Wednesday, February 10, 2010

Marking Out

I have now marked out all six sheets of ply, ready for cutting. I must say that I did underestimate the time this task would take, but I also think this was due to me double checking myself all throughout. I suppose this double checking has saved me time in the long though, because a couple of times I caught myself out and had to rub out inaccurate markings! It’s not worth thinking about the consequences of those errors either, as I can’t just run down to the timber yard and buy more ply, seeing as I live in the Hunter Valley in NSW and the ply came from France via Tasmania!

Something I really did not expect was the subtle curve in the sides of bulkheads 1 & 2. I thought all the bulkheads/frames where straight!

The other thing that had me somewhat perplexed when marking out was the slight negative camber that suddenly appeared in the sheer line toward the bow. When I saw the fairing stick with a convex shape all the way from the transom to the front bulkhead suddenly becoming slightly concave, it just screamed out ERROR!!! I was rechecking and rechecking all my markings and was becoming quite concerned about my measuring skills until the penny dropped. As it turns out, this is what gives rise to the cute upturned nose of the Goat.

I have a new appreciation of the skills of these boat designers now….:)

Tips for marking out:

OK, I’m certainly no expert at this, but I learned a few things along the way that might help others.

  • The first is that you really do need a longish straight edge so that you can draw your reference lines across your ply sheets. Mine is only a metre long which isn’t really long enough (get you mind out of the gutter, I’m talking about a straight edge!). I happened to have some 3 metre long steel square section (35mm) that was just perfect. As long as it’s dead straight for drawing long accurate lines, that’s all you need. Here you see the steel bar straight edge. Note also I’ve taped two sheets of ply together so I can measure and mark out the full length of the sides and bottom.


  • I bought a 5m long PVC molding that I thought would make a good fairing stick for marking the curves. The fairing stick is bent around panel pins at the reference points to produce even curves between them. This PVC stuff proved to be too floppy and when I sighted down the lines I marked with it, there were definite kinks where the pins were. You definitely need something with a bit of spring in it to produce a nice fair curve. Fortunately I found that a piece of 19x19 Paulownia which will be used for the for the seat cleats and other light framing was ideal. You might have a piece of some other wood (The plans specify Western Red Cedar but as long as the stuff you have is free of knots, you will likely find your stock will have a piece that is suitable for drawing fair curves)


  • When marking out the bottom, you have to draw another cut line 20mm outside the true chine line marks. If you’re using the 19x19 material, you just need to draw another line on the outside edge of your fairing stick. Done!


See you next time when I cut out all the parts….


  1. Excellent! Another tip... cut outside that 20mm "extra" line to give yourself a little more leeway when fitting the bottom.

  2. Marking is the basic and foremost task to be done for ply and exact measurement is needed to cut it to make wooden Furniture. This guy is the skillful person with creative ideas. Ply is a precious and the most expensive wood made for excellent furniture.

  3. You're all set on the wierd curve in the bow. I saw the same thing... AFTER I cut it and almost had a heart attack. CompassProject has a great suggestion, to "blow up" the plans and do a pirate squint looking down the paper lengthwise as opposed to from above, you can see that curve!

  4. There is also a more subtle reverse curve toward the transom as well that is noticeable when you squint along the line from the transom end. Even though I printed out my plans on A3, it's not that obvious, unless as you suggest you squint down the paper or lay a ruler along the line!