Hi David,

My quip was not quick enough to get in before your clarification and at the same time, too quick. This subject is not too deep for me after all.

Re:
1) - so, you were motoring or sailing downwind through at an extremely low tide?

2) - I would chase each of the cracks with a burr, not a disk grinder. A disk grinder will not reveal the crack in the same manner as a burr since it can fold over clean material and you think it doesn't go any further.
My favourite burr looks like the "pointed tree" SG, on this page:
http://www.boggstool.com/page2.html
- when the cracks have been hogged out to bright metal (you cannot see the crack anymore), you can fill & fair with epoxy filler and tape as per recommendations. Remember to apply epoxy to lead on a freshly exposed surface only, as it starts to oxidize right away. A quick run over everything with a wire brush should do the trick. - if you excavate down to the keel bolt, don't panic! clean way some more and pre-treat with phosphoric acid (and wait 24 hours) to "kill the rust" around your S/S keelbolt before proceeding with above.

- this repair assumes the keel-hull joint is tight, otherwise crevice corrosion can still occur since source is a different path.

- I am skeptical that these cracks are due to haulout on a railway. Lead is such a ductile material that a point load stress at the bottom is not resolved as a stress crack at a location that has a much greater area of support. I believe the indications should be near the bottom of the keel if this case.

        Cheers, Russ
        Sweet 35 mk-1
        PSW, east Vancouver island

At 07:26 PM 03/10/2014, you wrote:

Two related issues:

1) I found an uncharted rock at low tide this summer so am now having a mast out/keel off repair by a reputable yard near Sidney, BC. Since my draft is slightly more than the 2 meters Canadian Hydrographic set as their minimum for charting obstructions I guess they are off the hook. 2) However – the keel has shown minor weeping from a spot on the port side corresponding to about the lower end of a keel bolt - seen at haul outs since purchase about 6 years ago. At least two surveyors have seen it and ignored it. Usually there is a teaspoon or two of water and a bit of rust seeps out over 24 hours or so. This time there are two spots. While removing the keel (as per #1 above) light grinding over the area shows a fine vertical crack a couple of inches long and a couple more smaller cracks on other spots further back in line with bolts. On this thin keel the aft bolt is only about ½” diameter. I had been told earlier at a Rendevous that the trickle, etc could be caused by impurities in the scrap lead used by Mars originally. At purchase and since then there has been noted a very slight cant to starboard over the whole keel (maybe ¾” at most) again noted but ignored at surveys. The yard is telling me several things and I am interested to know if anyone else with this keel has seen similar issues. Among the suggestions I have heard by the yard so far: do light grinding of the area then prep and patch with mat/epoxy to seal; or do the patch and also an overlay of fibreglass to give more strength (neither of which would be guaranteed); or consider a new keel(!). They seem certain the cracking is stress on the keel compounded by annual hauling at our Club marine railway for yearly bottom prep, etc; they’ve also indicated they would contact Mars for advice. My concern is that none of the suggestions sound like a final solution if they are correct in the analysis and reasoning. There are also concerns re crevice corrosion in the long term in any event.

So: If anyone has heard of and or dealt similar issues I’d appreciate feedback. I hope to contact Rob at Southshore as he had the original information that scrap lead used in that era was the culprit and essentially a cosmetic issue.

Thanks folks. List advice is a great asset.
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