Borax Cone

Jewelry Discussion
1

Hello -

Does anyone have experience - or prefer using the borax cone for
flux? How does it hold up during soldering for different purposes and
with different metals? Once ground/dissolved for use, does it store
well and rehydrate easily in small quantities for daily use?

It seems that the borax cone is a purer solution to be working with
for a flux - since it does not contain fluorides. I have primarily
used Handy flux (in a well ventilated situation) over the years, but
it may be wise to change. I’m sure that fluorides were added for a
practical purpose - but never questioned the difference - since I
always liked working with the Handy flux.

Also, I would imagine that a certain amount of caution should be
taken when handling the borax cone during grinding (from previous
threads on borax toxicity) - but am not sure of the risks vs the
benefits - and how careful one would need to be in handling the cone?
Sometimes the old ways have greater benefit - even if the speed of
convenience of prepared formulas have become popularized. It would
seem that there is less risk of toxicity by breathing the soldering
fumes from the pure borax flux.

Frei and Borel was the only catalog where I was able to find the
borax cone. Haven’t found the borax slate for grinding anywhere - but
would imagine a mortar would work fine.

Appreciate any feedback and thanks ahead,
Cynthia

2

Hello Cynthia

I have been using borax for twenty-five years now with no ill affects
I use an old part of a roof slate, a few drops of water rub the cone
on top and we have flux,but lift the cone of the flux or it will
disappear up the cone. when you finish,let it dry out, and some times
when you use it ,you only have to put a few drops of water on and away
you go.it is so simple you will cry

good luck an a’ the best
bob graham in rainy Edinburgh Scotland

3

Hello Cynthia,

A borax cone is just pure borax. It is only melted together into a
cone. In the old days there was a problem to get grinded borax and
keep it dry. Nowadays there are anti binding chemicals. But what you do
with a borax cone is simple. Take a dish with a rough surface. Put a
teaspoon of water in it, and grind with the cone until you get a
smooth paste. This is your flux. If its to sticky ad more water. Add
this with a brush on your subject. Do not leave the cone in the dish
otherwise it will stick itself to the dish after some time. When you
want to work after a few days. Just do the grinding trick again. An
other trick is, is to heat up your subject and take a tweezer with a
paillon if solder. Dip this into the borax solution and stick it on
the hot subject. This because borax solution will foam a bit when you
heat your subject up and the paillons of solder will jump of,. And
remember borax is a perfect flux but chemical what the call harmful.
you should not eat it. But further on it is safe. If you whant a borax
dish it is available by every jewerlry supply in the Netherlands. Give
me youre adres and i can send one. ther are very sheep or I can send
you my old one. I solder for the moment only for gold with Fluoron,
And for silver Fluoron and Degussa H.

Martin N.

4

piece of an old slate shingle wuld do just fine , or even a small
chip of slate flooring would do check your garden shop Leon K

5

Hi Cynthia, Although I haven’t used borax cones lately, (I use mostly
Auflux these days) I did use them for over twenty years and had no
problems. I began with grinding the cone on a slate (from a roof), but
later on used a ceramic dish with a surface similar to that of a new
crucible. That worked well and I didn’t get slate residue in my flux.

It rehydrates very well, and as far as I know there has been no
toxicity or noticeable after effects (I’m going bald, but so did my
dad). The cones last for years. Actually, you’ve made me wonder why I
stopped using them.

Kind regards from
Rex in Oz

6

Hi Cynthia,

This same subject came up recently in my shop as I am training my
daughter on the bench. She watched me using a borax cone, then
watched one of my bench people using commercial flux, tried both
methods, and decided she prefered the cones as she can “see” the area
to be soldered better. She also found cones available, but could not
find a slate anywhere. I finally located an old one stuffed in a box
of old tools, but seems strange that the cones are available without
offering anything to use them on. I leave the cone on the edge of the
slate, add some water to the center of the plate, and rub until a
light, “milkey” mixture is prepared. Cones seem to last forever, but
I would buy two now in case they dissappear from the future catalogs.
They should last you twenty years or more. Maybe someone on this
list can help you with a slate they are not using anymore. Good luck,
JMF

7

Hello, Martin

I agree. Borax cones are very easy to work with on a slate dish. A
friend gave me both several years ago. They last forever.

