Under bathroom sink in basement I have a joint that is leaking water, the piping is Iron I think. Is there a quick fix?

Hi Lisa

The answer to your question will depend on exactly where/what is leaking...;) Take a flashlight and see if you can see exactly where the leak is and then tell us if this is a water pipe or a waste pipe. If it is a water pipe you may simply need to tighten a nut or something like that. If the leak is at the waste/drain line you may be able to patch the pipe using a PLUMBER'S EPOXY PUTTY (available at all home improvement stores). Tell us a little more if you can...

Mark

the piping is Iron This leads me to think in might be a black cast iron pipe leaking from a poured joint. Did I guess correct?
We need more information. Describe the leak. Back to you. Tom