I can't melt 1oz ofSterling

[Byzantine]

Hello, I joined the forum because I cannot bring 1 ounce of sterling
silver scrap to a flow point so that I can pour a 1 ounce ingot of
silver.

Items used.
1. 32 g of acid tested sterling. The silver was cut into small pieces.
2. A silica crucible bought on eBay from FindingKing jewelry supply.
3. BurnzOmatic propane torch model TS 4000.
4. Prograde propane fuel.
5. Two syntax butane micro torches model number, SX 2050.
6. Titanium stirring rod.

The crucible has a round bottom. So I set it on a 1 1/4 pound cast-iron
weight with a hole in the center. The crucible fit perfectly on it.
First I tried a flux of straight Borax and water. I added too much water
so the water boiled and turned the Borax to a consistency of cottage
cheese, when it finally melted it looks like black lumps. Next I tried a
50-50 mix of Borax and boric acid. This time I use less water, and I
made a mixture to a consistency of dough. I still had some water
boiling, but eventually, the flux melted and turned smooth black.
I put the 1 ounce of sterling scrap. On top of the melted glassy flux
and began heating, first with one micro torch. Then with two micro
torches this will not bring it to the proper melting temperature. So I
changed over to the propane torch.

The highest temperature I can reach on the silver is to a bright
maraschino cherry red and and silver will not melt, although it will
fuse the parts together. The corners of these pieces have rounded off
and the lump is fuse together. The crucible has reached a bright orange
color. I have seen bright green flames coming off the silver as the
copper burns off. Most of the green flames have now stopped.
I thought maybe the cast-iron weight was absorbing heat from the
crucible. So I held it in the air with tongs but no good results. At
this time, I have used nearly a full can of propane and over 1/2 hour of
heating time. I realize a second can is not going to melt the silver.

Can anyone please help me to understand why I cannot melt the sterling
silver. I realize that there is a problem, but I cannot identify it.

Regards, Byzantine




--
Byzantine

[Ted Frater]

Simple really.
Aint hot enough.
your losing more heat than your putting in.
Dump the cast iron.
Get some fire bricks
lightweight type.
use one as the base with adepression in it.
make a wall with the others some 2in wider and 3in higher than the
crucible. use fencing wire to hold all together.
make a tangentical hole in the side and bottom of the wall to take the
torch. you will need one with at least 1in in dia burner.
Use a minimum 7lb upward propane tank and regulator.
make a 1in thick slab to put on top of your wall with an 1in hole in it
to let the flue gases out.
Light up and stand clear.
Should melt in 15 mins once bright cherry red inside.
usual safety precautions etc. At your own risk.
I have this setup on a much larger scale using a 2in dia torch and 48kg
propane tank and reg.I use easyflo flux on top of silver.
Pour through a reducing flame into your mould.
If castiron use olive oil in mould.
Will melt 8 oz siver no problem.
Insulation is the key, to keep the heat from leaking away.
Think anchient metalworkers, charcoal clay crucible and hand bellows.

[Peter W. Rowe]

On Sun, 19 Feb 2012 10:44:50 -0800, in rec.crafts.jewelry Ted Frater
<ted.f...@virgin.net> wrote:
>>
>>Simple really.
>>Aint hot enough.

>>Get some fire bricks

>>make a tangentical hole in the side and bottom of the wall to take the
>>torch. you will need one with at least 1in in dia burner.
>>Use a minimum 7lb upward propane tank and regulator.

Um, Ted?

The poster has a problem melting silver because he's using too small of a torch.
Otherwise, mostly doing the right thing (Although the iron is a heat conductor,
it won't be chilling the metal much when melting in a clay crucible, as he's
doing. Graphite would be a different story, but he's using a clay crucible.

But anyway. He simply needs a bigger torch. Instead, you've not only got him
needing to get a whole new bigger torch (a 1 inch burner is a MUCH bigger
torch), and a regulator and tank and all, but then you've got him building a
whole little melting furnace.

Sure, it would work just fine as you describe. But he's trying to melt one
ounce of sterling. Not 8 ounces...

While your melting furnace design is a classic and fine one, for what he needs,
it's overkill, I think...

All he needs is a bigger torch... What he's got is almost big enough, just not
quite there. It's also possible that using a smaller crucible would do the
trick too. One of the smaller melting dishes perhaps. Though a bigger torch is
more likely the requirement.

And Byzantine, did you get the reply I sent you in email?

Peter Rowe
moderator
rec.crafts.jewelry

[Ted Frater]

From all the years ive been on rec crafts jewellery and recently
ganoksin, it seems lots of folk think thay can achieve professional
results with amateur equipment.Furthermore dont have any engineering
background or experience.
they just dont seem to think their technolgy through before they start
then complain when they dont get results.
As you know one needs the right tools for most jobs.
the fire bricks i mentioned are so easy to use. one cuts them with a
wood saw.
they're a white spongy texture. .I guess most folk that want to make
jewellry dont use 1 in dia torches.

