multiple thru hull's leaking

[dgill]

At relaunch last week of my 1987 C-34, three of the six thru-hulls leaked at their hull/thru hull connection.  The leaking was a steady, but small stream of water, that unfortunately did not reveal itself until after I was out of the slings and in my slip.  I took the boat back to the marina.  One additional thru hull showed signs of leaking after the boat was hauled out--on the bottom of the hull the mushroom thru hull had a visible circle outline which was never there before.

I will have all six thru hulls rebed.  My boat was stored, on the hard, all winter.  I thought I would mention this to alert owners of other older C-34's to think about this task as a maintenance item.  The bedding apparently failed after nearly twenty years-not surprising.  The good news is that I was present to discover this!      

[Jeff Kaplan]

thanks for the heads up. last year when i launched #219, i noticed water seeping in from the raw water engine thru hull. i put a wrench on it, tightened a half turn, and stopped leak. i will check all before this years launch....jeff

[Ken Heyman]

Thanks for the alert.
My boat is currently on the hard. I will inspect the thru hulls. I wonder if the real acid test might be to get some water inside the boat and see what leaks out. What do you guys think?

Best,

Ken

[Ken Heyman]

-------------on second thought maybe taking a hose under the boat and inundating the respective thru hulls will apply sufficient pressure to ascertain if there is a leak?

Ken

[Ron Hill]

Denise : Sure is strange that three of the six recessed factory thru hulls all decided to leak at the same time.  The "mushroom" thru hull must be either your depth or speed transducer - not surprising that it may have sprung a small leak.

If the thru hull is intact(not cracked), you can clean the underside recess between the thru hull and the hull.  Then force some caulk in that fine line.  Just remember to paint that caulk.

Almost sounds as though the thru hulls were not torqued down by the factory.  If any liquid were in the line and it froze, it would have probably damaged the ball valve (On/Off) on top of the thru hull. 

Each year I closely check the transducers and insure that there's a solid bead of caulk on the lip that joins the hull.  Most of these transducers have a thin piece of plywood on the inside to help flatten the contour and swell if there is a small leak. 

You could try to tighten the thru hull nut from the inside, but I think that you might do more damage to the existing caulk and definitely break the paint at the hull/thru hull joint.  Better to remove the hose and the thru hull and start all over.

If you had a hard operating thru hull and "women handled it" that may have been the cause?!  Glad you caught it in time.
Still strange !     

[dgill]

The speed and depth transducer thru hulls were not the problem.  The ball valves are all ok - they were not the problem.  All of the six thru hulls were winterized - so freezing was not the problem.  The issue was that the thru hull bedding on the head sink, galley sink and macerator had reached the end of it's useful life and no longer provided a seal.  I did stem some of the in flow of water by tightening the Marelon nut, but realized quickly that this was not a "fix".  I decided to replace all six of the thru hulls - the cost of this is cheap insurance relative to a failure down the line when it is not convenient.  As you can imagine, removing the thru hull without any damage is not always possible.  Defender sells these for about nine dollars each so renewing them is a no brainer.  When the boat gets back into the water I anticipate that this will never be an issue for me as this fix should out live my ownership of this vessel.   

[Ron Hill]

Denise : You did the correct thing by replacing all of the thru hulls.
BTW, thru hulls that are left open during long storage on the hard (which they should be), are "winterized". 
A great "heads up" .  Still strange that 3 decided to leak this year??  

[Ron Hill]

I knew something was bothering me and I believe I've finally figured it out. 
The previous owners prided themselves with leaving the boat in the water all year long, with a short haul in the spring to clean the bottom/running gear, repaint and then splash.  That worked OK while the boat was in NC for 5? seasons, but the creeks off of the Chesapeake Bay, freeze over most winters. 
I know of NO way to "winterize" a thru hull while the boat's in the water?!? You can pour antifreeze in the line which helps the ball valve, but how do you get it to stay in the short stem of the thru hull between the hull and the ball valve??? - You DON'T.

I believe it's a BackYardBoats-ism that "the caulk reached the end of it's useful life".  I'll bet that you had freeze damage that finally showed up!!  I've change out a number of items on my boat (one year later in production) and I've had one "hell of a time" breaking thru the still very flexible caulk.

You are one lucky Captain to have them all leak at the same time and be observant enough to catch the leaks before more damage could have been done.   
A few thoughts.   

[dgill]

For five seasons of my ownership of this boat, it has not been in the water during any freeze period.  As far as I know, during it's prior ownership, there were no instances when it was in waters that were frozen.

As you correctly point out I am very lucky to have caught this and avoided bigger problems.

[Ron Hill]

You have pulled the boat during the off season, but the PO did NOT pull your boat out of the water during the winter - that I  know!!  OUT