Mystic River Strongback

Seemed simple enough... first step glue and nail the strongback together for the Mystic River canoe. I purchases a kit, which comes with 1/2" plywood.  Plywood was warped but I figured it would come together straight. It is definitely not straight/level.  I built it on my concrete garage floor.  Not sure what to do now.  Should I even attempt to build the canoe on the strongback.  Any thoughts on how I should proceed?

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RE: Mystic River Strongback

I assume that you purchased the CLC strongback?  You say that the ply was warped, in which direction?.  Some twist in the ply sections should be fine as long as the ply is straight in the long dimension. 

I have built about four of those strongbacks without issue.  I will note that I had a slight bend in the end of the first one when I used my garage floor to build it.  I did not realize at the floor was not perfectly flat and sloped down a bit near the door.  Since then, I have used a perfectly flat 8' table as the building surface with saw horses to support the completed overghang.  The other note is to make sure that you exactly follow the directions regarding order of construction so that no two seems are colocated.

I recognize that with you strongback completed, the above info is of no help.  First, where is the twist/bend located?  The Mystic River is only 17' long so you will be cutting +3' off the strongback.  If the problem is on one end, then cut that end off (that is how I fixed my problem).  Once that is done, how bad is it?  It is possible that you can fix the problem by just shimming a couple of the forms.  As long as the forms are all aligned, the boat will be straight and true. 

If the problem is bad enough that shimming a couple of forms won's fix it, I would not risk using that strongback.  Contact CLC and see what they will do for you.


RE: Mystic River Strongback

ditto marks points.

if it is not straight enough that the play between the forms and he strongback, can correct for it.  you need to pause.

i have had to make minor adjustments that worked in a strong back.

one is, if you have really heavy sawhorses, you can lock the strongback to the sawhorses and twist it into shape using the torque exerted by the sawhorses (with shims under the legs of the sawhorses.

the second way i have addressed this was    

RE: Mystic River Strongback stepped on send button.

the second way i have addressed this was using a wire attached to two screws on the strong back off to the side....and pulled the piece back into alignment.  this second approach was very rube goldberish.....but worked.  i had to drill little holes in the forms for the wire to go through...i was please with my cleverness....but it was a real hassle.  

the first approach is the more common one i use for realtively minor twists....


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