I know what you mean about curving wood. The new wood is thicker than the old wood. So, we can't make spacers based on the old deck. We could, however, take measurements of the new deck that has been laid down and that isn't warped. However, we are very much at the mercy of the people that drilled the bolt holes into the steel frame. Sometimes, in order to get a straight board, some of the bolt holes will be close to one edge of the board. Another trick that I use when lining up the wood is paying attention to the black paint lines on the metal from from where the previous board was.
When Roger and I lay the deck down, we correct for the warping by drilling holes on the ends and puting a bolt at each end. Then we push on it with a crow bar until it looks like it's parallel with the other boards. Then, we make the rest of the hole marks on the wood, drill them, and then bolt it back down. It's extra work, but we got a few boards to straigten out early on when we first started laying deck.
I was a little disappointed to see that one crooked board when I came back to work on the boat last month. I'm happy to say that I did not lay that board down. At the same time, I understand that there is a learning/experience curve with laying the deck down from making the right cuts to drilling the counter-sink holes to the right depth. If that board really bothers us, we can always pull it and put a new one in there.
Is the wood stacked near the shed warping? I'm guessing that randomly piling/throwing the wood on the bow and letting the sun and rain take their toll is causing the warping. We'll probably need to take more care in how was stack the wood in the future to minimize our installation work-load.
As for reenactors, Jay, Roger, and myself will be the only regulars that you see. Travis helps if he's in the area. John G. has been pitching in a lot, too. The last time that Tim K. was helping, he said that he knows guys that treat 'work' as a 4-letter word. They want to play, but they won't pitch in to help. I see this in reenacting a lot... even in past churches that I have attended. Sad.