Author Topic: Keel leak or blisters - any idea what this is?  (Read 1616 times)


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Keel leak or blisters - any idea what this is?
« on: May 01, 2020, 03:01:29 am »
Just discovered two similar leaks midway back on the port side of the keel, and I'm stumped as to what they are.  She's a CSY33 and was on the hard this winter, we had a very mild winter here in Connecticut and dipped below freezing only ~1-2 days this year.

Do these look like run-of-the-mill blisters, or might there be something more significant/structural going on since they appear to share a similar horizontal crack, with what appears to be a black-ish fluid weeping out (I couldn't determine if it's water or oil/diesel, however).  Could there have been water that froze in the encapsulated lead within the keel and expanded to cause the small cracks, or do these look less worrisome?

First time I've seen this issue and not quite sure what to make of them...any advice/info/theories would be greatly appreciated, thanks in advance!  Photos attached:

Soggy Paws

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Re: Keel leak or blisters - any idea what this is?
« Reply #1 on: May 01, 2020, 09:32:05 pm »
I was the owner of a CSY 44 WT for 20 years.  It had significant blisters to start.  Your problem does not look like any blistering I have ever seen. 

Are these leaks in line vertically with the bilge sump?  Do they line up horizontally with the bottom of the sump or are below it?  Are the leaks petroleum products like oil?  If so I would recommend thoroughly cleaning the bilge sump and have a good look for penetrations into the fiberglass walls or bottom, like screw holes or a crack.  You will eventually need to grind out the exterior leak sites and seal them.  But first you need to find the source and extent of the leaks, flush a cleaner through them, and then seal them from the inside.  It's important to get rid of as much of any oil as possible before making the repair.                                                                                                 
Once you have done the sump cleaning and found the source you might consult with an experienced blister surveyor regarding other repair options.  He will charge you for his time so do the cleaning and looking yourself first. Good luck and keep us posted.                                                                                 Dave
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