Sulfated battery

I recently acquired a bike with a fairly heavy sulfated battery. I promptly removed it cleaned up the tray, fittings etc... and installed new battery.

For some unknow reason I decided to see if I could bring the bad battery back to life. I cleaned it up, topped it off and hooked up the tender. It reached full charge in about 24 hrs. I rotate various batteries with this tender and it wound up back on this BAD battery. It's been hooked up for about two weeks and I just noticed it.

The #%^&*$ thing has sulfated at the negative terminal and eaten the spring clamp for the tender. The clamp is virtually fused to the terminal.
Now I'm %^&*@. I feel like throwing the %^&*$ thing across the garage. (That would be reeeeeal stupid)

I could have sworn I cleaned those terminals. Apparently NOT.

So trying so salvage a POS battery, I have damaged a piece of equipment. Oh I can fix it alright, but it's the point.

What is the point anyway? I'm not really sure but I do feel better talking about it.
I know someone will understand.

I know it won't help, but I symapthize.

Who among us hasn't sent good money chasing after bad? I'd hate to itemize the numerous expensive bits I've fragged over the years.

... hoping you haven't done any permanent harm ...
David