I teach students how to solder and finish pieces neatly without
grinding off excess solder. I always tell everyone if solder doesn’t
flow the first time around heat the piece up and make the solder
flow again. Make sure everything is fluxed well. [ I use white paste
flux] Usually the main reason solder doesn’t flow and leaves lumps is
that the total area was not hot enough. Solder likes to flow into
areas that are touching and clean. It follows the flame to the place
where it is hottest. It depends on capillary action. If the joint
looks dirty, pickle the piece and scratch the solder and area where
it is supposed to flow carefully with a sharp pointed object to make
sure it is clean. Do not grind off anything! Let the heat pull the
solder where you need it. Use the blue tip like a pencil point to
direct the flow.
I have a feeling you may need to practice soldering and get familiar
with the color changes that solder goes through when you are melting
it and also the color that the parent metal should be when solder
flows. If you practice on scrap metal and get used to having it work
and being in control by melting solder and then going in and
re-melting it you will gain confidence and be able to go back and
fix anything you are making. I hold my torch in my left hand and
tweezers in my right hand just incase I have to make adjustments. The
key is practice and good work habits! Do not grind! Tumble polish and
definitely resist the temptation to go in and sand, file or grind!
It will just make a mess and take 10 times longer!!!