I just had an interesting experience. While running a NMEA2k network I bumped my through hull fitting from the bilge pump which promptly snapped off. Inspection showed the plastic, I'm assuming nylon, to be brittle. There is no way in this world that I want any through hull fitting to deteriorate. Its simply a ticking time bomb. I also have similar fitting below the water line for livewell intake and drain. My intent is to carefully cork them wet with 4200 until later when I can have the holes plugged with an aluminum patch. I did not see any signs of deterioration on them but why take chances? I would rather install a different pump that pulls up above the water line than have anything that could sink the boat.
The root question: Is Marelon or other plastic fittings going to be as strong 10 years later? I need something that will be as good going forward as the day its installed. How about Stainless with Tef-gel? I have been using the tef-gel and rubber washers / gaskets on all of my other connections. I did not find much with a search here. If I find something on Google I'll update but would sure appreciate anyones experience.
My big concern is galvanic or crevice corrosion given the salty use of the boat. I tend to go 50 plus miles offshore with the boat and failure is deadly.
My big concern is galvanic or crevice corrosion given the salty use of the boat. I tend to go 50 plus miles offshore with the boat and failure is deadly.
Shouldn't be an issue as long as you separate them. You can put rubber gasket material between the 2 metals. Also your paint should help prevent corrosion. Stainless and aluminum are pretty close on the galvanic chart so it might not be a problem at all.
Jason
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Jason
1970 Starcraft Chieftain V
Use Marelon fittings. They'll easily get you another 10 years of use.
You could use Stainless but too many hassles with dissimilar materials and you can't use stainless below the water line in SW due to problems with crevice corrosion. Anything below the water line should be Bronze.
FWIW: My thru hulls are stainless and my intakes are bronze.
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Grady White Seafarer
200 Evinrude Ocean Pro
Through hull fittings on an aluminum boat.
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