Any suggestions on how to handle "dingy" solder stains?
work as clean as you can. The problem is simply that solders
are a different color, plus they soak into the surface of the
metal. So anywhere the solder flows, you’ll see that stain.
Can’t prevent that from showing. So you have to prevent the
solder from going where it’s not wanted. First off, you need to
stay with the hardest grades of solder you can manage, for the
best color match, and then be careful to get tight fitting seams,
so the lines are thin, and then use as little solder as you can,
letting capillary action draw the solder into the seam. Place
the solder where the resulting scars at entry points will be
easiest to clean up. If you get sloppy solder somewhere, it’s
only because you put the solder there, or used so much that
excess was allowed to run everywhere. Spend the extra time to set
up the soldering operation, fitting the parts, and working
"tight". It will pay you back twofold in the quality of the
result and reduced cleanup. Remember, also, that since you don’t
need to prevent fire scale on the fine silver, you can help
reduce unwanted solder flow by using a minumun of flux too,
getting it only in the seams. Solder won’t flow so much where
there is no flux.
Hope this helps.