Crack in bilge under mast compression post

[Dpmmvc]

I have a vertical crack in the bilge under the compression post (I believe that’s what its called) my mast doesn’t go through the cabin all the way to keel but sits on top of cabin. The boat is a Catalina 30. Can someone look at the photo I’m attaching and tell me if if there’s cause for concern?? My bolt on keel Appears to be in perfect shape from examining it from the outside of the boat...

[s/v Jedi]

You have to grind out the crack until you get to fiberglass laminate to see if that is cracked as well.

[Dpmmvc]

I lighted the picture and circled crack

[s/v Jedi]

Originally Posted by Dpmmvc

I lighted the picture and circled crack

Yes, the picture was clear and crack visible. You’re looking at a thick coat of filler, not the laminate, which is why you need to grind it back to the laminate to see if there is a structural problem or not.

[Cadence]

JMHO It appears the crack if in some kind of filler which has no tensile strength. Your hull probably flexed which is normal and the filler cracked. I doubt it is a big deal.

[Chuck Hawley]

You have a tremendous advantage over the owners of either one-off boats or boats with very limited numbers of boats built. There are, what, 5,000 Catalina 30s around? (I know someone will correct me with the correct number; feel free to do that!)

Check out the Catalina 30 forums under "hull cracks" and I think you'll find what you're looking for. I agree with the respondents that the first thing to do is to remove what appears to be putty or some non-structural filler and see what lies beneath. But do as the owners as I suspect a high number know the answer.

Chuck

[Cheechako]

Yes, try Catalina or forums. That's a healthy crack, but often there is gel coat sprayed thick in places like that to make it look decent. It's brittle and any flex it cracks.
Other than that, as Jedi says, you'll have to grind to tell if it's just cosmetic or a real crack. It is stressed there from the mast compression...
But if it's actually moving much I would expect to see cracking in the floor surrounding the mast support base.

[psk125]

Is it actually a crack that you can stick a blade into, or is it just the dark, dirtied edge of a roughly-cut layer of fiberglass roving? Hard to tell from the picture. If it’s a crack, time to grind. If it’s just dirt, go sailing.

[Cheechako]

My guess is it's plywood covered with glass. Ply doesn't crack. Thick glass doesn't often either, but that looks like chopper gun, cosmetic stuff. You could stick a blade in there and see if you can pry a big chip off to see what's under.

[Mike Banks]

That sounds as though the rigging has been extremely tight, or the vessel has hit something submerged or perhaps a passing tree or bridge support, or overhead wire.

If you are storing a vessel in a cold place over a winter, it is a good idea to make sure your rigging is backed off on the screws. Especially fore stay and back stay tensions since they are usually even longer than the shrouds and have even more potential for contraction..

If you have seriously damaged the hull integrity in any way, it can be fixed. The question is--is it worth doing it? It is a massive job to fix it properly. The biggest cost in so doing is like as not the time spent on the hard in a boat yard--because it is going to be a long job. Weeks rather than days if you are doing it yourself--and you will need to use epoxy resins to get an adequate bond..

[Jim Cate]

f you are storing a vessel in a cold place over a winter, it is a good idea to make sure your rigging is backed off on the screws. Especially fore stay and back stay tensions since they are usually even longer than the shrouds and have even more potential for contraction..

Seeing that the thermal expansion coefficients for aluminium (the mast material) are considerably higher than that of stainless wire, I suspect that the rig actually looses tension when subjected to low temperatures rather than gaining.

Jim

[a64pilot]

Your correct, old larger airplanes that are aluminum with steel control wires have Springs in the control wires to keep them from getting too loose at altitude where the aluminum airplane shrinks more than the steel wires.

[nortonscove]

Looks harmless enough. If the boat is on the hard just go outside and tap around the area. Compare it to the healthy glass nearby and if it sounds solid don't worry. If it doesn't sound solid as in a very defined sharp sound you may want to start grinding a little. It looks very much like my Mirage in that area and it's mostly cosmetic.

[RSB333]

This appears to be a crack in the bulkhead - not the hull. And, as pointed out, it's likely the bulkhead is plywood coated with fiberglass or chopped roving. It's not likely to be a serious structural problem.
RSB333

[Spot]

Catalina 30 Compression Post thread
If that is the bulkhead directly below the compression post it is weight-bearing, or at least weight-distributing...yes?