small crack at the base of the mast

[jhgreen]

Hello

I went to my yard the other day to schedule my winter maintainance and ask how my mast removal went i was told i have a small crack running up my mast how serious is it and will it excede 1500 the cost of another mast for my boat, i found a used one if it comes to that

Jeremy
Pearsom10m

[Faster]

Definitely need pictures on this one....

[MacGyverRI]

Pics. help a lot.

FWIW, If you have it welded (aluminum?) it has to be "stop drilled" before any welding is done, IF it can be welded.


o--------------o they drill a small hole at the far ends of the crack so it can't travel any more.

[Flybyknight]

Why did it crack? and what's to prevent a replacement from cracking?
If it were my problem, I would weld up the crack and weld in a reinforcement sleeve. imho.
Dick

[jhgreen]

I was told by the yard i have not seen it myself otherwise i would have taken piçtures - it îs stored for the winter so i can't get to it
It is aluminumum and i believe it may habe simething to do with being keel stepped

Jeremy
Pearson 19m

[Stumble]

Jeremy,

It is generally a terrible idea to weld masts. To some extent it is possible to do so if the weld is in a non-critical area and far up the mast (where loads are lightest). In this case it's right at the mast step which is the highest load section. I hate to break it to you, but the only way to weld this would be to weld it up, then heat treat the entire mast again to bring it back up to whatever heat treatment schedule it currently is.

6000 series aluminium (which is almost all masts) is heat treated to 400F and held there for hours. This imparts a lot of the mechanical strength of the part. When you weld a 6000 series alloy it looses all of the mechanical properties of the heat treatment, and can loose as much as 40% of the original strength.

You might be able to sleave the area and reinforce it, but without pictures it's hard to say.

[tap]

Wouldn't the weld, while only 60% as strong as heat treated aluminum, still be stronger than a crack?

[Stumble]

Tap,

Actually it may not be. It is completely conceivable that the mast with the crack is actually stronger than it would be once you weld it (obviously it may also not be). Sleaving here is one option, replacement is the better option. Welding is at best an acceptance that the mast is not up to design strength by a significant amount, and is getting close to the designed safety margins.

[Hudsonian]

When I've seen this it has been because of corrosion on the inside of the mast base. If the crack is short -- say 1/2' -- you may want of cut of the base of the mast.

[Rockter]

Need a picture!
You might be able to weld it.
.