Mast welding cracks

[gray_sailor]

Hi!


I am looking at the boat from 1982.

It has Isomat mast, which has hallyard and sheets blocks attachment points welded onto it.
I have noticed cracks around welding seams.
This really makes me worry.

Do you think it is possible to do some maintenance for those welding seams or does a mast need full replacement?

[Compass790]

It is possible to reweld those fittings but IMO they were done badly in the beginning.
They should all have a thick compensating plate on the bottom of the fittings shaped to fit the mast to spread the load.
However they lasted a fair while as is & not uncommon to see them like that. You need to have someone that knows what they are doing.

Yes it needs to be done asap.

[Manateeman]

It would be better to have a plate bent to the shape of the mast under the gooseneck ? ? fitting but the crack on the left photo does not look terrible...drilling out the ends and welding it might do the trick. I can’t see the crack on the right photo well.
In general, it’s difficult to weld something very thick to something thin. Welding over an existing weld on an aluminum mast is difficult. It’s a lot easier to weld a larger plate or weld the eye or whatever to a plate OFF the mast and then attach it to the mast with bolts or rivets.
I can’t see how you would need a completely new spar.
Find someone who welds a lot of aluminum.
The manatee crew.

[Jim Cate]

The cracks don't look too bad to me (possibly because of the photo quality). Unless you anticipate going well offshore in the near future, you could try drilling "stopper" holes at the end of the cracks and continuing to sail for a while, inspecting frequently. If they do not propagate further, I'd say sail on!

If they do propagate, or other cracks develop, then one of the more substantive fixes outlined upthread will be appropriate.

Jim

[C420sailor]

It looks like your cracks are all in areas of extensive pitting. The result of impurities maybe? Weird.

[Dave_S]

I'm with Jim, I don't really see a problem. My eyes are a bit dodgy but the only thing that looks like a crack isn't along stress lines so I'm not sure it's a stress crack.

Maybe I'm missing something but if your worried have someone come and have a look. Someone specialising in aluminium welding.

[Compass790]

Originally Posted by Manateeman

It would be better to have a plate bent to the shape of the mast under the gooseneck ? ? fitting but the crack on the left photo does not look terrible...drilling out the ends and welding it might do the trick. I can’t see the crack on the right photo well.
In general, it’s difficult to weld something very thick to something thin. Welding over an existing weld on an aluminum mast is difficult. It’s a lot easier to weld a larger plate or weld the eye or whatever to a plate OFF the mast and then attach it to the mast with bolts or rivets.
I can’t see how you would need a completely new spar.
Find someone who welds a lot of aluminum.
The manatee crew.

If you look at his sheet block brackets they are thick welded to thin, piece of piss to do if you know what you are doing.

Agree he can make new brackets off the mast & doesnt even need to shape them for the sheet block mount as a couple of bits of flat would work if you just cut them to go to the edge of the bend.
I'd cut both bits off clean it off & start again. Any decent welder could do in situ with a bit of windbreak cloth.

[gray_sailor]

Just to clarify the exact location of those problem places with cracks and more details about the extent of cracking, I am posting couple of additional pictures.
In fact, entire welding seams are covered with cracks and pitting.

I really think they are bad and can not be left like this, because the boat is being considered for quick circumnavigation (one round in 1.5 years) and the spar is going to take a load.


Thank you for your ideas and opinions.

[Jamme]

Could you add a mast step / halyard organizer at the base of the mast?
Something like this:

[gray_sailor]

Originally Posted by Jamme

Could you add a mast step / halyard organizer at the base of the mast?
Something like this:
Attachment 239583

Jamme, yes. I am really thinking about something like this. But it should be for keel stepped mast.

[Jamme]

Originally Posted by gray_sailor

Jamme, yes. I am really thinking about something like this. But it should be for keel stepped mast.

Sorry, I had not realized it is a keel stepped mast. My bad. Then perhaps a collar bolted or riveted around the mast at deck height?
Good luck!