macerator to rv dump

S

slowtrot

New member
I have a 25 CD and I wanted to be able to not only have the holding tank pumped out at a marina, but wanted to be able to dump at my house or at an rv dump station. And I did not want to take a poo shower trying to hold up a compression hose.

I could not find a hull thru fitting with 3/4 tapered pipe threads. The standard fitting on the boat looks to thin to me to simply run a pipe tap into it.


So, I bought a pvc 1/2" female tapered thread to 3/4 bushing and turned it on my wood lathe to a slightly smaller external diameter than the standard thru hull waste fitting on the boat. I filed off the anti spin ears in the standard thru fitting and roughed it up with sandpaper. I then used JB weld to glue the pvc 1/2 bushing flush nto the boat fitting.

Now I have 1/2 threads inside the standard discharge fitting and I screw in a short 1/2 nipple clamped to a clear hose and can pump away with the macerator pump. The hose is stored on the trailer inside of one of the square tubes.

No runs , no drips, no errors, and since I had a hose, the solution only costs me a dollar.
 
I bought the pvc plastic bushing at Home Dbgepot. ( 438-101HC 3/4" X1/2" flush bushing SPIGx RFPT.) I think this translates as a slip fitting for the internal application with glue to the inside of a pvc 3/4" pipe with female 1/2" recessed tapered pipe threads on the inside.

The bushing is round for most of its length but it has 8 flats at one end so that it can be held with a wrench when a pipe is installed. The flats need to be sanded off and the diameter of the fitting reduced so that it can be inserted into the standard thru hull waste discharge fitting. I turned down mine on a wood lathe but you could sand or file it by hand.

Then file off the anti turn pieces in the thru hull fitting, rough the internal surface of it so that the glue has a bite and glue in the bushing. Make sure the right end faces outside!

Now you will have 1/2" female threads in the standard fitting. You can screw in a pipe nipple and clamp a hose on it.

hope this helps
 
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