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repairing cracked mast with welding
About a week ago i posted regarding my mast which is cracked above the second spreaders ( and about 15 inches above the running back tangs). I came to the consensus, with advice from others including a rigger who i trust, that the cracks should be ground out, through welded and a plate welded on over the sheave box area. The plate itself ( as of now ) is an elongated diamond ( about 15 " total) with a rectangular mid section (about 3") which will be centered over the sheave box housing. The plate covers both the cracks, which spread aft about two inches on either side from the bottom two screw holes of the sheave box ( see pictures).
Before i have this plate welded on for good i would like a second opinion. The mast is a proctor, which is 47' and only 6"x4" and has a good deal of flex. Even with running backs secured, there is flex to some degree through the entire mast, and especially above the running backs while sailing hard to weather.
The mast is ~ 1/8" thick, and the plate is a good 1/16 thicker than the mast walls. I fabricated the plate out of a broken spar.
Will there be any structural issues with having the stronger and thicker plate welded over the more flexible thinner mast walls?
Would it be better to have the same thickness of aluminum for the plate?
Any other issues/advice?
Thanks in advance for the feedback and advice!