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where to start looking for a leak?
Posted: Tue Feb 12, 2013 1:54 pm
by cavi
I have a 1984 mac 22, and since the rainy season has started I keep finding water in it. after a large storm i will pull about 1 to 2 buckets out of it. It looks like it is accumulating in a sort of valley that runs across the boatright behind the door to the cabin, this "valley"has a hole about an inch or so above it and when the water gets to that point it drains into the hull itself. I have tried placing tarps on the deck and covering the door with a tarp. I even put some silicone glue around the hatch that is part of the port side seat.
I am at a loss, I am currently thinking of going out during the next storm and sitting in the boat. Does anyone have an idea where I might look first?
thusfar this is my only complaint about this boat and I would love to solve it!!
Re: where to start looking for a leak?
Posted: Tue Feb 12, 2013 2:40 pm
by RobertB
SMART ASS ANSWER: Look for the leak where the water is coming in
If that does not work, since from your description, the water is behind the companionway (if not the companionway), look for cracks and holes. Do you have a freshwater shower installed near the motor? - I have found a leak on mine there. Are there gaps around the motor? What about the base of the pedestal? One idea, spread a little bit of talcum powder around the edges of the aft compartments and see where water disturbs them.
Re: where to start looking for a leak?
Posted: Tue Feb 12, 2013 3:50 pm
by kmclemore
Drip diluted food coloring at the places you think it may be coming in. Use different colors for different places. See what color shows up below.
Alternatively, sprinkle flour or corn starch on the inner walls of the hull and look for traces where it has been disrupted or wetted. I'd avoid talc as it's not great to breathe the stuff.
(No jokes about fat ladies, please.)
Re: where to start looking for a leak?
Posted: Tue Feb 12, 2013 4:53 pm
by grady
Not sure about your model but I had issues where the upper deck and lower hull is riveted together. Had to seal all around the rub rail on top.
Re: where to start looking for a leak?
Posted: Wed Feb 13, 2013 9:07 am
by cavi
thanks, the corn starch thing seems like a good place to start, and honestly, if i get a rainy weekend in the near future I might just go chill out in the boat!!!
Re: where to start looking for a leak?
Posted: Wed Feb 13, 2013 4:05 pm
by RobertB
kmclemore wrote:Drip diluted food coloring at the places you think it may be coming in. Use different colors for different places. See what color shows up below.
Alternatively, sprinkle flour or corn starch on the inner walls of the hull and look for traces where it has been disrupted or wetted. I'd avoid talc as it's not great to breathe the stuff.
(No jokes about fat ladies, please.)
Ok, nix on the talc - use the wife's perfumed powder - easier to breath

Re: where to start looking for a leak?
Posted: Sun Feb 17, 2013 3:33 pm
by jtis1
I may know where your leak is coming from. I have a 1985 Mac 22 with the same design and had the same issue-it would not leak during time on the water but every rainstorm would bring water inside. That hole that you are describing aft of the companionway in the "valley" is the cockpit drain hole and goes straight through to the keel trunk. Unfortunately, when the seal gets old between the drain passage and the keel trunk a considerable amount spills into the bilge and cabin. You dont have to wait for the next rainstorm. Just take a flashlight (and precoat with the flour too if you like) and have an assistant pour about a quart of water onto the cockpit floor while you are looking. My guess is you will see some leaking out of the seal onto the floor behind the companionway and then into the bilge and cabin. Good luck.
Re: where to start looking for a leak?
Posted: Wed May 29, 2013 6:09 am
by vkmaynard
grady wrote:Not sure about your model but I had issues where the upper deck and lower hull is riveted together. Had to seal all around the rub rail on top.
Bob Menches recommended this fix on our Charleston sail. It worked for us. Massive reduction in water intrusion. After a few weeks of rain I would wet/dry vac up to 15 gals of water. Now after 5” of rain maybe three cups of water.
Victor
Re: where to start looking for a leak?
Posted: Wed May 29, 2013 7:43 am
by K9Kampers
SMARTASS ANSWER #2
I find that when looking for something, it's always in the last place I look, so you should start there first!

Re: where to start looking for a leak?
Posted: Thu May 30, 2013 2:41 am
by Catigale
Number 3
Fill the boat with water and see where it leaks out..