J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Moisture Issue

Hull 25, I acquired it last October, it was previously on Long Island and known as Zantastic.

Do you know or have a reasonable idea as to the cause/source of the moisture? My boat has indicated moisture on the starboard side from about 2 feet forward of the keel to about 2 feet aft of the keel and up from the bottom 2 - 3 feet. I would like to try to dry it out but would like to know where the water is getting in so it does not happen again.

Mine is wet below the waterline from about 2' behind the bow all the way back, and halfway up the transom on the starboard side.

I think the primary source of water intrusion is the engine exhaust, which seems to be an issue with many of the J 30's (there are numerous discusion n this issue on this web site), but I am also planing on having the rudder fittings rebeded along with all of the boats thru hulls just to be safe.

It doesn't sound like your boat has the sme problem though, I would suggest checking the anchor locker and drain, the starboard chain plate & bulkhead, deck fittings and around the keel.

"... I would suggest checking the anchor locker and drain, the starboard chain plate & bulkhead, deck fittings and around the keel."

Thanks for the reply. When I bought the boat there was a significant leak at the starboard chain plate which I sealed up. It had been leaking there for some time as the wood inside the cabin in that area had discolored and had a very small amount of rot. What I don't undershand however is how the moisture could get into the hull via a chain plate leak. Is there a path from the bulkhead core to the core in the hull? I don't know how the construction process went, but I would think that the hull would be laid up and glassed, then the bulkhead attached. Anyone know how the bulkhead and hull are joined? TKS AC

I believe the bulkhead and the hull are tabbed together, so I can't see how water in the bulkhead could get into the hull core.

However, I suggest checking your deck. They just cut a slot through the deck when they installed the chainplates, as opposed to bedding them in solid glass. When I pulled my chainplates, I found a couple inches of core rot in the deck. We dug out the rotted core surrounding the chainplates, dried it, and filled it all up with epoxy, so now the deck core is isolated from any future chainplate leaks.

Try checking your cooler drain. We had issues with ours and it did show as moisture on the starboard side in about the same area.

I am in the process of having my keel redone...grinding out the keel joint, re-fiberglassing and fairing. The guy doing the work for me noticed that when the weather warmed up moisture started to seep out at the trailing edge of the keel, which of course would indicate that water will go the other way when she's in the water.

Has anyone else had this issue and know what causes it, a hard grounding at some point in that past maybe? My boat has moisture up and down the entire starboard side, and I'm thinking that this is probably the major source of intrusion.

Is there any core around the keel joint? I would think that area would be solid glass. Yes, there's vermiculite filler everywhere, but that's not core per se.

I do not think there is a way for water from the deck, like say from a chainplate, via any route to get into the hull. The hull and deck are two different pieces and there should be no spot where there was core to core. The only possibility from the deck would seem to be if someone attached something well outboard like near a stanchion, they may have pierced the top of the hull.

David
#397

I'm doing an extensive recore of the bottom of my J/30 (70% starboard, 30% port under the water line), including all around the keel sump. Core extends right up to the edge of the keel sump, but not down into it (I suppose this could vary by production year). The inner laminate glass over the coring is over 1/2" thick at the edge of the sump and tapers down to about 1/8 as you get to the settee. I've removed the floor to recore from the inside, so gravity is on my side. As several people have mentioned if you have significant moisture in your hull, it will be wettest around the keel sump since the water migrates downward. In my case, the core around the keel was the texture of a firm sponge. Let just say, it was 'no longer structural'. Fortunately, the glass over the inside and the three stringers across the sump prevented this area from developing cracks. I also think that the resin between the balsa squares helped keep the core layer from completely collapsing (think 'resin rivets').

I decided to recore based on a sample of the core (vs simply drilling a hole and poking around). When I cut a square of core out of the bottom it was not well bonded to either laminate (inner or outer) and had greatly diminished compressive strength. And it was wet, which means it would only get worse over time. I tried 'drilling and drying' this fall and winter with no success at all, even with a dehumidifier and heat lamps. I've been told by a source at Waterline that core that is wet with salt water will not dry with this method... I'm not sure if I believe this, but it seems plausible. I think it was simply too wet to dry this way. Even if it dried, I'd still be left with badly weakened core. Its a nasty project, but its going to be as good as new.

I've read a lot of posts about water problems in J/30s (or all J/Boats of this era). This is definitely a common issue in any balsa cored boat with polyester resin and no barrier coat. I'm sure a large portion of the fleet has been sailing for years with a lot of wet core. These boats are rugged, but at some point wet core will get substantially weak and we'll hear about more delamination, blisters that reappear every year, or water weeping out of unexpected places. My boat was infiltrated by simple blistering that was never thoroughly dealt with by the previous owner. The result is a repair that would cost more than the value of the boat at a yard, but one that is manageable if you are crazy enough to do it yourself. I estimate I'll spend about 2k in core, glass and epoxy; god knows how many hours I'll burn up... If you don't have barrier coat, do it now.

I use a Protimeter Aquant moisture meter and I've found to be utterly reliable at gauging the real situation inside the laminate. If it reads over 200/1000 its significantly wet (you can press water out with your fingers and a good hard pinch). If your meter is over 800/1000, it is truly soaked (think sponge before you squeeze it out). I've used it to map out all of the core issues on my boat on both the deck and hull - its always spot on. Be advised that metal will make this kind of meter read false positive. http://www.gesensing.com/products/aquant.htm?bc=bc_ge_protimeter

Here's some information about this project visit http://www.6degrees.com/j30/underthefloor/ , which features revealing shots of under the floor, the keel sump and in the core space. Enjoy.

Also see the thread "Dewatering Aft Bilge - Need Advice" for more information about this project.

Wee!

Rich
Tres Cosas
#294