More fun with Shock cord- Bimini Frame

Had been annoyed for awhile with the arrangement for securing the bimini fore and aft.

As you can see, Windstar has three pieces of canvas, the dodger, the bimini, and a connector spanning the two.   The conector can only be used in harbour, as the main sheet track is in the cockpit.   As it is, the main sheet fouls the dodger slightly when running.
It's a good setup for this boat however it requires slacking and re-tensioning  the lines securing the bimini fore and aft in order to attach the connector canvas.
A perfect use for shock cord!
After puzzling this out a bit I positioned two fixed-length lines led forward.  these define the limit of rearward tilt of the bimini frame in the absence of the connector.  Below, port side.

I then added shock cord to pull the frame aft against those two fixed lines, and further added two lines parallel to the shock cord that can be tensioned with a rolling hitch.

The shock cord provides enough tension to spring-load the bimini against the connector or the forward lines, and the adjustable parallel lines define a limit of forward travel.
Works great and the bimini can now be pulled forward to operate the connector zippers, and it springs back into place when released.

Working with shock cord

 The spinnaker pole rebuild triggered an investigation into shock cord.

Buy it.

It's not easy for the novice like me to tell good from bad.  What I managed to learn was that a dacron cover has superior life to nylon and is one of the indicators of a superior product, as is the amount of elongation that the product will permit.  Try it.  Cheap stuff does not stretch as far as the better stuff, and feels quite different.  OK, not exactly the definitive guide to things Bungee, but it's a start.

Cut it, terminate it.

To cut it, tape first with masking tape then use a hot knife.  I bought a soldering gun with a cutting tip on kijiji, and it works well enough. 

To terminate, use stainless hog rings and the appropriate crimp pliers.  Was not able to find these easily in Toronto, but in fishing communities where lobster traps are used and maintained they are commonplace, as are the better grades of shock cord.

Easy.   All the right stuff is in the photo below, followed by a shot of crimped hog rings on the original shock cord.

Old vs new.

When I dismantled the spinnaker pole and looked closely at the original cord, I could see a construction quite different than I was used to seeing.  See below.   The old stuff, (white) with two layers of braid looks as though it would have greater ultimate strength   and perhaps a more specific extended length than the new stuff.  the rubber cores are different as well.  Though obviously expired, it had not failed in use.  I expect the newer stuff would have snapped.  Perhaps this older style material still exists?