Well, sea trials of my newly pre-bent Tornado rig with updated sails were going great...15kts, good power and sail control. Hardened up for another windward leg, loaded up downhaul to max grunt (8:1) and honked in the mainsheet...BANG! The hook at the top of the mast fails and the main drops. Limp home on jib alone.

The hook was not made for the modern prebend loads...metal is about 2.1 mm thick, other boats I compared it to in the yard were nearly double that at 3.8 mm. One 1/4" monel rivet pulled out as the hook bent.

I've sourced a Hobie 18/20 hook which mounts on the opposite side of the mast (starboard) so no worry of fatigued aluminum. Hobie hook is thicker/larger with 6 3/16" rivets. This is made not to pull out of the plastic comptip, so it otta hold real well in alu. Will drill it out to 1/4" and slap in new monel's. Might need to flatten the curve of the hook a bit prior to installing.


Mike.

If you use the H20 Hook, make sure you use the proper rivets and back it up good otherwise this could happen once you put some downhaul on the main. "See Attachment"
This is from a friends H20, he did no get one of the rivets through the top casting properly and I in turn went to give it some downhaul and Wham, this is what happened.
Good luck with your conversion!!

THanks for the response...I can see why it would fail on the CompTip plastic mast if you don't go thru the casting. The Tornado is all Aluminum with no casting at the top...just a sealed (welded) end. Those look like 1/4" rivets on that hook plate...my source told me it had 3/16".

I had to change the hook fitting on my Hobie 17 when I ripped the "hook" off the end.
It was on of the early ones which had the flipper gizmo on it.
It was very thin, like yours, compared to the new ones.
I was told that the biggest, thickest hook fittings came on the Hobie 21 (SE, not the Sport Cruiser).
I didn't have time to order one, so I put a Hobie 18 hook fitting on.
It has bent a little, but doesn't seem to be in danger of breaking off.

I have heard of people who through bolted the fitting on the Hobie 20.
No rivets to worry about.
There is a plug below it so it can't leak.

Try the Marstrom swivel lock...... I sheared 3 of the old ones but the new one is alot thicker and looks like it will handle it perfectly.

You realy put alot of load on that poor hook on a Tornado

I had to act fast...I'm preparing for a race this Saturday. Went with a locally available Hobie 18/20 hook. I had to bend it to fit the Tornado section...but it looks way more meaty than what was on there...plus it mounts to the undamaged side of the mast.