SailNet Community banner

1 - 16 of 16 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
I have a 1970 Contest 30. It's been sitting on a trailer for a long time. Recently I noticed some cracks and discoloration on one side of the hull. I am trying to figure out if these are blisters, cracks, or what. The boat has an encapsulated ballast keel. There is a deep bilge about where the cracks are. The bilge is dry, even after severe rain, which makes me suspect that rainwater has been getting into (and through) the fiberglass out from the bilge. Any help and advice appreciated. I am trying to sell the boat, and I don't want the next owner to sink with it.

-R
 

Attachments

·
Registered
Joined
·
1,555 Posts
Only way to find out is to open up that area with a grinder. If it is wet inside then it will have to dry out before it can be re-sealed. Wet material may have to be removed and replaced. I would find a good surveyor to look at it. No way for anyone here to give you a definitive answer.
 

·
Tartan 27' owner
Joined
·
5,242 Posts
It doesn't look like blisters to me.
There definitely has been moisture weeping out of those crack(s) though.
This is something I'd want to have fixed before trying to re-float that boat.

Tim R.'s repair advice is spot on.
 

·
Registered
Joined
·
1,073 Posts
The thing that concerns me is the coloring. Looks like corrosion of metal but that doesn't make sense. What could be near enough to the surface to corrode like that? What is the ballast?
 

·
Registered
Joined
·
3,184 Posts
So my best guess would be water penetration between the ballast and the fibreglass, leading to corrosion between the two and thus forcing the fibreglass layer outwards, leading to cracks.

That is just a guess, though.
 

·
Registered
Joined
·
4,762 Posts
Certainly looks like cracks in the fiberglass encapsulating the keel. If the ballast is iron (which is likely) you have a big problem. As the iron rusts, it expands and that can cause major damage.
 

·
Member
Joined
·
599 Posts
IMHO, unlikely to be blisters.

TimR gives good advice,

I am not familiar with the layup of your boat, but many boats with encapsulated ballast also have a "false keel", generally astern, to increase the keel size beyond that of the ballast alone. Builders often put all sorts of junk in the false keep to help fill the void without using expensive epoxy. (I pulled out milk jugs in a previous boat). Sometimes the false keel voids then fill up with bilgewater, which can't escape, and so works its way out through the keel. Often it can react with the epoxy becoming highly acidic, making matters worse.

So:
Best case: False keel cr*p. Grind, let drain, fill properly, check /repaint bilge.

Bad case: Water has penetrated around the ballast in the encapsulated keel, rotting the 'glass (yes, glass cloth not fully whetted out with epoxy can rot) possibly loosening the ballast within the keel. I have heard - but not tried: Drill holes, drain, try injecting epoxy, maybe acetone first to really dry/clean things - keep fingers crossed.

Worse case: Penetration to a cast iron ballast. Corrosion of ballast. Cast iron does not rust much, but given enough time a saltwater it will rust and expand, potentially cracking open the glass encapsulating it. Let's just hope it isn't that.

Good luck!
 

·
Dirt Free
Joined
·
2,659 Posts
Glass cannot rot.
An epoxy hull is extremely rare. Contest 30's were built using polyester resin not epoxy. You will only find epoxy hulls in very high end boats.
 

·
Registered
Joined
·
4,635 Posts
Looks like a core of boiler punchings. Cutting out a panel of the glass will tell how bad it is. On wooden boats with internal ballast poured in concrete the iron chunks swell with rust, forcing the planking and requiring a whole bunch of nasty hammer and chisel activity.
 

·
Member
Joined
·
599 Posts
boatpoker, you are correct, glass cannot rot...but from direct experience: I had to work on a boat with a compromised keel where there was a layer of black mush with fibres embedded in it that certainly looked "rotten" - clearly the remains of mat which was not fully whetted out. Possibly a batch of epoxy was improperly mixed, resulting in a "soft spot" too deep to show as a blister? Anyway, this was in an epoxy hull boat; I have less experience with polyester resins.

I *think* - and am more than willing to be corrected - that some roving is not 100% glass, but sometimes a glass/polyester mix. Also open to other suggestions.

So I a probably off base here, but the problem looked almost identical - and I stick to my hope it is a "false keel" problem!
 

·
Registered
Joined
·
364 Posts
On the hard for a while, and she has purged herself of moisture. Great. Open up the crack, epoxy it closed. Done. Sell the boat.
If you want, and I maybe wrong, but then take advantage of the hulls dryness and put on a barrier coat all over it, for the next owner. Super.
 

·
Registered
Joined
·
295 Posts
I had the same problem with my Caliber 33 which has an encapsulated keel. There was a crack in the bilge (bad repair job by a PO) that allowed water from above to leak down into the keel and eventually out through a spot low on the keel. I drilled out the spot where the water was seeping out, to find that it had undermined the concrete the builder had used to fill in the spaces around the iron billets used for ballast.

We started the repair with a temporary repair in the bilge to ensure no more water would pass through. (Also put a new mast boot on the mast at deck level).

On the keel, we ground out an area about 2 feet across, brushed out all the loose concrete, put a heat lamp on the area from early May until mid July. Then repaired the area using a rust encapsulating 'paint' on the exposed iron, filled with a hydraulic, vinyl concrete, laid up multiple layers of glass and faired out with epoxy. Then went back to the bilge, ground out the temporary repair, and effected a proper repair of the bilge with several layers of glass and epoxy.

Since these repairs were beyond my skill level, I paid the yard to do the work. Total cost was about $2500, of which $2000 was labor. The iron only rusted after it was exposed to open air, so rust was not an issue. As the water ran into the keel, it had followed the seam between the glass and the ballast, so the whole keel was not affected. So fear not; the problem you face is probably not catastrophic and cost of repair might not break your piggy bank. And odds are that, after repair, your boat will out live you and her next owner.:)
 

·
Senior Moment Member
Joined
·
13,283 Posts
Looks like iron oxide weeping through a coating. Since you say you have an encapsulated keel, my money is on a leaking encapsulation.

I'd grind it open to see what I was dealing with.
 

·
Registered
Joined
·
174 Posts
I would agree with the theory of ( punchings ) ...Problem becomes rust is on the order of seven times the volume of iron...
 
1 - 16 of 16 Posts
Top