I was lucky enough to work as an apprentice for a well-established and successful marine canvas
shop last year. I made our dodger while I worked there - with the guidance from a really talented guy. (Thanks, Josh!)
You can see pictures of the process on our FB page SV Shameless. Go to Photos, then Albums, then Canvas Work.
Here's what I learned:
The first mistake was using the old canvas as a pattern. Canvas stretches (not uniformly) and changes shape once it is installed. Since Sunbrella canvas is actually plastic (polyester), it reacts to the sun and stiffens once stretched in place. In other words, it's not the same size or shape when taken off as it was when it was installed.
If you made a new pattern from "pattern plastic" (it has non-stretch ribs in it) and then disassembled the new dodger made from the old dodger canvas, and compared the pieces, you would see a significant difference, which would be enough to make the new dodger not fit right.
Dodger frames and boats are never symmetrical. After making the pattern and cutting out the canvas, I was surprised that the edges of the two halves to the piece never matched when I folded the piece in half. "Pattern's never lie," was drilled into my head
. Stainless tubing is never bent at the precise same angle, or cut at the exact same length. A small difference changes the angle over the course of a run of tubing.
When making the pattern, apply sticky double-sided tape to all the bows. Pull the bows as close together as possible (across the top - or whatever piece you are working on) as you stretch the plastic across it. It was easy to gain an inch (2.5 cm) or more by pulling to bows together. There is a lot of give in the connecting joints.
There are two parts
to the "securing" hardware
(snaps or pins) - the canvas side and the boat side. Install the canvas-side hardware
symmetrically (the same distance apart) to the canvas while it's in the shop, but WAIT to install the opposing boat-side hardware until the finished dodger is actually at the boat and on the frame. Start in the middle of the boat and work your way out to each side, one at a time, switching from side to side. It is very likely that the fasteners attached to the boat won't be in the same place on each side.
I was surprised how many hours it took to pattern, cut, sew, and install the dodger and windows. I was lucky that I had a huge, flat table to cut, move, and sew the canvas and windows on. I sewed our dinghy
chaps inside the sailboat while the dingy was on the dock
. I know for certain the dodger would not have turned out as nice if I had tried to cut out the canvas and sew it together on the boat. My Sailrite machine would have been able to do the job, but space is needed to spread the plastic and canvas out in order to do it right.
My advice: 1) hire an experienced, skilled (ie - not cheap) canvas worker to see if they can economically alter the existing dodger, 2) make a plastic pattern, take apart the new dodger to see if you can use any of the existing pieces and re-sew it, 3)or start completely over, 4) hire it done. Or, 5) become an intern!
After sailing our boat from Astoria, Oregon
to Cabo San Lucas, Mexico
, during an El Nino season, I now know why dodgers are so expensive. They're worth it.
Best of luck.