Stress cracks in Stainless Steel Arch on my Hunter 306

[Brinky63]

While doing the monthly maintenance SS cleaning on my Hunter 306 arch I noticed some stress cracks. The pictures show the small hairline cracks on the support pipes (port side both) and the plate that holds the boom traveler (also port).

Has anyone experienced these type of cracks and can these be grinded out and rewelded to keep it's strenght?

 

[jssailem]

Those cracks are serious. Something occurred and will require structural repair.

 

[rgranger]

I agree with @jssailem
I would consult a local welder who does stainless

 

[JamesG161]

The Arch has the Traveler Stress on it.

Needs welding or the Boom will lift and be a big issue.

Jim...

 

[kloudie1]

All of those resemble poultice corrosion..Intergranular corrosion from being covered and remaining wet .. it looks as if the straps that went around the tube did not breathe and water remained to corrode the stainless. A stainless sleeve could be welded over the corroded area .. or a new tube installed. That can't be fixed.

 

[jaysweet]

Wow! I have a 2004 306, and I've never seen anything like that. It's hard to believe! Frankly, the arch is so tremendously oversized that I can't see normal tension from the boom causing it. I really have no idea how you should handle it.

 

[JamesG161]

the arch is so tremendously oversized that I can't see normal tension from the boom causing it.

When I took Materials Engineering our Professor told us this example.

"Take a Walnut and hit it with a Big Hammer, the Walnut is crushed."

"Take a Walnut and hit it with a tiny Tack hammer, it may take 1000 hits to break the Shell."

Jim...

 

[Brinky63]

Thanks for the feedback. Already in talks with welder(s) on island. The arch was never covered with any cables or straps. We do sail in heavy winds at times and have had the main fly across during a jibe in heavy winds that rocked the arch.
We just repaired the life line stanchion bases on port side (arch issues are also on port side) due to corrosion, the bow stanchion was made new. The slip is 90 degrees in the wind coming from port @ an average of 15Knots or higher daily. That might be the cause of salt penetration into small cracks that only get worst over time.

Will keep you posted on next steps.

 

[JamesG161]

That is a stress crack , rare to happen unless Oxygen is starved from the Stainless Steel. That is why @kloudie1 suggested the strap preventing Oxygen.

Jim...