Cracks on the Deck

[Mark Matthews]

The former owner of my Morgan 25 let the chainplate on the starboard side loosen, allowing water to seep below deck, a small section of the main bulkhead to rot, and the torque at the foot of the mast to cause stress eggshell cracks on the deck where it meets the cabin. I have replaced the bulkhead section, but should I open up those hairline cracks and then re-glass the area, or should I trust that water won't penetrate such thin cracks since I don’t perceive any delamination?

David

Mark Matthews responds:

David,
It's hard to know what to prescribe without actually seeing the damage. Given the chance, water will get into anything it can. On that note, it might be worthwhile to enlarge and fill the cracks. My sense is that they are trying to tell you something else, and may just reappear if you fill them.  I'd suggest looking at the bulkhead below, which sounds like it is presenting a sharp surface that is causing the cracks. You may want to have the load supported by a larger area, perhaps by glassing in foam on either side of the bulkhead to distribute the load more evenly. Check out Don Casey's book, This Old Boat, which I found very useful on a recent haulout.

I hope this helps, and feel free to bounce any ideas my way.
Mark Matthews