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 Post subject: split the mast
PostPosted: Mon May 25, 2009 8:42 pm 
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Joined: Wed Apr 25, 2007 11:40 am
Posts: 18
Location: North Dakota
Matt, I have a 1998 Wave.

OK, stupid me, Even though I had never had water in it before, I still should have checked the mast to see if there was water in the lower section when I stored it for the winter.

Apparently there was quite a bit, as I now have a 8 inch lengthwise split in the mast, about 18 inches up from the bottom of the lower section.

What are the pros and cons of getting a guy at a friend's shop, where they rebuild WW II Mustangs, (great at welding aluminum), to try to salvage this mast. It's hard to find better welders.

I think I'm ready to try it, depending on what you and they tell me.

I would guess the cost of a new lower section with be, shall we say, expensive.

thanks for your input, Paul B


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 Post subject: Re: split the mast
PostPosted: Tue May 26, 2009 8:26 am 
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Joined: Thu Jul 12, 2007 2:40 pm
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Location: Coushatta, LA
I am assuming that the water froze, expanded, and cracked the mast? Ouch, that sucks.

However, you should probably spring for a new lower half. Welding sounds sketchy. Recoup your loss by selling the cracked mast for Al salvage.


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 Post subject: Re: split the mast
PostPosted: Tue May 26, 2009 9:21 am 
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I have not heard good things about welding aluminum, so may not work. Aircraft repairs are done with lots of rivets... so maybe that would work?

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 Post subject: Re: split the mast
PostPosted: Tue May 26, 2009 6:51 pm 
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Location: Detroit, MI
pdbaker wrote:
Matt, I have a 1998 Wave.

OK, stupid me, Even though I had never had water in it before, I still should have checked the mast to see if there was water in the lower section when I stored it for the winter.

Apparently there was quite a bit, as I now have a 8 inch lengthwise split in the mast, about 18 inches up from the bottom of the lower section.

What are the pros and cons of getting a guy at a friend's shop, where they rebuild WW II Mustangs, (great at welding aluminum), to try to salvage this mast. It's hard to find better welders.

I think I'm ready to try it, depending on what you and they tell me.

I would guess the cost of a new lower section with be, shall we say, expensive.

thanks for your input, Paul B


The problem with welding Al is that you lose the strength of the heat treatment in the welding heat affected zone.

However, given the location of the split, and its orientation (longitudinally), I think you'll be OK welding it closed. The forces on the weld will be lengthwise (either in compression or tension) - the best possible orientation. Bending stesses are lowest at the ends of the mast, so that shouldn't be a problem either.

When you talk to the welding guys, tell them it's probably a 6061 T6 alloy and to use a little heat as possible with the TIG welder.


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 Post subject: Re: split the mast
PostPosted: Tue May 26, 2009 6:58 pm 
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Joined: Thu Jun 05, 2003 9:57 am
Posts: 1601
Location: Clear Lake Iowa
I was going to say the same thing. :roll: Actually, I was thinking duct tape.......


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 Post subject: Re: split the mast
PostPosted: Tue May 26, 2009 8:06 pm 
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Joined: Thu Jul 19, 2007 5:46 am
Posts: 77
Location: Brookings, south dakota
Paul : I would think that a good certifed welder could weld up that mast and not lose any strength. So go ahead and try If it doesn/'t work you can always get a new mast.


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 Post subject: Re: split the mast
PostPosted: Wed May 27, 2009 7:57 am 
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Location: Coushatta, LA
clark wrote:
Paul : I would think that a good certifed welder could weld up that mast and not lose any strength. So go ahead and try If it doesn/'t work you can always get a new mast.


If it does not work, you will have paid for all the welding stuff and wasted the time involved with all that, and then your going to have to buy a new lower half anyway. You KNOW the new part from Hobie will work.


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 Post subject: Re: split the mast
PostPosted: Wed May 27, 2009 2:17 pm 
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Joined: Thu Jun 23, 2005 12:55 am
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Location: Rapid City, South Dakota
clark wrote:
Paul : I would think that a good certifed welder could weld up that mast and not lose any strength. So go ahead and try If it doesn/'t work you can always get a new mast.

You may not loose any strength from the welding but you wont gain much back either, the best bet is to not waste your money and just buy a new lower mast half from your local dealer. Sorry for your loss. :-(

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 Post subject: Re: split the mast
PostPosted: Wed May 27, 2009 2:42 pm 
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Joined: Mon Jul 04, 2005 10:13 am
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Location: Nepean S.C. Ottawa, Canada
Many years ago, I re-sealed the base of a H16 mast (Club boat).
The next week, our Vice-Commodore capsized then turtled the H16. Took us an hour and two power boats to pull the mast out of the mud. You got it, water leaked into the mast, and was well trapped by the well-sealed base.

