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Mast Base Repair
http://www.hobie.com/au/en/forums/viewtopic.php?f=14&t=57748		 Page 1 of 2
Author:  Cdubb [ Tue May 24, 2016 7:39 pm ]
Post subject:  Mast Base Repair
Hi all,

I have a early 80's H16 that the mast base broke free on today while stepping the mast up. It's different from some of the other photos I've see of this online. You see the cast base its self had the tops of the rivet holes break away on both sides, while the rivets are still sitting pretty in the mast. From my reading it sounds like using two rivets on each side of the existing hole is a common repair, is this acceptable? Also what material should these rivets be made of and what size and length? Mind you I sail on freshwater and I'm not a racer (if that matters at all).

Thanks and regards
Author:  smattie [ Wed May 25, 2016 4:08 am ]
Post subject:  Re: Mast Base Repair
My '88 had the exact same thing happen. I purchased 3/16" stainless steel rivets (solid bottom) and added several more to the existing base as there were at least two other predrilled holes in the mast (though you'll have to drill through the base casting). Make sure you purchase rivets with the correct grip range. It's important to use stainless as the shear strength is much higher than that or the more common aluminum rivet. Also, you'll need a pretty hefty rivet tool as most "handyman" rivet tools are not capable of the higher strength to pull these bigger rivets. I purchased my puller and rivets at Grizzly Imports. I ended up buying (2) different grip ranges and used the tool and rivets to make a variety of repairs (tiller for instance). I caution you NOT to use these rivets on any other mast repair as you need to use a rivet cap that seals the mast. Monel is another material that most Hobie suppliers sell. For your repair you can stick with stainless (monel has no steel whatsoever and is highly corrosion resistant, but any 300 series stainless performs just as well - your kitchen sink is stainless steel). In the end, I've ZERO issues with the (5) rivets I installed.
Author:  ASDASC [ Wed May 25, 2016 10:47 am ]
Post subject:  Re: Mast Base Repair
Just above the mast base, there should be a mast plug of foam that is sealed in with lots of goopy silicon sealer. Therefore, it isn't critical that the rivets be the sealed type. They do need to be Stainless, as mentioned.
Author:  Paullg [ Wed May 25, 2016 12:56 pm ]
Post subject:  Re: Mast Base Repair
My 1986 did the same thing. I used 3/16 stainless steel rivets as suggested. I have had no problems with the base since I did this. Good luck now off to find my upper mast hole.
Author:  Cdubb [ Wed May 25, 2016 6:04 pm ]
Post subject:  Re: Mast Base Repair
Thanks for the replies everyone. I ordered some rivets from Fastenal today, 3/16x3/8 small head stainless all the way around. 8 bucks for ten of them so should be a cheap fix. I have a air rivet gun and a little air compressor so should have no issues getting them on there. I saw all the grey silicon RTV looking material in the mast looks like new and it looks to be holding strong so I don't think I have to re-seal that.
Author:  ASDASC [ Thu May 26, 2016 8:19 am ]
Post subject:  Re: Mast Base Repair
Sounds like you are good to go! It is a little scary at first until you get it apart and realize how simple it is. It is an easy fix.

I had the same issue, and I think everyone who has done it is a result of the mast link not making the proper transition from down to up (or is it vice versa?). Is there a trick to getting that to work right? It must be a technique, as some folks never have a problem and others always struggle with it. I am wondering if it has to do with where you grab the mast to raise it initially. I grab it further forward on the tramp, and some guys start to lift it from way back on the back rail.
Author:  smattie [ Thu May 26, 2016 1:06 pm ]
Post subject:  Re: Mast Base Repair
The further back you lift from, the better. It is a simple matter of geometry. The issue with lifting too close to the base is that the mast base "lifts" instead of pivots as it is supposed to do. Start further back and you'll not have an issue.
Author:  Cdubb [ Thu May 26, 2016 4:32 pm ]
Post subject:  Re: Mast Base Repair
It's baffled my dad whose a H16 sailor of 40 years give or take. He said he's never had a base break off or had a mast not go in the pocket when stepped. You guys are correct the ball part of the base was hitting the front lip on the boat portion of the base. My dad way thinking the step link was to blame. Maybe, maybe not but acer it gets fixed we will be far more careful.
Author:  Cdubb [ Thu May 26, 2016 4:45 pm ]
Post subject:  Re: Mast Base Repair
It really amazes me that from the factory they only put two rivets in the base
Author:  cpnsoo [ Thu May 26, 2016 9:46 pm ]
Post subject:  Re: Mast Base Repair
I have found when stepping the mast to have the frame of the boat either level or low in the bow. Then the mast drops right into place. If the bows are too high the mast will tend to bind, and cause problems.
Author:  ASDASC [ Tue May 31, 2016 8:42 am ]
Post subject:  Re: Mast Base Repair
You are correct, when I do it bows down on the beach it works much better.
Author:  rattle 'n hum [ Sun Jun 05, 2016 7:26 am ]
Post subject:  Re: Mast Base Repair
Cdubb wrote:
It's baffled my dad whose a H16 sailor of 40 years give or take. He said he's never had a base break off or had a mast not go in the pocket when stepped. You guys are correct the ball part of the base was hitting the front lip on the boat portion of the base. My dad way thinking the step link was to blame. Maybe, maybe not but acer it gets fixed we will be far more careful.


Your Dad is correct.....a worn/broken/bent step link can cause this to happen. When working properly, the base pivots on the lower pin of the link until the "shoulders" of the link hit the sides of the slot in the mast step. Then the base rotates on the upper pin to guide the ball of the base into the cup.
Author:  ASDASC [ Mon Jun 06, 2016 9:53 am ]
Post subject:  Re: Mast Base Repair
Really? I will have to check that out next time. I may have an issue that needs to be repaired.
I did step the mast this weekend, and standing back on the crossbar until the mast was fully up with my arms extended really helped.

Cdubb, your comment about only two rivets - that was my initial reaction as well. Then I realized that if the link works correctly, there is very little force on any of the parts. When the mast link does NOT work as intended, no quantity of rivets will protect from the forces you can exert with a 26' lever. Using only two rivets leaves you room to add more during your repair.
Author:  Cdubb [ Fri Jun 10, 2016 2:26 am ]
Post subject:  Re: Mast Base Repair
Well all is well with my Hobie now, used a punch and 4 rivets, it drilled like butter. It indeed was the mast step, last it was up someone didn't pull the pin that hooks it to the mast and sailed it my dad figures. This badly damaged the hinge and we neglected to see it on our first attempt. Used a new hinge after the repairs and replacing all the cleats and the cheek block, which we discovered to be trashed and it went perfectly. Mast is stepped and waiting for a favorable wind. Thanks to you all for your assistance. Cheers!
Author:  rattle 'n hum [ Sat Jun 18, 2016 12:54 pm ]
Post subject:  Re: Mast Base Repair
Glad this worked out....it's one the (many, many) things that I learned the hard way!
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