Hairline crack in nesting bulkhead

[Aphers]

A few weeks we were motoring our Spindrift 11N through some chop and came off a wave with quite a bang. I thought I might have heard a bit of a crack.

Sure enough a few days later I spotted a hairline crack in the paint. It's at the nesting bulkhead- stern section, port side, at the top bolt hole.

I've finally found a chance to take the dingy out of use for a few days and get it on deck and in two sections.

Good news is it really is just a hairline crack. I've sanded down to bare wood and it's hopefully visible in the photo. There's no sign of movement or any gap trying to open up. I suspect it only goes through one or two layers of the plywood.

 

What's the best approach to fixing this? I was thinking of sanding back enough of the ply to get depth to apply a layer of light glass cloth. But I'm worried about adding any extra thickness and interfering with the bulkhead joint.

What about using a dremel to chase out the crack and open it up, then neat epoxy followed by micro fibres? That would certainly be a lot easier.

Easiest of all, of course, would to just saturate the whole area with neat epoxy.

Any thoughts appreciated- I'd like to get the boat back in the water in a couple of days if possible.

[Designer]

There should have been several layers of glass sandwiching the bushings. I don't see why you can't just add them now and sail on. 

[Aphers]

Ah so I haven't built this as strongly as I should have originally. Seems like a good chance to do something about that.

[dwg2116]

As long as the sander is out and warmed up,  and you will be touching up paint anyway,   Do the other holes have glass over them?

 

For Graham,   This looks like very light woven finish cloth,    Should we be using biax in places like this?   

For the Spindrift in particular, is light weight a big priority over brute strength?     We amateurs tend to habitually overbuild, putting a little extra on when in doubt and weigh down the designer's carefully thought out balance between weight and strength.  

 

If this boat had been built to your plans, would there not have been a problem?

[Hirilonde]

As I recall, from almost 20 years ago, the nesting bulkhead to side corners receive 3 layers of tape, unlike all other corner taping.  I just made sure to get 3 layers over the bushings at the same time. I had an issue with the outwale trying to release from sides at the nesting bulkhead in one spot.  After regluing it, I added a small patch of glass over the end ot the outwale onto the nesting bulkhead.  So far so good.