moisture problems?

David

.
Jun 17, 2004
115
Macgregor 26x Morecambe
I noticed that the fiberglass floor that the mast is stepped on seems moist. This may just be a recent thing (as some water got in the boat recently) or more of a longer term problem (long term water leak at mast?).

Overall, the interior of the hull has worn paint that is useless. It is probably the original paint and has flecked off mostly, though some remains. The fiberglass looks good everywhere except on the cabin floor where it has been discolored by the rusting fuel tanks and the head floor.

When I pressed on the floor of the head (I'll use the word floor here to mean the fiberglass that the mast is stepped on) it seemed moist and a little spongy even. Does anyone know if the glass is solid down to the keel here or if there is a hollow below this area?

I intend to buy a dehumidifier and put it in the boat for a while. Also, I'm ordering Magnaflex Spotcheck in order to evaluate a sample of the fiberglass in this area. I found this website that describes the process in a highly technical manner: http://www.dockwalk.com/issues/2003/aug ... ers1.shtml

Regards,
David
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
I can't imagine a designed hollow in that area David,

a void could possibly exist. The hull is very thick in that area, meant to be solid(more or less) but voids are often found in the full keel area of boats like this. Do you have a metal pan that the base of the mast sits on? Are you sure it is sponghy? Check it again. If the pan is removed, try sounding the hull (tapping) in that area both inside and out. Hollow sounds much different than solid. I will do the same on my boat, it's hauled just down the hill from me.

If your hull was truly sponghy around that mast step, I think the high load of the mast would easily sink into the sponghy area.

Do you have a garboard drain in the bilge to keep it drained while you have it stored? I would install one if it doesn't have one. Even with water coming in around the mast, it seems it would drain away from this area. If you install one, take the time to have it fall as low in the bilge as possible, it will then be bone dry for most of the year.

Any glass I have cut into on my boat has so far seemed very solid and strong. I haven't found any hull blisters either and the boat has never been barrior coated. New England seasons are short, boat in the water about 1/3 of the year.

I enjoyed your pictures of setting the boat in your yard. It looks like you are firmly committed now and the boat looks in better condition that I thought it would be. Keep us posted. Tom
 

David

.
Jun 17, 2004
115
Macgregor 26x Morecambe
not spongy, but maybe some delamination

I checked again and I don't think spongy is the right word. I do think there is a little give though, very little. My best guess is that some delamination has occurred in this area. I would imagine that the right approach is to remove the metal pan for the mast, remove the head walls, door, and supporting floor stringers and then grind a little to get down to some good GRP, then replace the removed GRP. I sounded the area with a hammer and it did not sound hollow at all. It did sound denser around the metal pan, but it sounded pretty good everywhere. Not that I am an expert, but it sounded good nonetheless. I didn't sound on the outside, I'll try that tomorrow.

I don't have a garboard drain installed. That sounds like a good idea though. I'm trying to think of a way to modify the boat to always have a dry bilge. The article that I read said that this was very important to prevent saturation of the keel. For now though, some standing water is still in the bilge.

I haven't noticed any blistering with one exception. The starboard aft topsides has a 4 inch circular convex area. I don't see evidence of any impact on the inside or outside, so I'm guessing it is a big blister. I'm looking forward to taking my hole saw to the middle of that and finding the cause.

My wife is a photojournalist, so she took most of the pictures. The ones that are over exposed are my contribution. I'll take a few more of the current boat stand situation.
 

David

.
Jun 17, 2004
115
Macgregor 26x Morecambe
garboard drain

Do you have a garboard drain in the bilge to keep it drained while you have it stored? I would install one if it doesn't have one. Even with water coming in around the mast, it seems it would drain away from this area. If you install one, take the time to have it fall as low in the bilge as possible, it will then be bone dry for most of the year.
OK, I've been thinking about this for too long, so I'll just ask: Would you mind describing how you installed the garboard drain? West Marine has this one which looks like it's opened from inside the bilge:
http://www.westmarine.com/webapp/wcs/st ... ctId=10337

I've also seen a web site where someone described fiberglassing over the outside of the drain and then breaking the fiberglass to access it! That seems like overkill to me.

The part that I've been thinking about is how to measure where to drill the hole for the drain. Presumably, I'll be outside the boat, guesstimating where the bottom of the bilge is, then I'll drill a hole, go inside the boat and see how good my guess was. Then, I'll rinse and repeat until I end up with a reasonably good guess. Is this how it went for you?

On the original topic of the fiberglass under and around the mast step, I did the following:
1) drilled two holes with a hole saw (about 1 inch deep).
2) put a small screwdriver into the kerf and pryed out on the disk
3) rather easily in both holes, a disk about 1 cm thick came out. This disk seemed to break from the rest of the hull within a layer of chopped strand mat (if that was even used on these boats). The good news is that no real delamination occurred as the disks didn't just come out after cutting with a hole saw.
4) In each hole (after removing the disk that pryed out easily) I tried to pry out another disk. This time, in the first hole, another, thinner disk pryed out with some effort. In the second hole, part of a disk pryed out with a lot of effort (I wasn't sure the screwdriver was going to make it as it was bending a bit).

My analysis of the core/delamination issue is that no serious delamination is occurring. The mat breaking apart is probably due to a little resin starvation in those layers, but probably the hull is adequatly strong.

I've been waiting to post the results of this until I took some pictures to help with the visuals, but I'll probably get to that this weekend.

David
 

TomY

Alden Forum Moderator
Jun 22, 2004
2,758
Alden 38' Challenger yawl Rockport Harbor
Garboard plug installation

My garboard plug is a simpler bronze 2 piece with plug. I didn't install it but it looks quite simple to do. These plugs have a square stud to put a wrench on for removal. The plugs are standard and available anywhere piping is.

I believe a small cordless drill may fit but if not a small right angle drill with a small feeler bit will fit in the sump. Drill a hole about an inch above the bottom-check the garboard plug you intend to use first to see how much flange area is needed. Then drill the required hole from the outside. Bed and install the plug housing.

They are all designed to be removed from the outside. I use pipe sealant and tighten just before launch. They do not come out on their own. Hope this helps, a dry bilge is good for the boat anytime.