Crack in the bilge where mast meets bottom hull

[catalinasailing]

Hello,

I would like to get your opinion if you have any prior experience with a crack in the bilge area where the mast meets bottom hull. It is a Catalina 320, 32 feet boat. I am posting few pictures of the issue areas. Boat is hauled out and there is no crack in the bottom exterior of the boat. Boat is not taking water. The crack goes from left to right, then up, then, to the right direction, total around 10-15 inches. In order to understand how deep the cracks are, I have used dremel tool to grind before posting these pictures. Pictures 3 and 4 are zoomed in to show the depth of the vertical crack area after I used dremel to further grind. In vertical crack (in the middle that goes up down), white substance comes out mostly and it is softer compared to left and right cracks.

Questions:

1. Are the darker areas (dark gray) on left and right cracks, fiberglass ?
2. How deep the fiberglass is in these catalina boats ?
3. Based on the pictures, what do you see ? Is the cracks on left and right deep into fiberglass as opposed to cosmetic ?

Please let me know your experience and thoughts.

Thanks in advance.

[Bellinghamster]

That crack is likely from stress to the keel stub - probably had a hard grounding sometime in it's life. The white stuff is filler/gelcoat. The dark is fiberglass laminate.
The solution is to grind it out to the depth of the crack, tapering away from the crack, then lay up new laminate with laminating epoxy or vinylester resin. Plenty of how-to videos on youtube.

[Lee Jerry]

Is this the front of the keel? They look like the forward keel bolts, and it looks like damage from a grounding.

I would think that the dark grey was fiberglass, but it doesn't really look like it is. Maybe it's just the pictures but it looks more like filler to me; the color is off. Maybe grind out a little more in one spot to what's further down/in?

Is this a new-to-you boat? Is it a new crack, or just recently discovered of unknown age?

[catalinasailing]

Yes, this occurred after grounding the boat. That area corresponds to forward portion of the keel and its bolts.

What I am concerned is, how much can I grind it ? If I keep grinding the there is fiberglass crack, then, I do not want to grind to a point where I end up reaching the bottom of the boat fiberglass and sink the boat.

If you zoom in to the pictures, it shows some more details about the cracks.

How far shall I keep grinding ?

[Lee Jerry]

Well, I'm not there looking at it in person, so take this as random advice from some schmuck on the interweb...

The cracks are not in the bottom shell. They are in the stiffening structure - looks like the longitudinal stringer (on the left) and a transverse floor or bulkhead (on the upper, right of pic). The bottom shell is down by the keel bolt, under the nut. So you should be able gouge out as much as you want (horizontally) without water being an issue. You should hit the "core" of each structure (if it has one, like foam or wood in the stringer) once through the skin or the other side (if a bulkhead). The crack is open already, so if water ingress were an issue, I would think you'd already be seeing that.

Even if/though the crack is not in the shell, ideally the boat should still be pulled for the repair so that the weight is taken off the keel and the crack closes before being re-glassed.

[Jammer]

IMO based on the photos:


- Yes the grey is fiberglass. The softer white material is unreinforced polyester.

- It's hard to know for sure how thick the fiberglass is. That's a heavily reinforced area. Guessing an inch if it's solid. There might be core behind it, in which case the fiberglass will be less thick.

- The cracks appear to me to be structural in nature.


In a less confined area the good fiberglass would be beveled out at around 16:1 and the repair made with layers of glass cloth. Due to the tight space and high loads it will be tricky.

[neilpride]

The ideal would be to remove those 3 keel bolts and laminate that whole area, my 2 cents that there is a serious crack on the outside.

Patching where the crack has appeared is a poor patch, I would not take it easy.

[michaeld]

Just a recommendation.... Take it for what it's worth. Contact Catalina. Ask for their input. Try to get the lay up schedule from the manufacturing process.

[Wolfe10]

Originally Posted by michaeld

Just a recommendation.... Take it for what it's worth. Contact Catalina. Ask for their input. Try to get the lay up schedule from the manufacturing process.

Yup, give Warren Pandy at Catalina an e-mail of the photos and then give him a call.


Wish you had pictures of the outside to see if there is any damage to that area.