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Replace mast base vs reinforcing mast
http://www.hobie.com/au/en/forums/viewtopic.php?f=14&t=53657
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Author:  brewer3287 [ Fri Jan 09, 2015 11:09 am ]
Post subject:  Replace mast base vs reinforcing mast

I have a 79 hobie cat which 4 riviots from the mast base have broken through the bottom of the mast. What are your thoughts on re-rivioting vs reinforcing the mast then re-rivioting? If reinforcing the mast is needed (which i suspect), what material would you recommend?


Author:  Fxloop [ Fri Jan 09, 2015 11:58 am ]
Post subject:  Re: Replace mast base vs reinforcing mast

Have the old rivets ripped out and tore the holes on the mast itself? Or is there a lot of corrosion ect where it looks like new rivets won't hold good? All I've read on this site suggests NOT trying to weld or heat up the aluminum. If it were my boat, I'd prob carefully and cleanly cut off the bottom 3/4" of the mast and start with a nice clean edge, drill new holes and pop in new SS rivets.
If your mast isn't torn you could try bigger SS rivets? small washers bent and glued inside the mast lining up with the existing holes with a bit longer rivet to grab onto the washer from the inside.

Have any pics of the mast base you can post here?

Author:  ASDASC [ Fri Jan 09, 2015 3:15 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

I would also add that if the bottom of the mast itself is NOT all thin and corroded, but just the holes were torn out, I would move over a bit and drill new holes.

Just be sure to seal up the old holes to keep the mast from being waterlogged when you flip it.

If you don't flip it, you aren't sailing hard enough!

Author:  GD_NC [ Sat Jan 10, 2015 7:02 am ]
Post subject:  Re: Replace mast base vs reinforcing mast

Assuming your mast is in good condition, and you plan to use new base, you might want to replace the mast step at the same time. The new parts are much different than the 1979 version and the rotation stops on your base are probably completely shot if they are original. A new step/base will allow you to carry much more mast rake. It will also allow you to use more recent shrouds and sails intended for a much more aggressive rake angle than the older boats had.

Author:  brewer3287 [ Sat Jan 10, 2015 8:59 am ]
Post subject:  Re: Replace mast base vs reinforcing mast

Here is the dropbox link to the picture of the mast. Garrett, I live in Raleigh area also, specifically Wake Forest. Do you know of anyone who works on hobie cats in the area. I've had difficultly finding anyone.

https://www.dropbox.com/s/he3ebcn3l0ial ... 8.jpg?dl=0

Author:  Fxloop [ Sat Jan 10, 2015 6:54 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

Doesn't look too terrible! remove all old rivets, drill new holes 1/2" away from old holes, pop in new rivets - maybe add an extra one or two, then seal the area really good with silicone. If your mast base is under water, you've turtled and your boat is upside down hahaha. do make sure your mast doesn't leak anywhere when your done tho. Clean mast with acetone and silicone all rivets over the whole mast and around the comp tip joint if your mast has been upgraded.

Author:  GD_NC [ Sun Jan 11, 2015 6:16 am ]
Post subject:  Re: Replace mast base vs reinforcing mast

brewer3287 wrote:
Here is the dropbox link to the picture of the mast. Garrett, I live in Raleigh area also, specifically Wake Forest. Do you know of anyone who works on hobie cats in the area. I've had difficultly finding anyone.

https://www.dropbox.com/s/he3ebcn3l0ial ... 8.jpg?dl=0



Hey, sorry for the slow reply. No, there is no Hobie Sailboat dealer anywhere near here. That said, i'm happy to help you. Will PM you my contact info.

I agree with FXloop's assessment. If the base is not damaged too severely, you could easily reattach it.

Good luck.

Author:  rattle 'n hum [ Wed Jan 14, 2015 12:03 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

If the base itself has enough good material to re-rivet, then I agree with the above recommendations, except..... There's really no need to seal the base. There should be a foam plug a little ways above the base. While the base is off, I highly recommend that you inspect, push, and prod the plug to make sure it's sealed and immobile. If not, remove it, drain the mast, clean everything up, and reinstall/reseal.

The base is in compression except while stepping/lowering the mast, so you really don't need a ton of holding power. Three to four long, well placed 3/16" stainless or monel rivets will do it. Do a search for tips on removing the old/installing the new rivets if you're new to it. Dealing with rivets is not that difficult, and it's something you'll do a lot if you have a cat for very long.

That damage likely occurred from a shock load while stepping/lowering the mast, which good technique will minimize. However, if it's 36 years old, these things must be expected!

Good luck!

Author:  PCBScotty [ Mon Jan 19, 2015 1:23 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

My mast step holes broke where the pin goes. I'm trying to replace the Step, I drilled out the 4 rivets but cant pop the step off. Is there something else holding it on?

Cheers.

Author:  MBounds [ Mon Jan 19, 2015 2:42 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

PCBScotty wrote:
My mast step holes broke where the pin goes. I'm trying to replace the Step, I drilled out the 4 rivets but cant pop the step off. Is there something else holding it on?

Cheers.

Nothing but age and corrosion. Heat (gently) and persuasion will eventually free it.

Author:  Tim H16 [ Mon Jan 19, 2015 3:39 pm ]
Post subject:  Re: Replace mast base vs reinforcing mast

A couple of years ago I also replaced the wornout Mast Step on my H16 following Matt Miller's "Getting in Step" article:
http://www.hobiecat.com/support/pdfs/h16-step-replace.pdf.

The old mast step was fused to the dolphin striker post due to saltwater corrosion over 30 years. With a sawzall and wedge I had to cut the old mast step casting into 3 pieces in order to free it from the post and crossbar.

To get the new mast step casting to line up with the top of the crossbar (old style without integrated track) and with the dolphin striker post I had to do some filing to get it to fit. The threaded hole for the post in the new mast step casting was about 1/4" aft of the top of the post. I had to slightly enlarge the aft side of the upper striker post hole in the crossbar (as Matt recommended). I also filed down some of the aft edge of the crossbar (where the casting "hooks" over it) and slightly filed down the inside of the lip of the casting where it "hooks" over the the crossbar.

Loosening the nuts on the dolphin striker bar was also interesting. One of the nuts broke off wit part of the threaded dolphin striker bar, fortunately there was enough thread left on the bar that I could put a new nut on it. The other end's nut came off fine.

After filing and using clamps, the new casting now fit nicely on the crossbar. I couldn't figure out how to drill exactly through the new casting into the old rivet holes of the crossbar so I drilled fresh holes through the casting and crossbar and riveted. Make sure you do not try to drill new holes thru the back of the mast step/front cross bar where the tramp track is located, since you will not be able to pull rivets there.

Author:  PCBScotty [ Tue Jan 20, 2015 9:46 am ]
Post subject:  Re: Replace mast base vs reinforcing mast

I did use that pdf file.
Striker nuts removed no problemo. I've been hammer the crap out of the striker pin and don't want to damage it. So I'm guessing I'm going to have to get some anti corrosion spray. Or cut it like Tim H16 said

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