I've recently begun building a Gott Cooler mashing system. My plan is
to replace the spigot with a tank adapter (of the apropriate material,
thanks Cole-Parmer), build a slotted copper manifold for the drain, and
use an external ball valve for flow control.
The problem I've run into involves soldering the copper. I used SN96
(lead free) and solder flux of the appropriate type for that solder.
When I finished soldering there seems to be a significant amount of
flux residue on the pipe. From this, I conclude that there's a similar
quantity inside the pipe also. I don't want this stuff in my mash system.
The can-o-flux says it contains some stuff that you wouldn't want to eat.
I don't have the names of the chemicals, but I'll get them if someone wants
to know. The can does say "Do NOT eat". That's good enough for me.
How do I get the Flux residue off the pipes?
I did a trial run to see if it's a problem:
I made a test piece soldered with the flux.
I boiled it in an acidified water solution for 15 minutes (lactic acid,
Ph=~5.0) to simulate a wort boil. When finished the solder and
the clean copper looked clean and shiney, but the flux residue
area looked black.
I repeated the test, but cleaned the fluxed area
with a solvent (carburator cleaner...I know that's not good stuff either)
followed by an *** rinse and a good cleaning with soap and water.
This resulted in less black stuff, but still enough to concern me.
Am I seeing an oxidation of the residue? Is there some caustic I can clean
these parts with to remove the flux? Or should I trash this Idea and use
non-soldered parts in my system (I'd prefer to solder few of them, at least).
Any and all help will be appreciated.
Thanks in advance