Replacing 1" discharge seacock with 1.5"

[foursailing]

I'm in the process of installing a Raritan Lectra/san.  One of the problems is the discharge outlet from the Lectra/san is 1.5" - I was planning on using the existing discharge seacock (now connected to mercerator pump) - but it's only 1".  I spoke to raritan and they recommended installing a 1.5".  Can anyone provide any tips for doing this - removing the old and insalling the new?  Is the hull cored below the waterline?

Thanks,

Bill

[Ken Krawford]

Bill,
Your best bet is to get a bung or tapered wood plug that is slightly over 1" diameter at its largest end and drive it into the existing thru hull from outside the hull.  This will allow you to seat the pilot bit of your hole saw and make a clean cut.  Hopefully the flange that is on you old thru hull is smaller than 1 1/2" and that way you can remove the old thru hull and have the proper size hole for your new one all in 1 operation.

[Ron Hill]

Bill : To answer your question - the hull is NOT cored below the water line (only the deck up). 
You'll need a short haul and remove the old 1" thru hull and install the larger one.   

[Craig Illman]

Ron - Just to clarify, you said the hull wasn't cored below the waterline. What about between the rubrail and waterline? I need to install a diesel heater exhaust fitting and they recommend a triple-wall fitting for cored fiberglas.

Craig

[waterdog]

On an '88, 4" below the rubrail on the transom, it's solid.  I know because I drilled a hole for my exhaust there...

[Ron Hill]

Craig : There is no core from the "rub rail" down to the keel attachment.