By the way, do you have any recommendations where I might purchase
sterling silver clasps. I am interested in both box and unusual ones.
Are there any suppliers that might send me their catalog?

Thanks.
Razine

8

Can you use 20 Mule team borax,the washing powder as flux. Iknow its
used in in welding steel by blacksmiths.

9

Cynthia, If the slate used for the Borax Cone is just slate used for
roofing and landscaping then look at a nursery where they sell
quantities of limestone, slate, river rock etc.
Annette

10

Hello folks,

I have wanted to ask this question before but timing now seems right.
Last year when I was in Tokyo at Tokyo Hands, a great store, I found
a low dish made of borax. I thought it was to be used for soldering
due to it maybe setting the right atmosphere around the work. I used
it once to solder something but it didn’t seem to have any effect
either good nor bad. So I put it in the drawer. But as it cost
about $30. I have always been bothered by the waste. Now I am
thinking it is to be used with the borax cone, which I have. In
Turkey we used a rough marble dish the same shape and size. Anybody
out there have one or used one? Am I right with this guess?? Thanks
for your help.

Sharron in humid and still very wet Saigon.

11 
   Does anyone have experience - or prefer using the borax cone for
flux?

Cynthia, the borax cone works just fine, and is highly regarded by
its devotees. In use, the dish (see below) is moistened with a few
drops of water, and the base of the cone is rubbed around in small
circles against the inside of the dish, until a creamy slurry is
formed. The cone is then “parked” inside the dish at one side, and a
small brush is used to transfer the flux slurry to the job.

   How does it hold up during soldering for different purposes and
with different metals?

Same as plain old borax, which is what it is. Depends what sort of
jobs you do, and what your style is (meaning, really, how quickly you
get the heat in and the job done). If you go in for prolonged spells
of heating then maybe (just maybe) you do need the commercial fluxes
which include fluorides. Maybe some of the special alloys need
fluorides, I don’t know. But for ordinary silver and gold straight
borax is just fine thank you. Lets face it, it has a longer history
of use in jewellery making than the fluoride containing materials.

   Once ground/dissolved for use, does it store well and rehydrate
easily in small >quantities for daily use?

You don’t really use it like that. As I described above, just rub a
little up in a few drops of water as you need it. Start with a clean
dish each day, it does seem to make a difference, though I cannot
think why it should. Maybe psychological.

   Also, I would imagine that a certain amount of caution should be
taken when handling the >borax cone during grinding

Not really. You are wet grinding, so no dust. Usual sensible
precautions like don’t lick your fingers… As to the fumes,
well, possibly not as bad as the fluoride flux, but best to avoid
breathing all fumes, of course. I’m just a hobby worker, so I don’t
produce much fume anyway (except when I’m annoyed… then I really
fume!). Commercial workers need the usual precautions regarding
ventilation. Borax itself isn’t really hazardous, in the quantities
we use. It’s been used in laundry work for ages.

   Haven't found the borax slate for grinding anywhere - but would
imagine a mortar would >work fine.

Ah, well, now you realise that you don’t pound the cone into powder
first, so a mortar isn’t really what you want, unless it is well
roughened inside. I suppose you could try a circle of coarse wet and
dry paper in a dish, at least for first trials, maybe.

You could do what I do, of course, which is to just buy a small box
of borax powder (from the chemist/pharmacy). Just ask for borax. I
put just a few drops of tap water in an egg cup, add the powder with a
spoon spatula, and then grind it a bit with the back of the spoon end
to mix. A few years ago at a summer school I had the chance to use
the cone method, and it certainly gave a smoother slurry than I get
from the powder, which may be important for some jobs, but I haven’t
found the need to change, even on tiny tiny soldering jobs. Good
luck, and have fun.

