An old drainpipe 1' off the ground can be used for my washing machine drain. Connections are excellent,with no leaks when I expose the drain to a slopsink of water. At 2/3rds of the draining,air bubbles come first, then steady leakage emanates from the base of the drain,which looks like a nipple of Galvanized in concrete. The last person had a rubbery silicone substance kluged around this area, which I scraped up to observe the leak proper. HELP ME?

It flows for a while and then fills up and leaks at the floor. Correct? Would indicate a partially plugged drain that is backing up. Leak may indicate a hole in the pipe or a leaking fitting. First I would get the drain flowing, have it cleaned out. Then you need to find the leak. You may have to chip out the floor or possibly sleeve the pipe by using a PVC sleeve and epoxy or silicone. You'll need to do some sluething for the leak.

Can you snap a photo of this and post it ?

Personally, I don't believe in epoxy repairs. It is easy to cut off piece of leaking pipe and replace it with new piece. If you post the pic, I will tell you exactly what to do.

Back to you. Milo