About the time I initially was making the post about deck fittings, I jotted down some ideas for strongbacks but never went any farther with it. Mostly pretty boring but the most stupid idea was to not really use a strong back at all:

Take your forms and drill a 1/4" diam hole at 3 3/4" apart in exactly the same location on all of them. Take some 4" pvc pipe and cut (one less than the number of forms) a bunch of 11 1/2" lengths. Get a loop of about 16' long of 1/4" galv steel cable, climb up a 16 foot ladder with the two free ends of the cable and thread on a form, throw on a pc of pipe, thread on a form etc., etc.,etc. Clamp the two ends together. Tie one end of the loop to a tree and tie the other end to your car bumper. Put 'er in first and drop the clutch.

Now all your forms are perfectly aligned! Firmly drive in a wedge at one end and you've got a complete ass'y that is a composite strongback - the spacers and forms are the compression member and the cable is the tension. I've actually sorta done this in my setup in that the forms and spacers are being used in compression and become part of the strongback.

But another idea might be more useable. If any of you are window guys (gals), what about using a structural aluminum curtain wall box section? This section is like a box beam, but has a continuous female threaded track down the narrow side. They can come in many sizes ( say 2"+- X 3,4,5"+-). Cut off the threaded track from one section and attach it to the other side of the section you are using, and you could attach the forms anywhere you wanted. I think you can get slip couplers for these, so they could be any length that you wanted. ( 8 feet for me, and 15 feet for you). Easy to take apart, easy to store, variable lengths, variable spacings, dimensionally stable, - may work?

- mick