Hobie Forums :: View topic - Freeze crack in mast base

Hobie Forums http://www.hobie.com/au/en/forums/

Freeze crack in mast base http://www.hobie.com/au/en/forums/viewtopic.php?f=20&t=22613	Page 1 of 1

Author:	blord5 [ Sun Mar 28, 2010 6:37 pm ]
Post subject:	Freeze crack in mast base
I've discovered a 4 inch crack about 1 foot from the bottom of my mast. It runs parallel to the mast and is over the junction of the sail track channel with the main body of the mast. I believe water must have sat in the mast and frozen (there is slight bulging of the mast in that area) during one of the several winters it has sat out unattended before I bought it. Wish I'd seen this before now. Haven't used Snapfish before so hope the image shows up. Does this make the mast too unsafe to use, or can I seal up the crack (not really open) to prevent leakage, or have the crack welded? I've read many posts about the pros and cons of welding, but not sure if there's a consensus. Would trying to repair it make it weaker?

Author:	Sail Revolution [ Tue Mar 30, 2010 1:54 pm ]
Post subject:	Re: Freeze crack in mast base
That makes me nervous. Call your local Hobie dealer and see if they have any leads on a used mast.

Author:	mdgann [ Tue Mar 30, 2010 9:25 pm ]
Post subject:	Re: Freeze crack in mast base
That is a scary looking crack. How far from where the boom is set? This is a critical point on the mast that is loaded very highly. Welding any metal will change the physical characteristics of the material. Some aluminum alloys should never be welded while some are more conducive to welding. Whatever you weld, you will be introducing an area that will be more brittle than the rest of the material. Usually in thin materials, like the mast, as soon as the welded area is asked to bend, cracks will begin to emanate from the area. In aircraft skins we usually patch with the same material and rivet the patch in place with a bedding compound between to take up any small gaps. This puts the rivets in shear, so solid rivets would be preferred. I don't know how far up the mast the crack is, or if you could get in there to buck the solid rivets or not. But I think that it is a better option than welding. By the way, it is far better to have a longitudinal crack than a transverse one. It it were transverse I would be telling you to scrap the thing. Good luck.

Author:	blord5 [ Wed Mar 31, 2010 6:26 am ]
Post subject:	Re: Freeze crack in mast base
Thanks. The crack is about 1 ft. from the bottom of the mast, 4" long. You are supporting my thought that the longitudinal nature of the crack is better (at least in a relative sense!) than a transverse defect. My thinking with all I've read here is that welding may make the area weaker and wider than already exists. Since I'm new to the Hobie business and just beginning to bring this one back to life, I may focus my efforts on everything else and stay on the lookout for a used one somewhere in New England.

Page 1 of 1	All times are UTC - 8 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/