Does anyone have experience - or prefer using the borax cone for
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)