Mast Torn at Base

I'm rebuilding a 1972[?] Hobie 16. I noticed that the mast base was flopping around when I first stepped the mast. I removed the mast base from the mast and saw that both rear rivets weren't connected to anything--the base had fractured away from the rivet holes. So I ordered a replacement base.

Due to the flopping around (probably during stepping/unstepping), the two rivets at the front of the base have managed to tear the mast extrusion. :-( There is a portion of the aluminum at the front of the mast, between where the rivet holes are, that is dangling. It looks like I could pull it off with my fingers. The remainder of the mast extrusion isn't damaged. No part of the tear is progressing UP the mast, and there's no cracking around any other rivet holes.

My first thought was to saw off the bottom 3/4" of the mast. Then I thought about the sail geometry, shroud length, and other considerations. I would hate to ruin the boat, trying to have a solid mast base.

Since about 80% of the mast is undamaged, and I can drill new holes in good metal to attach my new mast base, should I just forget about the torn part?

Rick

Sounds like a similar situation that I experienced except in my case the damage was self induced. First time to step the mast, separated the mast base from the mast with the mast step acting like a can opener, like most lessons this is one I'm not likely to forget since I learned it the hard way. Fortunately the mast base wasn't damaged but the rivits did pull thru the bottom of the mast, according to experienced hobie sailors of the day the fix was as easy as drilling new holes in undamaged locations and reviting together. This occurred back in 2003 and so far so good......Good luck with your fix and make sure to watch your mast stepping technique assuring the ball of the mast base is aligned to the mast step before that last final push-up.

I think that either method would work good for you. Cutting 3/4" off the bottom of the mast would be fine and the shroud lengths can easily be modified with the shroud and forestay adjusters.
As long as there are plenty of good material around the base, drilling for rivits in new locations should work fine also.
Jack

Your best bet would probable be to just drill new holes, and re-rivet it. Maybe add another rivet or two, to keep the new holes away from where the worn rivets were located. cutting the mast down would probably be fine as well, but i don't know that you would have anything to gain. If the first repair fails, then try the second.

I had to do the same repair on my mast. I just redrilled the holes in new locations. It's actually kind of a funny, all be it embarrassing story about the first time I ever stepped the mast. I had just bought my boat and my dad, who used to own a Hobie but sold it to help with medical bills as a result of my introduction to the world, and I were going to step the mast. Keep in mind he hadn't done it for 20+ years and I had very little knowledge of Hobie sailing or any sailing for that matter. I laid the mast on the tramp, connecting the mast step link, and he instructed me to begin raising the mast. Forgeting that it is always more than a good idea to connect the shrouds we began the lift. As the mast became almost vertical I heard a little "pop" and told my dad that I couldn't get the mast to stop. "It's falling!" Luckily he and everything else was out of the way and other that the rivets ripping through the bottom of the mast everything was ok. It was a pretty nice introduction to the design of this great boat as well as some good repair experience.
If you can I would just re-rivet and be sure to do a leak test in the unfortunate event you go turtle.
Good luck
James

I had this same problem. I took a 2.5 in wide strip of galvizined sheet metal and rapped it around the base of the mast using JB weild to hold it in place drilled and re-rivited. Seems to be just fine.

Great advice! Thank you all very much. I'll definitely seal the base to the mast when I re-rivet it, to keep the air inside. And I'll be double-careful when stepping the mast, as suggested.

I have NO experience with Hobies, and didn't know what to pay attention to when stepping it the first time in my driveway. The ball wasn't aiming at the socket, even though the hinge seemed to be working fine. The next time I'll be watching it, making sure the alignment is good AND the ball will be going INTO the socket as designed.

It's good to hear that there are several options open to me. I sure appreciate the quick response to my question. It makes it fun.

Rick