Through hull fittings?

[otcutshine]

I have had thru hull fittings snap off at the scupper just belwo the 90* bend on three seperate times in two years. I carry wine corks and 3/4 inch caps just for the quick fix to get home. Coincidentally, mechanics had been working in the bilge to pull the manifolds on one occasion and the starboard motor on the other. Is this coincidence or not. The fittings are for the raw water intake on port side and the starboard side would be the OB effluent discharge. Both sides have 3/4" 90* bend to 3/4 full port ball valves with Backflow preventors to hose bibs. I was thinking of replacing the scuppers and using closed cell foam supports to take the load off the scupper stand pipes. Anybody have this problem? Also, what hose do you use on the live well to Macerator discharge? I was thinking of plumbing this with a QD to allow for removal of the cooler for maintence to the bilge. Any thoughts.

1995 28'JS w/ mercruiser 454's that I love to hear sing!

[otcutshine]

Raw water intake for the washdown pump!!!!!!!!!

Washdown pump intake not motor intake . Sorry for tyhe confusion. Mark

[Split Decision]

I would think not a coincidence. They were most likely steped on when they were working . I assume not much room. What actually broke? The casting or the threaded nipple. They can split in the threaded part of the nipple. Especially if they were brass instead of bronze.

[otcutshine]

Break

They broke in the threaded part of the cast fitting. Make sense? Always just above the top of the retainer nut. The screws of the strainer screwed into the outside of the hull keep the scupper in place so the retainer nut can be removed and a cap/ washer can be reinstalled to make the repair restrained and water tight.The wine corks have been known to last a 38 mile run in 3-4 seas. Luckily, through someone elses forethought, I have learned to grease this nut before assembling for future issues. There does not appear to be any corrosion issues as the break appears jagged but clean. Being jagged is making me suspect a point load situation caused the fatigue. Whether a misplaced foot as you suggest or a severe pounding in rough weather compounded by the heavy profile of the self supporting fitting arrangement between the 90* bend and the rubber hose remains to be seen. I will pull the boat in the next few weeks and affect repairs. Thank god for winos who are pack rats or I would be up a creek. Thank You for your input. Respectfully, Mark J

[TwinFin]

scary

This is scary. Just had my starboard trans replaced so the engine had to be slid around on the mounts. They must have crawled in there to push the engine back into place. No evidence anyone stepped on that thru hull but one battery switch literally fell apart in my hand the morning after I go the boat back - likely due to some sort of accidental abuse during the repair.

Where were you when the raw water thru-hull snapped off? If this happened while the engines were running I can't imagine what a bitch it must have been to get in there to cork the opening. Or did you dive under the boat? If you were slipped when it broke, how much water got in before you realized there was a problem? Did your bilge pumps cover the leak?

I'm a bit confused about your references to strainers and scuppers here. My raw water pick up (valve located fwd of port engine) is a 90 degree thru hull with no strainer - just a simple thru hull open under the boat. Not sure what you mean by a scupper here??

[otcutshine]

Thru Hull

The first time the fitting broke on the starboard side I was 38 miles out chunking. Immediately called the local boats around me, made temp repairs, called the coast guard letting them know I may need assistance and started to run home slowly. As I gained confidence in the repair we ended up at cruise speed. The second time it broke I was running south along the beach for 30 miles coming from a shark weighin in OC MD to Chincoteague Va. Due to heavy weather and a big head sea the fitting only leaked marginally when the boat was running due to plane attitiude. Once I had to slow down to make the shallow water run into my harbor the water ran full bore. I Knew I had snapped this fitting but the aft bilge could keep up easily and thunder and lightning was coming. Got into the slip and made five minute temp repair. Lot easier when you you have the needed items at hand. Next time I was fueling the day after a hard tournament run. The bilge would periodically fire off for no reason. Once fueled, went into bilge and found port fitting ruptured but 1/2 broken. Quick five minute repair and I'm O'K. Fittings go to raw water washdown and overboard discharge. No biggie, fresh water tank and five gallon bucket are adequate substitution.
The water comes in equivelant to a hose bib at half pressure. I have taken to carrying the following items for the quick fixes. Wine corks, tappered wooden plug, 3/4" close nipple, 3/4" coupling, 3/4"Cap,Pipe wrenches, teflon tape, thread seal, 3/4" fender washers. I am leaning towards the mechanic using the fitting as a brace for leverage. Still, half the time I am the meachanic. I will be supporting the fittings with closed cell foam as wedges for added support.
Mark aka Retriever