Hair Line Cracks

[dakuehn]

Powerwashed the hull yesterday and am seeing some hair line cracks in the gel coat (or epoxy) restricted mostly to the encapsulated keel. Not at all widespread, just here and there and never more than an inch in length. These are not starbursts, just a single, hair line crack. Now I am considering stripping the existing bottom paint and going back with an epoxy water barrier and new bottom paint--any need to go beyond this solution?

[paulk]

What's underneath (or inside) the keel? If the keel is cast iron, you could have rust expanding inside and cracking the encapsulation. Are you sure it's the gelcoat itself, or could it be paint? Exactly where do the cracks appear?...Pictures? Also useful... what do the resident yard "experts" who watch every boat get hauled suggest? Sometimes they know more than you might think at first.

[dakuehn]

Thanks Paul--I am kicking myself I did not bring a camera to the site (it is many miles from home). The boat is an S2 with a lead keel. I was told this boat had the gel coat stripped and an epoxy job done 4 years ago. The areas I am looking at have had all of the bottom paint removed.

[dakuehn]

I sent these (photo1) and (photo2) to CP via email a couple of days back, but would appreciate other feedback as well. The two options I was considering: A medium sanding and going back with ablative (not worrying about these hairline cracks); or stripping and applying a barrier coat. Thanks

[hellosailor]

d-
You say on the keel, but those photos look like they are on the hull proper, not the keel or keel stub. If they are on a coating on the keel itself, I wouldn't worry. If they are on the hull, more exploration might be in order.

[sailingdog]

Umm... can't really see any cracks in either of those photos... probably due to the size and compression of them.

[dakuehn]

HS--thanks. These concentric hair line crack areas do appear on the hull proper as well--the original message was misleading. As SD suggests, they are hard to see--they are all small in length. Thanks

[hellosailor]

Concentric hairlines, as in circles, more or less?

I'd guess that means blisters were filled, and the fillings were popping out, or at least, the fillings and coverings over them were expanding/contracting at different rates. I hate to say it, but if the budget at all allows, yeah, I'd want to strip it down and find out what the root problem was. If there aren't many of them, maybe just grind down each one, fill and fix locally.

Because covering it up will just be a stopgap measure at best. Could just be some patches were rushed or mixed poorly and didn't cure properly, could mean you need more work.

Was there any warranty? Or can you contact the folks who did the job?

[dakuehn]

HS
The powerwash took the paint off of these areas leaving bare circles, but the cracks are through the middle of the circle. They don't look like areas repaired as a result of blisters, but the boat did have a bottom job done 3 years ago by a previous owner where an epoxy barrier coat was applied. Now, tell me it is ok to just sand and paint....

[Sailormann]

I would suggest you take everything off the bottom so you can see what it is. A powerwash shouldn't leave holes like that. I wonder how thorough or patient the PO was with the "bottom job". I think you might find it a good idea to take off the gelcoat and get a proper epoxy bottom put on. In the long run it's going to be cheaper then trying different things every year.