mast repair

[mikee33]

in reviewing your suggestion i am thinking of a patch.. with a plug to reestablish horizontal ness..is there a particular alloy or gauge of aluminum i should seek for this? am also thinking should i bed with 5200 ? am assuming stainless screws.. would 5200 help slow electrolysis there also? thanks for availing yourself to us average boaters..

[Brion Toss]

Hi again,
Any spar alloy will be fine. Avoid "aircraft" aluminum. Bushings' walls should be at least 1/8" thick. And never, I repeat never use 5200 for this kind of job, nor most other jobs. A little UHMW tape or similar will serve to isolate the doubler from the mast. Fasten with a multitude of flathead machine screws, all bedded with Tef-Gel. Be sure the bushing picks up mast well as well as doubler. Ideally drilling for the bushing will get you to sound metal.
Fair leads,
Brion Toss

[mikee33]

a neighbor sugested aluminum rivets over ss.screws.. do u have a preference? alum is more compatible with the mast., rivets less likely ot work loose.. i wonder about the strenght tho.. i see many two part masts appear to be riveted. i took some photos, grinded off the lip formed, feel like am ready to fabricate a doubler n bushing..now to find a piece of spar aluminum... thanks much for yr words of wisdom..

[mikee33]

with the weld broken on the cmpression tube its not doing its job..th doubler would have to cover the tube end.. would this b adequate?..do i still avoid welding?

[Brion Toss]

Hello,
First, rivets are stronger in shear than in tension, so if there's a place for them, it could be here. But screws, properly isolated, are better still. As for the compression tube and its weld, just ignore it; with a proper length on the bolt thread you don't need a compression tube. Instead, get tang bushings, and drill to suit. The idea is to get a bearing on more wall molecules with a larger hole.
Fair leads,
Brion Toss