> 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.

Hey Mike, the pipe/cable strongback idea sounds like it has a lot of potential.

A couple of thoughts for discussion...

- The form registration is done by the pipe/cable/cable hole fit, right? How about gluing "alignment disks" (snug fit into the pipe) on either side of the form for registration? A bolt or dowel, through the pipe into the alignment disk, could be used as a "keyway" to control form rotation.

- Some care would need to be taken cutting the pipes. Ideally the pipes would be machined so that cut surface would be perpendicular to the pipe and the forms would stack parallel to each other. Cutting the pipe on a bandsaw or with a miter box should be accurate enough to keep the forms reasonably square. Cutting by hand and filing square might be a problem - I know that I would end up with spacers all different lengths and a wonky alignment ;-)

- The larger the diameter the pipe (providing it fits the form) the better and all the pipes need not be the same diameter. I have scrounged all kinds of 6" pipe from construction sites, 12" cutoffs are easy to find - just make sure you ask permission from the site foreman first! Note: If you are suitably dressed to be on a construction site - wearing safety boots and work gloves you are much more likely to be granted permission to search the bins for cutoffs.

- An alternative to using one spacer may be to position two (or two pairs) of smaller diameter pipes as far apart on the forms as possible and still keep a straight "line of compression".

- A pair cables could run outside of the spacers (close to the center of the forms). For best tension the cable should run straight without looping. Two individual cables attached to the bow and stern forms fitted with a large turnbuckle would be able to supply the tension. That plastic coated clothes line should be strong enough as cable though the tension would have to be checked once in a while to see if it stretches at all.

I wasn't going to start working on my Guillemot until the spring (my workshop is not long enough to build a kayak in) but I can sure get the forms and a pipe hardback ready before then.

Keep those ideas coming!

Hank