I don't know if one method seals better, but I can tell you that the 1.25" washer is supposed to be in front of the 1.5". It helps cushion it from the "cookie cutter" effect that happens when you tighten the finishing washer.
As the title says, I need something that will seal in 2 inch pvc, as the 2 1/4" washer I tried created horrid amounts of friction.I also have to be able to attach it to an up-sized superlative plunger head, if it makes any difference.
Did you lube the PT? That helped immensely on a 1 1/4" PVC PT for me.
Alternatively, try cutting a tiny bit off of the edge of the washer, getting it absolutely perfectly round shouldn't matter if it's still in contact with the PT all over.
Not sure if any of this will work with whatever you're planning on using as your plunger head.
Meaker: Yes, I covered the washer in White Lithium Grease, but it didn't help much. I'll try trimming the washer. Ryan: I would like to try the cup,but how would I attach the cup to the plunger head? Proplus: Are you sure this part would work? Mcmaster says the OD is 2 and 3/8", which is even larger then the washer I used.
The washer I have was 1/8" thick, as my Ace didn't have 1/16". I took another trip to Ace today and got a 1/16" rubber sheet and traced over it. That way I can adjust the ID and OD easily. Thanks for the help everyone!