My central Air Conditioner has problem with leaking water on the
floor. After inspection I found the water seems from the conjunction
betweek the plastic water pan and the threaded femal copper pipe
adaptor. The plastic water pan is inside the AC unit inside house.
The threaded femal copper part is for the connection to the drain
system to the outside. Since the gape between the above two mentioned
parts is lower and before outlet of the drain pipe, condensed water
all leaks through the gap to the floor, and not water really go
through to the drain system. I tested the drain pipe to the outside
is not clogged, and water will go through the pipe only when pouring a
lot of water suddenly inside the AC unit and the water level is higher
above the outlet of the drain pipe.

I guess when tightened the male pipe adaptor to the femal copper part,
the toque loose the copper part with built on the water pan, and made
a gap between the water pan and the copper pipe. Now my question is
how to fix it by myself? Is there any seal or glue for this purpose?
I asked the HomeDepot staff, and the J&Bweld was recommened. However,
this product takes about 5-8 hours to cure or dry. I really don't
have that long time to wait in this hot summer in Texas. I read
instructions of other products, like Amazing GOOP Plumbing, AquaMend
(underwater repair epoxy putty stick), and SeamerMater (Professional
grade) for gutter, but I am not sure which one can really do the
work.

Also, it is very hard to access the damaged area. There is no way to
separate the two mentioned part. The only thing I hope is I can use
my finger to put some kind of seal or glue along the conjunction to
stop the leaking.

Of course, the final way is to call an AC specialist to replace the
water pan, which probably will cost me several hundred dollars.

Please give me suggestions?

Thanks
SZ