Gasket Material for Oil Canister Leak Issue

This refers to a 140XK : I realize that this topic is frequently discussed and I have tried all suggestions but still have a minor leak at the canister seal interface, both with the original and spin-on adapter. I am curious if a more permanent gasket material can be used in lieu of the o-ring when using the spin-on adapter which does not require removal at oil changes.
Thank you

Is your filter like this?
oil filter 005
Are you using a square cross section o-ring?
There’s not much to this design, so if you have a square o-ring in there, maybe you should look for damage on the sealing surface.

I’ve tried square and X shaped cross sections. My filter is similar but it is the “bolt through bottom” version of the Tecalemit. No number on the head.

So you have this.

Is the top end of the canister flanged or flared out, or is it straight cut like this?

It’s a straight edge canister. The head has an extremely thin opening for the O-ring. I have cleaned the O-ring opening and cannot get any O-ring inserted except for the thinest profile. I do not detect any unevenness on the canister sealing edge.

As an additive note: Both the original Tecalemit and the spin-on adapter are equally messy to change. One issue with the spin-on is that when removing the filter the base tends to loosen and come off with the filter. I do not believe that I am over tightening the filter and I am reluctant to over tighten the base or use a thread locking product on the base to head bolt.

I have it in my notes that the o-ring size is 241.
I’m not familiar with the adapter, but the sealing idea is the same.
Look for damage in the groove?
The head has a steel threaded insert, so you can put a bit of torque on it.

I read a previous post of yours recommending size 241. I bought all types of O-rings from McMaster-Carr in size 241 and others and in all profiles. Either can’t get the O-ring inserted or when I do it leaks slightly. Most O-rings come in quantities of 10 or 25 count. I have so many I’m thinking of opening an O-ring boutique.

Hmm, that would be frustrating. The technology is not all that complicated. Basically you need a really good microfinish at the bottom of the groove and on the contact end of the canister, no radial scratches, and uniform compression all around on the rubber.

Make sure you get all of the old orings cleaned out of the slot. Somehow they had multiplied in mine.