Spiling and planking

[RSudama]

I'm in the process of building an Ian Oughtred Puffin (10' dinghy) that requires spiling and laying lapstrake planks. I've built many boats before but never this particular technique. I've built the frames and attached battens on one side to take the measurements for the planks. I have a simple question: is it customary or even useful to put battens and take measurements on both sides of the boat? Reason tells me that the boat should be as symmetrical as possible, and therefore the planks and plank spacing should be uniform on both sides. It seems a good way to achieve this is to only put battens and take measurements on one side, and use those planks as patterns for the other side of the boat. Does this make sense, or am I missing something?

 

[gonzo]

That is common to cut the planks for both side equal. On a lapstrake, a small difference can be corrected on the overlap of the planks. In general, the top plank has more curve for looks, but is a personal preference.

 

[wet feet]

You have understood the basic idea correctly.It may be superfluous to mention it but do plank the two sides at the same rate,which is to say that having cut a pair of planks,fit one to each side before moving on to the next plank.I have heard of builders completing the planking on one side and then starting on the other side.Which may seem reasonable,and may work in theory,but if the moulds are not adequately braced and some movement has occurred,there can be a lack of symmetry.

 

[jehardiman]

Welcome to the Forums.

I have a simple question: is it customary or even useful to put battens and take measurements on both sides of the boat?

Generally you only need to line off one side, but a lot of that depends on what material is available. There are known lapstrake vessels from wrecks and surviving examples with a different number of planks on each side. To do this you you need to line off both sides. For a 10' dinghy the planks are smallish...so you don't need 40+ foot long 30+ inch wide planks which could be hard to find even hundreds of years ago. One of the reasons the stem and stern posts on large nordic vessels were carved.

Reason tells me that the boat should be as symmetrical as possible, and therefore the planks and plank spacing should be uniform on both sides. It seems a good way to achieve this is to only put battens and take measurements on one side, and use those planks as patterns for the other side of the boat. Does this make sense, or am I missing something?

That is the typical method for small vessels, and wet feed said, with both planks being cut at the same time because they are not that thick. Again, it was a little different when you had big thick stock and had to hew the line by hand.