Kevin  (NW England,  UK)
12

I have been using Borax Cones along with other fluxes { Allflux &
Tenacity No.4} for 24 years as a full time Jeweller. I find borax to
be better than any other flux I have used for high melting point
solders. The other fluxes tend to burn away at the higher
temperatures. I use a small dish about 15 cm round to grind the borax.
I dip the end of the borax cone into water & then heat the end of the
cone directly with my bench gas jet until the end of the cone starts
to bubble. This causes the borax on the end of the cone to break up. I
then rub the end of the cone with a small amount of water in the
small dish. This method quickly forms a thickish paste & reworks any
flux left over from last time. I use borax when retipping claws as it
is less likely to etch the surface of stones.

I also use Boracic Acid powder to prevent polished jewellery from
tarnishing when soldering. Putting the flux on the job first & then
the Boracic Acid powder works well. Doing it the other way around I
find I sometime get dry or pitted solder joints. Don’t have a good
reason for this it just is!

Borax stores well when used this way as only a small amount is
prepared each time. I wash the dish in hot water every few weeks as it
picks up dust from the workshop.

It seems that the borax cone is a purer solution to be working with
for a flux - since it does not contain fluorides.  I have primarily
used Handy flux (in a well ventilated situation) over the years, but
it may be wise to change.  I'm sure that fluorides were added for a
practical purpose - but never questioned the difference - since I
always liked working with the Handy flux.

I find the other fluxes more convenient to use for general soldering
as they flow at lower temperatures which saves me time.

Also, I would imagine that a certain amount of caution should be
taken when handling the borax cone during grinding (from previous
threads on borax toxicity) - but am not sure of the risks vs the
benefits - and how careful one would need to be in handling the cone?
Sometimes the old ways have greater benefit - even if the speed of
convenience of prepared formulas have become popularized.   It would
seem that there is less risk of toxicity by breathing the soldering
fumes from the pure borax flux.

A couple of years ago I made a list of the chemicals that I’m exposed
to in the Jewellery trade & it turned into a long list. It was a bit
of an eye opener as it contained many that could cause permanently
damage or death. This caused me to have a rethink on handling
chemicals. I have had my blood tested for Cadmium & Cyanide twice in
the last ten years to see if the Cadmium in gold solders or Cyanide
from plating solutions was building up in my system. The results
showed my levels to be the same as the general population.

There were some old Jewellers where I did my apprenticeship who had
used these chemicals all there lives & didn’t seem any worse for it.
They may have been lucky or the damage wasn’t obvious from the
outside.

Taking sensible precautions with chemicals & keeping their number to
the smallest possible is always a good practice.

I am a new subscriber to this list & have missed the previous
articles on borax toxicity. Could you please give me a guide to where
I may find them? Thanks.

Hope this helps.

Cheers

Dean Watson

13

The dish you bought could not have been made from borax. As soon as
you applied a flame to it the material would have bubbled up, melted
and your piece would have disappeared into the depth. What you have, I
suspect, is the white ceramic dish that we use in the UK to grind the
borax cone on with water.

14

I’d recommend getting borax from a chemical supply house or from a
jewelry supplier, since the 20 mule team stuff has additives in it to
keep it from clumping, and even some perfume type chemicals. I do a
lot of blacksmithing, and I’ll use it if I don’t have anything else
better, but it’s not my first choice. When I worked for the old
trade guys back when, we used to get a powdered flux called #2 flux,
and you can still come across a similar product. Just put it in an
old salt shaker and dust a little in a small dish. Add water from a
small bottle with an eye dropper, and you can mix up a paste of the
consistency you want. I use the battern’s flux now, mostly, but I’ve
thought of going back to the old ways. As for a slate dish, I’ve
been through every catalog I have, and I swore I saw one once, but
I’ll be hanged if I can find it now. Slate is not that hard to work
with. You can cut it with cheap hacksaw blades (you’ll dull them
down pretty quick). You can clean up the edges with an old rasp.
Then grind out a depression with a spherical or disk shaped stone on
an arbor, using an electric drill. Finish the dish with coarse
sandpaper.

