May I polish before soldering?

Hello Tina,

I’m butting in here - but my impression is there is no critically
exact recipe. What I have done is to get a jar of alcohol and add a
spoon or two of boric acid, shake it up until the boric acid
dissolves, add a little more b. a. and shake some more etc until you
can’t dissolve any more. If there are still some boric acid
particles in the bottom of the jar, no matter how hard and long you
stir or shake the jar, then you’ve got it. This is now a saturated
solution. The alcohol just serves as a sort of vehicle.

Now “soaking” your work in that solution is not exactly what you
want to do. The basic process is to dip your workpiece into the
solution and then remove it to a safe, clean, fireproof surface (of
which see more below) and touch a flame to the piece. The alcohol
will ignite and burn off in a few seconds, leaving a thin white-ish
coating of boric acid on the work. You should repeat this procedure
a number of times to build up the thickness of the coat with each
repetition and thus insure that every surface is well coated.
Because you have started by making a saturated solution, the coats
previously deposited cannot re-dissolve back into the solution when
you re-dip the piece because the solution is already at its limit.
However, because you are wetting the powdery coating it may appear
to be gone, but it will still be there, so don’t worry.

Now - this is VERY important and i apologize if you already know it.
Alcohol burns with a flame which is almost invisible. This makes it
very dangerous because it is possible to set your surroundings and
yourself on fire and not even notice what is happening until you
actually feel the pain or see other objects starting to burn. So -
to start with - have no open flame nearby when you start. Be very
careful about any drips or splatters when dipping or moving your
work piece from the jar to the work surface. Second, have a cover
for the jar and replace it every single time when you remove the
workpiece and before you bring a flame anywhere near. The alcohol
vapours are flammable and you don’t need to touch a flame to the
liquid to set it afire. You need only bring a flame near to the open
jar and that may ignite the vapours and the flame will then jump
down to the liquid. So be a bit fanatic about this procedure. So you
dip, then remove work, then cover jar, then place work on a safe
spot to set it afire. Make certain you haven’t dripped alcohol onto
your clothing, that your hands are not wet with it, that there is no
alcohol dripping or running off the piece to make any small puddles.
A good set-up would be to set the workpiece on a small, raised
screen over a surface which cannot be ignited or harmed by any
dripping alcohol, maybe even over a shallow dish of water which can
absorb and extinguish any flaming drips once you ignite the piece.
When you are ready to re-dip for each subsequent coat - make
absolutely certain that the flame on your workpiece has gone out
before re-opening the jar and re-dipping. Also, in your handling of
the piece, make sure the tool you are using to move it: tongs,
tweezers, wire hook or whatever you use, is set aside safely out of
the way before you set the piece aflame so the tool does not catch
fire and inadvertently transfer flame where you don’t want it to go.

This was many more words than necessary - and i hope it doesn’t make
the process sound patronizing or excessively complicated. It is not.
it is simple, easy, quick and safe if you are just very careful
about flame and alcohol. It is very very distressing to be involved
with an alcohol fire on your clothing or skin because you can’t even
see where to beat at the flames to extinguish them.

Enjoy.

Marty in Victoria where I play some of the best Irish music with some of
the best Irish musicians this side of Dublin.

Hi Tina,

Maybe sandblasting? There exist all kinds of setups not just for
large work but also miniature work as well.

Might be worth looking up or rigging on your own.

Andrew Jonathan Fine

Very funny John! How hideous are they?! I had something a tad more
sophisticated in mind. I like mid level to expensive shoes and would
love to have a go at designing and making quality shoes, made with
quality leather. Funnily enough, I had a bit of a sort out last
night, and my daughter got me to put all my shoes on my bed so we
could count them. Apparently, I have 31 pairs ofshoes/boots! I’m
sure other ladies can beat that score. I managed to find five pairs
that I could live without, which will go for the homeless, so I
only(!) have 26 pairs now. Mind you, there’ll be a couple of smartly
shod homeless folk!

Helen
UK

Hi Tina!

Is there a product I could buy on the market that would do the
same? I guess I am looking for an easy solution.... 
Janet, what is the exact recipe for your suggested remedy.
  1. You can get the solution ready-made at any jewelers’ supplies
    store. I believe it would be called just that: Boric acid solution.
    At least that’s what it’s called in my part of the world…:-)…
    It’s usually purple or blue.

  2. You can simply buy denatured alcohol and boric acid granules at
    any pharmacy (although it’s much cheaper at a chemical supply
    store). Put some alcohol in a small container that has a VERY
    tight-fitting top (it evaporates very easily), and gradually add the
    boric acid granules, stir well till dissolved. Keep adding granules
    until they no longer dissolve (at which point it is
    super-saturated). I keep it in one of those old black plastic film
    containers with a snap-on top. When I need it for something bigger,
    I simply brush it on.

Janet in Jerusalem

Hello all,

I use LAB-GRADE boric acid powder (it’s extra fine and pure) and 99%
isopropyl alcohol mixed to a heavy cream consistency. Actual mix
isn’t critical asfar as I can tell. I’ve been using this for over 30
years. I have annealed many times when making hollowware and not had
any fire scale. It is an excellent flux so there is no need to use an
additional product. I do use flux when using very hard solder just
for insurance. The mixture seems to fail only when I overheat when
hard soldering. You buy both from scientific supply houses.

Karen

Thanks Andrew,

Maybe sandblasting? There exist all kinds of setups not just for
large work but also miniature work as well. 

But I do not think I am equipped to use this technique.

If its difficult to see the nooks and crannies it would imagine it
to be impossible to sandblast them.

Thanks for taking the time
Best wishes
Tina

Argotect specifically made by Johnson Matthey for this job.
Available in 500 gm pots. Certainly available here in the UK in
the Jewellery quarter in B'ham, and most probably in Ireland as
well. 

Thanks Ted, I travel to Birmingham quite a bit so, i should be able
to pick it up.

Thank you so much!