I’ve been using borax cones for years, with the fireclay dish that
you grind in. You can make just as much as you want, when you want,
and there no problems with powder getting damp and clumping. I like
it also because it feels like a connection with generations of
silversmiths, and the action of grinding is quite therapeutic.
Err. Just exactly what are we talking about here? Bob is the third or
fourth person I’ve seen talking about powders and ‘pre-prepared
What do you guys think a borax cone and slate are for?
They’re just an old way of making up soldering flux. I have no idea
what anybody would do with powdered borax in regards a soldering
flux, and the ‘pre-prepared’ stuff is otherwise known as–flux.
Nothing fancy. Could be batterns, pripps, or paste flux, all of
which work better than pure borax and spit, which is what you get
from a borax cone. It works, and it’s cheap and indestructible, but
it’s not spectacular or anything. (Yes, I realize that most people
keep boric acid powder around for making fire-coat, but pure borax
wouldn’t do that. I keep powdered borax around for a basic casting
flux, but again, not a soldering flux.) I’ve still got my borax
slate from college days, and I pull it out every blue moon or three,
when a student gets a yen to try it, but then it goes back into the
drawer until the next time.
I bought and used the borax cone and dish when I started making
jewellery. Unfortunately, borax alone does not prevent against
firestain. I changed to mixing my own Prips flux. It works so much
better than borax alone. I ground up my borax cone to use as one of
the Prips ingredients. I now use my dish tocut my solder pallions
into, and that’s where they stay until used. I mixedup a fresh batch
I Prips a couple of weeks ago and it is infinitely superior to the
tired, repeatedly diluted Prips I had mixed up about two years
Why the cone" That is how it was sold over a century and a half ago.
Why in preference to borax powder" well it takes up less space and I
used to keep my cone on a refactory dish and added a few drops of
water, ground the cone into it a bit and whn I had the right
consistency I usedit The remainer dried and stayed where it was. With
powder you have a lerger container to decant the powder from and the
dust gets up your nose, into cuts and eyes and is a pain when it
does. Also, you still have tomix it with water somewhere and then
fiddle about to get the right consistency and when the excess dries
out it is a sod to dissolve/grind downagain without the cone to do it
with. The powdered borax often contains other borates that are added
but the cone used to contain borax as precipitated which although not
pure had a consistency between brands which is not the case with the
others so if you buy say, Agrotect it is different from Auflux etc.
and use the wrong one and you can get firestain. Nick Royall
I am sure that there are very good new and efficient fluxes on the
market. But in my case, almost everything I have ever soldered
during my 52 years career has been fluxed using a borax cone and my
old borax dish. It works, it’s cheap and a borax cone lasts for ages,
so I say to myself why change an old reliable method that works fine
I have no idea what anybody would do with powdered borax in regards
a soldering flux,
I use powdered borax as one of the ingredients when making Prips
flux. I’m certainly not going to buy the commercially available
version of Prips as it’s so expensive! The first time I made it, I
crushed up my borax cone in a pestle and mortar as I knew I would
not be using it again in cone form. UnlessI am wrong, Prips works as
a good firecoat but can also be used as a soldering flux. It works
I buy all ingredients necessary for making Prips (borax, boric acid
and trisodium phosphate) from suppliers selling via the auction site
whose name shall not be mentioned. Lab grade chemicals are available
inexpensively from many suppliers on the auction site.
I’ve always used a borax cone (~40 years). You don’t need any
special plate: just a flat piece of matte (sandblasted) glass. Or a
plain old piece of marble (it gets slightly concave over time, like
a plate). And a little bottle of distilled water. A few drops of
water, and a circular motion of the cone on the glass/marble/slate.
The more circles, the thicker the flux. I like it because you make
the flux as you need it, so it’s always clean, and you can make it
thick or thin. The old ethnic jewelers in Israel all used cones
(except for powdered solder mixed with powdered borax for filigree),
and a pigeon feather for a borax brush. Torches were used with foot
bellows and a can of benzine (petroleum naphtha).
I believe the cone borax has a higher melting point than most (all?)
powdered borax/flux. That was good for me, as I rarely use anything
other than Hard (silver and gold) solder. You might need the
powdered fluxes for Easy silver and gold solders.