Hey, everyone. I was out over the holiday weekend and forgot to pull the pin that holds the base of the mast steady while stepping the mast. While I was down there trying to pull it out, I noticed that the cast base of the mast is somewhat loose in its connection to the long extruded section of the mast. I could see the crack between the two pieces get larger and smaller as the mast shifted. Seems like there are only two rivets holing the two pieces together. Can I just drill the rivets out and replace them, or do I need to put rivets in other places around the mast base, as well? Thanks for any tips or advice you might have. -Matt
You could replace the rivets, but the holes are probably enlarged from corrosion, so new rivets might not work too well.
There should be three rivets - one on each side and one in the front. If the one in front is missing, you could pop one in there and tighten it up.
The only time that the rivets are even stressed is when you step the mast. When sailing, the mast is under compression. When you step / un-step the mast, the rivets are under shear as the base tries to pivot off the mast extrusion.
I have actually done that same repair. Depending on the age of the rivets, they eventually loosen up. I was able to just drill them out and replace them. It worked for me. You have nothing to loose in trying that first. The problem you may encounter is if the holes have actually widened because of the movement. In that case you will need to either use a larger rivet and/or drill new holes.
Make sure you seal the rivets and the mast base with silicone. Not as important as holes near the top of the mast, but if you turtle, it will keep water out. It is actually a good idea to have a small drain at the bottom of the mast, just in case your mast isn't completely sealed, to let water out. The mast is upright most of the time, if you're lucky anyway. 🙂
Hope you are successful. Let us know.
Sail Safe. HD.
I had the same problem a while back. The little hobie bracket they give you with the boat to step it where you put the two pins through and all that is a little bit off. With mine I always had to really work it around to get the pins all the way in because it barely fit. then when you start to tilt the mast down, in order to get it to come all the way down you have to actually pull it up and out a little bit. This isn't a problem if you're doing it by yourself, but I had one guy letting out a rope tied to the front stay and me on the tramp so that way we wouldn't drop it by accident. Since all his force was pulling the mast base down and forward, i couldn't get it to pop up and back and the base thing got stuck in the joint and wouldn't tilt all the way back. The mast still did though, and it sheared all three rivets. Then the mast didn't completely come off the base luckily because it was stil being pulled down towards it. I still haven't bothered to fix the problem because as it was already mentioned here, the mast is usually under compression and doen'st even need those rivets. About sealing the bottom though. If you flip the boat the tip of the mast is going to go in the water a litle but the base should be a few feet in the air, so it doens't seem like it would need to be sealed at all. Then again i guess it couln't hurt as long as the mast can drain somewhere. how big of a drain hole is ideal?
How far does the cast aluminum base slide into the extruded portion of the mast?
since mine didn't come all the way out i'm not exactly sure, but i'm pretty sure it's about an inch. not very far anyway. I imagine the part of the base that is inside of the mast extends the same distance above the rivets as below. Thats how the mast head is anyway.
might be 1.5 " - if you encounter a lot of play (hole to rivet) due to corrosion, you could decide to place additional rivets in holes that you creat. IIRC the mast top can have a variety of rivets holding the top on the mast (I think the # of rivets has changed over the last 35 years) - this might be true for the mast base as well.
Patrick
yeah very true. What I said only applies to a particular mast head. whats disappointing though. when I replaced mine because the old one broke. The new one I got from Hobie was a complete peice of crap compared to the original. The original one is nice thick metal and has a pretty big pulley, that thing was solid. The new one feels like I could bend it in half with my bare hands, and it has two dinky little plastic pulleys. what's the world comming to.....
So it finally didn't rain here for a weekend so I got to go finish my fiberglassing and while I was there I checked out my mast. The base of mine is only held on with 2 rivets (I guess there are a few different types). But what happened what, the rivets didn't actually shear at all, the holes on the mast were just so close to the edge that they tore all the way out! Now I'll have to drill new rivet holes in different places, I think I will put these a little further from the edge.
I would recommend sealing the bottom of the mast also. Last weekend a 16 turtled, and in no time the mast was full of water since its leaky base was under water due to turtle position. Perhaps a removable plug in the base would be a better idea.
Greg
H16, H14
Yup; I'd seal the mast top and bottom. A bit of spray foam covered with silicone does wonders. 
the removable plug sounds like a really good idea. although I have never had a boat turtle without water already getting inside the mast, I guess it could happen if the wind hits the tramp just right. better to be prepared for that just in case.
im noticing that when i sail my mast is starting to bend slightly up on the fiberglass tip, i think its safe to assume it could be from the age of the boat, but is there any way to fix it? could i just flip the mast over and store it the other way for a while to bend it back?