Rear Side Panels

I've just cut up a perfectly good sheet of 12mm Marine Ply! The stingy, frugal side of me was very nervous about stuffing up the measurements for the Rear Side Panels. Both are made from the same sheet & they come within millimetres of one another so a misjudgement could lead to tossing away $120 bit of firewood. 

But it went okay thanks to some useful advice in the Paradox Builder's Guide. The advice, to mark both sides of the sheet while marking out, was aimed at having reference points on both sides of the sheet in order to make assembly easier. I found that marking both sides of the sheet acted as a blind test that the marking out was correct. Once the marks on each side of the sheet were cross checked, I felt a whole lot more comfortable attacking the cuts with a sabre saw. 

The only advice I would offer with marking out is to take your time; mark off twice & cut once was too cautious for my liking. I marked out & double checked twice over! Another tip when marking off curves is to put tacks into each strategic point on the curve to hold your batten against. This gives a nice fat curve, just make sure you pencil in on the same side as the tacks... 

Look, there are some tricky measurements on the Sides that you need to mull over before marking out. Basically. Apart from the scarf edge & the a Transom edge, both sides end up curved. Use the edge of the sheet as a reference to mark your Datum, I did my datum 28mm in from the edge, The Book suggests 50mm but I couldn't follow that reasoning. In metric countries, like Australia, the plywood sheets are actually smaller than in Imperial Countries, so a 50mm datum may produce only firewood. Don't rush it!

"The Book" also advises to cut 3mm outside each mark. This is excellent advice which I took & was glad I did. Back a few years before sabre saws boatbuilders used jigsaws, a lightweight version with blade width a maximum of 6mm. These skinny blades would wander to over 20mm offline on the underside of the cut if the blade was dull, the wood grainy & tough or thicker than usual. Of all my boatbuilding tools I had the least  confidence with the jigsaw. Nowadays, the sabre saw is way better, but it can still roam so give yourself a fighting chance, take 3mm less first up. 

Okay sides cut, I clamped them together for sanding. This saved time, but ensured I had to of the same Sides, the idea of having an asymmetrical sailing boat freaks me out. Imagine having to hold the tiller to port all the time? Okay if you want to circumnavigate islands by the right all the time I suppose. 

 TWO REAR SIDES BEING SANDED AS ONE