T i m wrote
Rod Speed wrote
T i m wrote
Rod Speed wrote
T i m wrote

If the rubber had a thread that matched the waste
outlet at rest, then you compressed it 50% of it's
original size, what pitch would the thread be then.

The compression doesn't happen that way, it sees the rubber
compressed into the metal thread and that is what seals it.

But I'm told there is a thread inside the rubber?

Because that gets more rubber into the metal thread
because the threads match.

R i g h t ....

F r a i d s o ....

but, if you compress something rubber that's
threaded ... what happens to the thread pitch ... ?

Nothing, because the compression is of the
rubber thread into the metal thread, not in the
other direction where it affects the thread pitch.

Now, it's quite possible that any thread on the rubber
could be designed to match the thread on the waste
when the rubber is compressed to some typical value
but if you have ever tried 'pushing' (rather than screwing)
a thread into place, especially when the other half of the
joint is metal and sharp, the 'threads' may not actually
drop into place (potentially making the seal worse).

Even sillier and more pig ignorant than you usually manage.

And doesn't explain why so many found that it
sealed fine without the use of any sealant at all.

Nice theory, pity about the real world.

I wonder how we ever coped?

By using the much cruder approach of a sealant of some form or other.

Quite ... but it worked

Doing it the other way works much better.

I'm not sure there is a better on 'working fine'. ;-)

Corse there is when you don't have to fart around with any
sealant at all, just assemble it and find that it seals fine.