Aluminum Mast Repair
 

Hi All

New member here.. I have a small issue with my Aluminum Mast. Its off a J-36 and where the upper shrouds attach there is wear, deformation and small cracking. The boat was built in 1984 and am sure this has occurred due to stress on the uppers and age. Rigging is Rod.

The area is within a tapered section of the mast - above the jib/spin halyard sheave box and just below the jumper strut.

Short of sending the rig to a local spar builder for repair, I believe all that is needed is the cracks to be stopped and a larger stainless plate be added to each side of the rig where the upper shroud attachment passes. Tig welding the cracks are a possibility or stop drilling the running crack.

Looking for a little confirmation that this is the most likely repair or if I may be missing an important point.

Look forward to any comments or additional ideas for an appropriate sound repair

Yikes
 

Hello,
That is a very high-load area, and it has been highly-loaded for a long time. Tune, load amplitued, scantlings, and install quality might also have played a part in the deterioration. Aluminum is amazingly resilient material, but even it has its limits. I certainly would not count on stop-drilling here, as I've seen cracks leap right past the stops on more than one occasion, in similar circumstances. Welding seems also to be a very bad idea here. Short of a new stick, the best option might be to replace at least the top of the mast, with an internal sleeve. This is a heavy and stiff solution, but it's the only one I'd trust.
Fair leads,
Brion Toss