I took the upsides of both plunger heads: the PVC catch ramp from Carbon's (I think?) traditional Snap plunger head, and the metal catch face from rork's Superlative plunger head. I'd like to give props to both fellow Snap enthusiasts as the Preeminent plunger head is pretty much a combination of both their designs. Alright, enough jibber jabber, I'll cut to the chase.
-1/2" CPVC endcap (MUST have a flat bottom)
-3/4" PVC endcap (MUST have rounded bottom)
-1.25" OD 3/16" ID Stainless Steel Fender Washer (2)
-1.25" OD 3/16" ID Nylon Washer (can be replaced by another of the above part)
-Nylon spacer of appropriate size
-Long enough #6 bolt
-Seal of choice (skirt, washer, grommet, etc)
Drill a centered 5/8" hole in the 3/4" PVC endcap. Using a pilot hole is helpful for centering as spade bits can be hard to keep steady sometimes. Shave/sand off any writing on the base of the CPVC endcap. You need it smooth. Wrap it in e-tape so that it fits snugly in the PVC endcap.
Goop 'er in like so. Sand the face of the assembly that is shown a bit. Don't go overboard and give it a bad angle.
Super glue on one of the steel washers as shown. Be sure to apply superglue to both the exposed base of the CPVC endcap and the parallel lip of the PVC encap. Center the steel washer as much as possible; it should be a tad smaller than the PVC endcap.
Shave down the lip of the PVC endcap as shown. You want a smooth transition to the metal catch face.
Drill a centered hole for the #6 bolt in the CPVC endcap.
Glue on the nylon spacer. Keep 'er centered (god I'm a broken record).
Glue on the next steel washer.
Now just sandwich your seal of choice between the steel and nylon washers, followed by the finishing washer. Clamp it all down with the #6 bolt and nut.
Okay, now you have a couple of options for methods of fixing your plunger head to the CPVC plunger rod.
1st method: Solvent weld it in your CPVC encap. This puts the stress onto the bolt's threads.
2nd method: Screw in your plunger rod. A much better option in pretty much every way, but it takes more work. I'll probably end up doing the first option because I'm lazy and trust my solvent weld. For the second method, you'll need to create a funnel of sorts for the screw head so it doesn't get caught on the roofing nail catch. You'll also need to cut excess length of the screw so that its smooth with the endcap. The following are pictures of this on a previous plunger head:
And there you go. Enjoy!
Update: Beaver's Revisions
Here's a refinement that does away with the e-tape. You'll need the following fittings:
* Left: 3/4" PVC cap, as in the writeup
* Middle: 1/2" cpcv cap, as in the writeup
* Right: The magic fitting that makes this work. It is a 3/4" male thread to 1/2" couple adapter. The OD of the couple end is the same as the OD of 3/4" PVC, so it fits into the 3/4" cap. It will act as the interface between the other two fittings.
We're only interested in the coupler end of the threaded fitting. Cut off that part with a PVC cutter.
You can then nest all three together (with the persuasion of a hammer).
The end result is perfectly straight, and requires no mucking around with e-tape, nor does it require any fittings to be ground down to fit. I also don't think any adhesive is required, since the fits are so tight.
FYI, I got the adapter fitting at ACE hardware. Not sure what the proper name for it is.
Zorn also suggested using a 1/2"socket-to-3/4"spigot bushing in place of the adapter that Beaver found, as the spigot bushing is more common.
Edited by TantumBull, 14 July 2010 - 01:56 AM.