Re: Old Stringers Are Out-is The Hull Twisted
Boats are often not symetrical. But a good method of determining hull straighness is to run a string down the center of the boat from bow to transom and pull tight. Then measurements can be taken from port and starboard sides to determine if the hull is bowing out. Measurements can be taken every foot vertically to determine if the keel has a proper gentle slope or curve or is wavy.
A string can also be run down the outside and bottom of the hull and check for dents or bulges. Have one person hold the string at the transom, you pull it tight and wrap it around the side of the hull towards the bow and look for gaps between the string and hull.
Don't be surprised if your boat is not symetrical, very few are. I know both my boats are not, but I would not have know it if I had not tried to find center and took measurements for top projects. The Bayliner is out if "symetrical" from bow to transom by as much as 3/4" in some places. Not too bad if you ask me.
The most important thing to check for is a "hook" in the bottom of the hull. This is like a big dent that will really have a big negative affect on the way the boat handles. When you eyeball the bottom (from transom to bow), it should be fairly straight, not wavy or twisted. If it is obviously crooked or twisted, then there is probably something wrong.
If you determine there is something wrong, you can brace the boat by placing furring strips from gunnel to gunnel to pull the sides back into aligment or put 3/8" rope around the boat in big loops, put a length of broom handle in the rope and start twisting to tighten the rope and squeeze the hull back into shape. If the boat appears to be twisted left or right when viewed from the transom, then blocks can be placed on the trailer to correct for the twist. Then install the stringers and floor and the boat should hold it's shape.
