Crack in hull rib

[SabreToothedEngineer]

I'm a relatively new owner (four months) of an '83 Hunter 34. I just discovered a crack in the FRP next to a keel bolt in the shower sump. I don't believe it is structural (I'm a mechanical engineer, recently retired) but wanted other's opinions.

The crack is on the side of the hull rib that goes under the compression post (and before anyone goes there, I know about the compression post issue, and it appears to have been addressed on this boat). There is no matching crack on the other side of the rib or the other side of the keel.

I believe the crack is in a cosmetic cover over the real rib, but can't figure out why it would be on the side and not the top where the maximum stress would be. Or what stress could have caused it.

The pictures came in upside down (don't know why, they're right side up on my computer). Sorry about that.

Any thoughts?

 

[mz4wheeler]

Not a big deal. I have those next to my engine.

 

[kloudie1]

Looks cosmetic to me . Looks like a crack in some too-thick gel coat on the rib. My bet is that the area is under compression there from the weight of the keel pulling down..(except when the boat is being supported by the keel on the hard. Also, it doesn't look from the picture that the crack goes all the way down to the keel bolt backing plate bearing surface. Can you probe it to see how deep it is?
I've attached a picture of mine.. You can see how thick the beam is where they drilled for the speed/depth sender wires to pass through. If you zoom in you can see some spider cracking in an area right next to the backing plate. Interesting that on my '85, the sump pump hose location is different.

 

[splax]

Perhaps a crack in the relatively brittle gel coat from a shock load to the keel from hitting/running aground ? I believe I have a hairline crack in that location.

 

[waternwaves]

grounding flexure

agree, and it probably not the only location.,

just the most visible