Six weeks later, we packed the boats away for winter. There was no apparent sign of water in the mast. Six months later, we unpacked the boats, only to find that we had a mast with a split in it. Boo hoo. We sold the damaged mast to someone who wanted a flag pole.

Matt B, would a sleeve work? like 15" or 18" of sheet aluminum, shaped to the same contour as the mast, then rivetted to the mast? My thinking is that the rivet holes would likely weaken the structure. Weld & rivet?

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 Post subject: Re: split the mast
PostPosted: Wed May 27, 2009 3:27 pm 
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Location: Detroit, MI
John Lunn C A wrote:
Matt B, would a sleeve work? like 15" or 18" of sheet aluminum, shaped to the same contour as the mast, then rivetted to the mast? My thinking is that the rivet holes would likely weaken the structure. Weld & rivet?


Like I said originally, welding is not a bad idea in this case. Essentially, you're just sealing up the crack (Wessell's joke about the duct tape is really not that far off.)

The position and orientation of the crack are key. Aluminum welds are poor in tension across the weld - somthing that this weld will never see.

If this was a mast break, then sleeving would be the call. If the split were transverse, then I'd suggest welding, then riveting a plate (made from another piece of mast) to cover the weld. Epoxy and limited number of rivets to attach the plate.


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 Post subject: Re: split the mast
PostPosted: Wed May 27, 2009 3:43 pm 
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Joined: Thu Jul 19, 2007 5:46 am
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Location: Brookings, south dakota
Talking to paul and finding out that they welded the mast in about 1/2 hour and didn't charge him a thing would say Paul choose a logical choice of trying the welding first before having to buy a new mast. Out here in South and North dakota they do very fine work.


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 Post subject: Re: split the mast
PostPosted: Fri May 29, 2009 6:14 am 
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Joined: Wed Apr 25, 2007 11:40 am
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Location: North Dakota
Thank you for all your input. Keep up the discussion.

OK, here is my update. I'll let you know if this "fix" worked at the end of the summer. If it doesn't work, I'll let you know how the swim back to shore was.

When I took the mast to the P-51 Mustang welder, right away he noticed that this was not the first time the mast needed repairs. There is a previous weld, from a previous owner, lengthwise close to the base of the mast. Since I've been using the mast for 3 plus years with no problem, I take that as a positive for trying another weld.
Here is the link to a pic of the previous weld. It runs lengthwise, from the left of the arrow to the cleat. It is about 6 inches long. It's been grinded down, and I just didn't notice it before. (I could never be a detective.)
http://www.flickr.com/photos/38884077@N05/3576028396/

So, the welder did his thing with the new split in the mast, and you can see his work at the following link. He thought it might be good to have more than the single weld at the split, to possibly give more support. Pic is prior to painting.
As I said, I'll let you know how it works. If it doesn't, I'll let you now how much a new mast costs, and how cold the water was. http://www.flickr.com/photos/38884077@N ... otostream/

Hope the links work, and thanks again for your thoughts
Happy sailing! - Paul B.


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 Post subject: Re: split the mast
PostPosted: Sat May 30, 2009 4:45 am 
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Joined: Mon Jul 16, 2007 7:58 pm
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Location: Indianapolis, IN
To make sure I didn't have this problem, I drilled a tiny weep-hole in the luff track just above the mast base, and another just above the top seal (below the comp-tip). So water can seep out before it freezes there, but won't get in when capsized.

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 Post subject: Re: split the mast
PostPosted: Sat May 30, 2009 5:30 pm 
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Joined: Wed Apr 25, 2007 11:40 am
Posts: 18
Location: North Dakota
you anticipated my next question, where to drill holes. I don't want this to happen again.
thanks


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 Post subject: Re: split the mast
PostPosted: Sat May 30, 2009 9:52 pm 
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Joined: Mon Jul 16, 2007 7:58 pm
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Location: Indianapolis, IN
Use the smallest bit you have access to. Dremil-size is fine; just enough to let the water seep out. The lower hole should be about an inch and a half up from the mast base. For the upper hole, I removed the comp-tip and used a stick to meausure the depth to the seal, then I drilled the hole just above the top of the seal.

Normally, rain water collects in the gap below the comp-tip, and can seep around the seal into the lower section. You may have seen a cup or so often spills out when you separate the mast sections.

Some people have reported getting water inside the comp-tip also, so maybe a similar hole in it would be helpful too. I haven't encountered that problem.

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