leaking shower valve - fixed?

wombosi

hey there folks,
i have a new bathroom all roughed in.
all the plumbing is still exposed and today i noticed a small drip coming from the top of the shower valve (delta) where the vertical copper pipe to the showerhead enters the valve.

i shut off the water supply and drain all the water out. i reheated the joint and was able to melt some more solder into it.

water is back on and there are NO leaks. there is a huge mound of solder around the joint, on top of what i already thought was a full joint.

anyway, i'm just concerned that i put the durock up, tile it, and will never know if that sucker is a good joint and might open up again.

PS - i had a ball valve leaking today too. i've probably sweated 500 feet of domestic supply and hydronic lines with all kinds and sizes of fittings, both sweated and threaded. i've NEVER had one solder joint leak on regular copper to copper joints, but i've had probably 3 valve joints leak.

anyway, after unsuccessfully trying to reheat and melt more into it, i chopped it out and replaced with a threaded valve.
i will probably never use another sweated valve.

but anyway, is my shower valve going to be OK? should i drain the lines and try to melt more in?
taking it apart at this point would be a huge mess. it's holding now, but the ball valve was holding initially, too...

thanks a lot.