Holding tank to bilge leak?

[liin]

Dean:

I took close look at my holding tank last night. I think mine is leaking at forward edges into bilge and/or right at drain plug area. Did you use sponge on stick to get the last bit of liquid out of the tank or some other method? Getting the the forward inside join "V" clean enough at the forward edge to have the thickened epoxy stick is going to be difficult at best. Not sure how you would ever maneuver FRP mat/glass into position without cutting off top of tank. Your pictures were great (thanks) but how did you get the brush into the tank? Or did you? Your drill with wire brush similarly doesn't look long enough to reach bottom of tank. Did you use this in that area or some other device? Getting light, tools and a set of eyes through this small opening is going to be very difficult. The inspection port is 4 inches in diameter at best. Any further suggestions appreciated because I'm right there with you. Thanks Damon

[Dean Abramson]

Damon,

I really inspected things closely today myself, and I now think that, unless you have a big crack on the bottom like I did (which you can pour epoxy into), we are very limited in what we can do on the holding tank (HT) side. I am going to direct all of my efforts now to the bilge.

This is why. Even though my photos make the bulkhead look like a straight-across bulkhead, it's really not. I got a much better mirror in there today. The bulkhead is actually (and somewhat appropriately?) shaped kind of like a urinal, facing forward; the hypothetical guy peeing would be standing in the bilge, facing aft. If you look at the bulkhead on the bilge side, you will notice that just forward of it on each side, and at the bottom, there is a bulge. These are the sides and bottom of the "urinal." In other words, the bulkhead looks like a U if viewed from above, and an L if looked at from the starboard side. It is curved.

Therefore, what looks like a seam in my photos in the HT, is really a pretty big gap, as the piece curves forward before contacting the hull. The wide angle lens makes it look much smaller. You could never get enough filler up in there. All glassing-in by Cape Dory seems to have been done on the bilge side only.

I used the wire brush on the drill in the bilge: and I hose-clamped it and the drill-bit-extension to a dowel to get into the HT, where all I could do was scrub with it. The I wiped with acetone, then did the epoxy steps I outlined. Just get a clip light, remove the clip and refector, and hang just the socket and a 150W bulb in there. Gives you a whole new perspective. Get a good mirror, the biggest that will fit. If you have a small digi camera (or camera phone) stick it in there and shoot all around; when you look at the pix on a computer, it's a lot easier to take stock of things. I pumped out most water with a "Thirsty-Mate" hand pump, then vacuumed the rest with a shop vac. Then, with the bulb hanging in there for heat, I also directed a hair dryer into the space and let it run for about an hour. Have lots of dowels, broomsticks and hose clamps. Making the tools is half the fun! :-(

Now I am going to try to really prep the bilge side as best I can, particularly in the corners where the athwartship plane meets the fore-to-aft planes. That is where my leak is. I will use a grinding stone on the drill extender, and the wire brush thing. May even try to strap my palm sander to a broom stick. Compared to the HT, the bilge is a picnic to work in. I am now thinking of maybe using some glass; not sure. I think I would like to epoxy until I stop the leak, then reinforce with glass. I am cautiously optimisitic about the whole deal, but not overly so.

If you want to talk, call me at two oh seven six five five seven three eight six.

Good luck. Buy bleach!

Dean

[Dean Abramson]

I did it!

My latest repairs worked. I filled the holding tank with water and observed the dry bilge over a period of two hours. Not a drop! Not a single solitary drop. I am really happy about this.

I really appreciate everyone's help on this. In particular, the idea of using the vacuum cleaner was key, I think, and I doubt that I ever would have thought of that on my own.

I have added two photos to my project web page at:
http://www.mainephoto.com/folios/moreboatfun/index.html
You can see that the pumps are back in place. Btw, that rope line is what I use to help pull up the electric pump which is mounted on a piece of fiberglass with a piece of lead attached. I am having some tech issues; please tell me if the web pages download slowly for you too.

Having seen the results of my last dyed-water test, I decided to pretty much epoxy the whole bulkhead, concentrating in the corner areas. I put the vacuum cleaner tube into the holding tank, and stuffed rags tightly around the opening to get a good seal. Then with the vacuum going, I painted pure catalyzed resin pretty much all the way to the top of the bulkhead, both on the athwartship surface, but also on the bulges that are runing fore-and aft on the sides. I had put a lot time into prepping, mainly with the wire brush on the drill, and I had gotten rid of some loose stuff (cracked gelgoat). There were a couple of cracks I could see: one where the dyed water had come from before, and another one higher up in that same corner. When I was painting the epoxy on, even above the vacuum's noise, I heard a PFFFFT noise when I went over that one higher-up crack, and I could see the resin being sucked in. In fact, after a few seconds the crack would open up again, as the vacuum pressure was too great, and it apparently was sucking the resin all the way through. So I loosened the rags a bit, to ease the pressure; then I could get the resin to go in and then stop flowing. After I painted, I turned off the vacuum.

I let that set up for a couple of hours. Then I thickened a lot of catalyzed resin with colloidal silica; got it to the consistency of pretty thick ketchup. This enabled me to put it on pretty thick and have it still adhere to the vertical surfaces. I used the lessened vacuum pressure again as I applied it. As you can see in the photos, I went up quite high, but really went heavy in the corner on the starboard side (left in photos). As it started to set up and got even gloppier, I took a paint-mixing stick and kind of troweled it into the corner. About halfway through this round, I removed the vacuum pressure to make sure all was static and could set up right.

Then I waited two days, then tested again. I was not expecting 100% success; I was resigned to maybe living with a tiny bit of seepage. So I was thrilled when the bilge stayed bone dry! Hopefully, the stresses of sailing the boat will not open things up, but the colloidal silica adds a lot of strength, they tell me.

I was very discouraged when the previous test had failed, and I almost threw in the towel, so I am very glad I took another run at it.

It was a very awkward job, but I have done worse boat jobs. Lying on the cabin sole beats the heck out of curling up in the space behind the engine, where I have spent a lot of time during wiring projects. All in all, I probably spent 4-5 days on this.

I encourage others to check for holding tank leaks, and if necessary, attack this beast. Life is too short to have a cesspool in your living room. Bilges should not stink THAT bad!

What I did is no work of art. But the bilge didn't exactly look like Meg Ryan before I started.

Dean

[Len]

just reading your saga makes me tired not to mention sympathetic to your plight. You certainly take your projects very seriously.I tire easily and give up. But the boat -MINKE- hopefully will be in the water by memorial day. You need to go sailing.If you'd like to take a sailing break from bilge repair let me know.
Lenny

[Dean Abramson]

Len,

If you had smelled my bilge on a bad day, you would have taken it seriously too! But you are right: I need to go sailing. Bad. I hope to be launched witin a few days of you. See you out there. I appreciate the invite, though.

I decided to chronicle this thing as I did because the number of hits on this thread made me think there are more than a few odiferous bilges out there. I have gotten so much from this Board, and I thought maybe others could benefit from my experience. It is inherently not a pleasant project, but maybe someone else would be willing to attack it IF they saw someone else was successful.

Smell on! I mean, sail on!

Dean