am also overlapping the batten I am using on the previous strake about the middle of the boat to help get the 'curve' as accurate as possible.  So far other then the tight twist on strake one I have not had to force anything into position too much.

[Richard Whitney CS#70]

Help - looking for some suggestions.

I have cut two mirror image strakes for strake 4.  One fits well - the other doesn't.  Looks like for some reason I am getting some small differences setting in one either side of the boat.  On one side I have to twist and get what I think people are referring to as 'edge set'- on that one side (not the one I took measurements off) I have to bend the stem side of the strake up a bit to get it to fit.  This shift the strake at the mid section so it has 1 1/4 inch overlap on strake 3 rather then 3/4 in.

Should I just make strakes a different shape on each side - or will this just be compounding the problem.  Any suggestions appreciated.

[Tom Lathrop]

It's difficult to know what went wrong.  Obviously the symmetry got lost a bit.  The first thing to check is whether the form got twisted a bit to one side.  I always have a centerline string to reference this to make sure that the boat stays symmetrical.  Of course, it helps to always have this string from the beginning to know if it moved or not at every stage of construction.  It's a common problem.

I'd check this first.

[Richard Whitney CS#70]

Thanks Tom

I am going back on checking everything on strake 4 measurement.  Looking at what I have cut out - both don't quite fit - so the difference may not be as big as I thought.  String line still looks pretty good.

I have remeasured and think I have figured out what I have done wrong.  I had my spiling batten sitting flush on each bulkhead allowing it to form a natural curve.  Doing this does not allow for the 'extra' shape that results from one edge of the new stake needing to be defined by the existing curve of the previous one it will be attached to.  When I allow my spiling batten to lay along the 3/4 in overlap on the previous strake and pull the measurements off that way I get a different result that I think will be closer to what it should be.  I will look carefully before wasting more wood.

Would I be best to make each strake to fit the side they are on - even if they are a little different in shape?