Interior Structural Cracks

[JamesG161]

I have noticed these cracks after inspection I did following heavy seas and pounding my keel once in 4 foot sea against a shallow sand bottom. I looked at earlier pictures before the "single bang" and they are there and appear to be non-propogating.
I had my boat surveyed in Jan 2014 and there was no mention of these cracks. Since the survey, my Hunter 430 1997 has seen 10 hours of continuous 8' seas initial the delivery and I have since been anchored in 6' seas for 4 hours, and several 4'-7' seas storms. My boat just "yawned".

Are these mid ship beam cracks normal?

Suggestion of seriousness and/or repair techniques would be appreciated.

The starboard side crack in the worst and is thumb nail inserted width at the widest point.

See photos...
There no other visible cracks in the Fiberglas® structure.
Jim...

 

[Crazy Dave Condon]

This is an area where after the hull was constructed that white gel is usually brushed on and that gel coat over time will crack which is cosmetic. You have no leaks but take a flat head screwdriver and take off the gel coat covering to see if it is simply loose gelcoat. If so, I would not sweat it but if there are cracks in the what I call the tabing, have someone who knows glass and gel or a professional to look at it.

 

[Paul Cossman]

I had similar cracks around the base of my rudder post on my Passage 42. A surveyor wrote me up for them, so I took a grinder to that surface gel coat and found that it was superficial and only on the surface. After prepping the ground away surface with some acetone I glassed over it and added a couple of layers of additional fiberglass for good measure. It made the surveyor happy, took very little time, and I felt better knowing it was only superficial.

 

[JamesG161]

I took a grinder to that surface gel coat and found that it was superficial and only on the surface. After prepping the ground away surface with some acetone I glassed over it and added a couple of layers of additional fiberglass for good measure.

Good idea! Since I posted that, I have had Fiberglas® (FRP) expert tell me it is a "stress crack" and not "structural". He suggested a very small hole drilled at the end of the crack to relieve the stress and to fill the cracks with resin when laying up a "X" pattern of a overlapping FRP mat.
Thanks!
Jim...

 

[shemandr]

Here's some shots of damage from a low speed hard grounding. I hope they are helpful.

 

[JamesG161]

I hope they are helpful.

Yes they are! I will let my FRP guy look at your picts.

You must have had a good WHACK!
Jim...