View Full Version : Boston Whaler Brass Drain Tube Substitute in PVC

11-13-2016, 11:53 AM
On a 1968 Boston Whaler 16'7" blue deck hull, I'm replacing a leaking brass tube main drain and wanted to use PVC instead and went with a 3/4" Sch 40 PVC pipe with a Lasco brand round PVC bushing 3/4" x 1 1/4" from the local Lowes (see 1st picture) at both ends and all sealed with 3M 4000. What I did was cut off the 1 1/4" side of the bushing and used the 3/4" Side (2nd & 3rd picture), see the entire assembly in the 4th picture. Of course the PVC is glued with PVC adhesive, I use Oatey Clear Heavy Duty PVC Cement.


11-13-2016, 12:03 PM
I could have cut the bushing narrower, to just leave a ring at the end to seal, however, I left it thicker because that is where the drain plug will expand and I wanted some more strength there over and above the thin Sch 40 pipe. The drain plug on the Whaler is placed on the inside, so one can drain the boat while underway. Here's the type of plug (don't ever use this type on the outboard side of the drain!).


11-13-2016, 01:37 PM
In the pictures above, the pieces are not yet cemented together. When they are cemented, the pipe will be flush with the bushing end.

11-13-2016, 09:00 PM
well done and noted

11-16-2016, 07:31 AM

The PVC pipe must be thin wall PVC, it is used for lower pressure work, it is 200 psi pipe. It is called Class 200 SDR 21 IPS, Thin Wall PVC Rigid Pipe, which like I said is rated to 200PSI and is standard .93" I.D, 1.05 O.D. (Schedule 40, 3/4" pipe is rated at 480 psi and is a thicker wall pipe that reduces the I.D. to .82", and will not work with the Boston Whaler snap plug, which is at maximum expansion snapped down .94 O.D. The snap plug is adjustable down in size, and will fit the Class 200 SDR 21 pipe, thin wall pipe.)