David L. Huffman

15 
Does anyone have experience - or prefer using the borax cone for
flux?  How does it hold up during soldering for different purposes and
with different metals?  Once ground/dissolved for use, does it store
well and rehydrate easily in small quantities for daily use?

G’day; I used a borax cone when I first began jewellery, and prior
to doing jewellery I used plain borax powder when silver soldering or
brazing brass, copper, or steel, all of course with excellent results.
Then someone gave me a pot of Easi-Flo flux and I never returned to
borax as I found the Easi-Flo did seem to clean up the oxides and
allow the solder to flow better. The borax worked well for all the
usual metals. To answer the third question above. I used the cone in
the time honoured method by putting a few drops of water on a bit of
slate then grinding the base of the cone on the slate, using the
slurry of borax to do the soldering, placing it with a little painting
brush. When I completed a task, I simply left the cone on the slate,
ready for next time. If it is difficult to get slate, used a piece of
ground glass. A glass merchant might give you a 4" square bit if you
smile nicely. If you want to grind your own glass, get some coarse
valve grinding paste from a garage/motoring supplier, put a little on
a bit of glass and rub a second piece against it in a circular motion.
Takes about two minutes to get sufficient ‘bite’ to use with a borax
cone. Grinding with a mortar isn’t at all necessary.

Borax is fairly innocuous, despite the fact that insects hate it;
just don’t eat it, wash hands before dealing with food, and avoid
sucking your thumb when things don’t go well without first washing it
. Cheers – John Burgess; @John_Burgess2 of Mapua
Nelson NZ

16

hello Razine,

What do you mean by clasps, is it for a neckty or something, or do
mean locking devises for chains and neclases? I have two suppliers
who have a lot of varyities in them, Send me you address and I can ask
them to send a catalog.

Martin

17

Appreciate the replies from around the world - Orchid is amazing.
I’m convinced . . . time to give the cone a try. As I suspected - the
borax cone is still being used more commonly in Europe and other parts
of the world.

Martin, I think I’d rather stop by and pick up your used dish - I
think the postage is too high to Hawaii - but I would love to visit
the Netherlands! However, I will try to find a slab of slate first!
A visit to Edinburgh or the UK would be wonderful too. And of course
Rex in Australia. (In Hawaii they call it “island fever” - when we get
the travel bug!)

There is something wonderful about grinding the flux - I can tell.
Much nicer than opening a jar. Reminiscent of grinding sumi-e ink
before Chinese brush painting. And yes, it would probably be a good
idea to buy two before they are out of stock. . . if my math holds,
that means they’ll last probably longer than I will! :slight_smile:

Thank you all for the detailed descriptions of how to use the cone
and store it etc.

Cynthia

18

When I read Cynthia’s post I realized that I have a standard way of
starting a days work. I clean the bench top down, put some Mozart on
the CD, light a cigarette (I know, don’t go on about it) and then,
slowly and with great deliberation, I grind my flux and plan the work.

Zen or what?

Tony Konrath
Gold and Stone
www.goldandstone.com

19

Okay folks – I have been reading this thread off and on for awhile
and I’m wondering (this is probably a stupid question, but one of
those in the ‘I just have to ask it category’) …this borax cone
that everyone is talking about – is this the same thing as the white
boric acid powder that I have mixed with denatured alcohol and dip all
my work into before I bring the torch to it??? If not, what is the
difference between the two materials?? If so – why would I mix with
denatured alcohol and not water??

Thanks for the info –
Laura
@LWiesler

20

No, Laura, borax [Na2B4)7.10H2O] and boric acid [H3BO3] are two
different “animals”. Borax is what you use for flux when soldering
silver. The reason you use the alcohol with the Boric Acid is so that
it will burn. (Obviously, a water solution will not do that! :wink: )

Margaret