Re: [bolger] worse day of boatbuilding, top this one!

>> I always used 2x6 lumber for the strongback rails. These tend to be
>> flexible in the vertical dimension even when on edge, and I would
>just
>> wedge them wherever necessary to level them. This time however, I
>used
>> 2x10s, hoping to avoid the flex problems. It worked for a while,
>but as
>> the rails dried, one of them warped and I now have a 1/4 inch arch
>in
>> the starboard side. All the frames have been erected and trued. And
>even
>> with me standing on the starboard rail of the strongback, only
>about 1/8
>> inch of the warp disappears (I weight 180#!). That 2x10 lumber
>really
>> resists the flex I so feared. So I now I will probably have to
>remove
>> all of the molds, re-level the rail, re-install and re-true all of
>the
>> molds, and hope that the rail is done warping. With 11 molds, it's
>> probably a day, maybe a day and half of work. Ouch!

What floor material is underneath the rail? Can you embed some concrete, if
it is not already there, and use a screw tensioner to pull down to that?

There is clearly a lesson to be learned by some. Use kiln dried timber for
the strongback. What about a concrete block strongback with 100 x 50 (4 x
2) on the top?