Tub drain clogged; tried all the tips I could find

Hi
I've got a tub on the second floor of a 40 year old house (we bought in 2008).

The tub is *very* slow to empty. I've tried the following with no improvement:
1. Plunging with overflow cap removed and second plunger applied there.
2. Snaking down through overflow cap opening--I got over 12 feet of snake in and it came back out with not so much as a hair on it.
3. Shop vac--vacuum applied at drain with hand applied on and off to overflow opening.

I've poured water from a watering can into the overflow and it backs right up into the tub.

The sinks in the same bathroom empty fine and there are no issues with the second bathroom upstairs.

Is there anything else I can try? If I called a plumber what would he probably do?

Thanks very much
--tom

If you called me to fix it, I would use a power snake through the overflow to clear the clog.

The one I have that I would use on your particular clog has 75' of cable, more than enough to reach any normal clog. It also has interchangeable cutter heads so that I could tailor the head to the specific situation.

It sounds like you should get in contact with a plumber. A automatic snake will probably due the trick, but that is best left to a professional.

Where do you get a automatic snake? It sounds like I have been doing it the hard way for all these years.

John