[Peter W. Rowe]

On Mon, 20 Feb 2012 09:47:53 -0800, in rec.crafts.jewelry Ted Frater
<ted.f...@virgin.net> wrote:

>> From all the years ive been on rec crafts jewellery and recently
>>ganoksin, it seems lots of folk think thay can achieve professional
>>results with amateur equipment.Furthermore dont have any engineering
>>background or experience.
>> they just dont seem to think their technolgy through before they start
>>then complain when they dont get results.

Agreed. However, it may be worth pointing out a couple advantageous aspects to
this. Some people learn a craft the "right" way, via instruction from good
books or better, good instructors. They get taught the right way, and get good
results from the start.

Other people, perhaps without the availability of good instruction, and not
knowing where to find the information, attempt to teach themselves. While this
approach is slower, and fraught with the frustrations of failures, there's
something to be said for this. For one, it requires some motivation to keep
experimenting and working out the details. That's worth mentioning all on it's
own. But more, people who work out the details on their own not only learn the
right way, or at least, a way that works for them, eventually, but they also
gain considerable experience in the wrong ways, and why these are wrong or don't
work. The result is a body of knowledge and experience that, though naive in
ways, may also be a bit more in depth, with a greater degree, at least in the
early stages, of an understanding of the whole thing. Rather than learning to
do a thing just by being shown "here's how you do it", they end up understanding
WHY they do it that way instead of another. That's valuable experience. Best,
of course, is good enough instruction and information resource that people would
not only learn the right way, but along side, also learn the why, and what not
to do. But that comes with a longer learning curve.

>>As you know one needs the right tools for most jobs.
>>the fire bricks i mentioned are so easy to use. one cuts them with a
>>wood saw.
>>they're a white spongy texture. .I guess most folk that want to make
>>jewellry dont use 1 in dia torches.

Again, true on all counts. Fire bricks are useful things to have around in
general, and are really inexpensive, though not all hardware stores may carry
them, so someone may have to hunt around a bit for a source. Anyone working
with hot metals will have uses for these, if only to protect the surfaces they
work on. Still, as I noted, building an actual melting furnace, as you
suggested, while a valuable learning experience, as well as an effective means
of melting larger amounts of metal, is perhaps not needed for melting smaller
amounts like an ounce or so of sterling.

It may be noted too, that if someone wishes, and does a bit of background
research, making a burner for such a melting furnace can be done easily enough
with little more than some plumbing pipes and fixtures. Add a gas valve for the
propane feed, and a simple blower, even just a hair drier, for an air source,
and you can build a furnace capable of melting pounds, not ounces, of
non-ferrous metals. In fact, such a design can be ramped up a bit without too
much extra cost, to build a version capable of even melting cast iron...

It's also possible to build a furnace like this that does not need a gas source,
but instead, burns coke or charcoal, needing only the air blower. That takes a
bit more finesse to build well, but again, can be done on a very limited budget.
It should be noted that most of these furnaces are safer to operate (and some,
like the charcoal fired one, must be operated) outside, or with equivalent
ventillation. The charcoal fired one may be more suited to lower melting metals
like brass or aluminum, but with care, could melt silver too.

Here's one book that details construction of such a charcoal fired furnace.
http://www.lindsaybks.com/dgjp/djgbk/char/index.html

That website, by the way, also is a source for a wide range of interesting
things, mostly reprints of old time books, and newer "how to" metalworking books
and pamphlets geared to the hobbyist and tinkerer...

Anyway. 'nuff said.

Peter

[Ted Frater]

Your extended comments are always a joy to read.
Hope some others might just get to read them too.
Interestingly my first experience of melting was years before I took
up metalworking.
It was on the backwaters of poole harbour. On a bank. A tin shed had a
circular brick furnace set in the bank some 4 ft deep and 18in wide.
In that the 2 old men put a graphite crucible that took 25lbsof scrap
bronze. It was surrounded by coke then blown with a vacumn cleaner.
It melted the bronze in about half anhour whereupon they poured it
into sand moulds they had made in the shed.
worked very well.
Apart from asmall furnace I mae along the lines I outlined ive also here
one some 2ft 6in high some 18 in od steel cased with fire brick lining
and lid. takes a 9 by 5in crucible propane fires.d.
Used it for all sorts of melting projects.
inc scrap silver. To turn mainly into wire .
But hey, ive been at it some 45 yrs plenty of time to do allsorts!!
Ted.

[Ecnerwal]

For a crucible suited to a single ounce of silver, a single soft brick,
suitably bored out, might well be a perfectly adequate micro-furnace,
and is quite simple. As is Ted's larger idea, though I'm not sure such a
large torch is needed unless the crucible is far oversized to the small
amount of metal - adequate insulation makes any torch more effective.

It's certainly far more efficient, and perhaps even cheaper (for the
single ounce, even) than just throwing more torch at it. ie, the fuel
savings alone (or certainly combined with a lesser need to buy a much
larger torch) possibly exceed the cost of the brick.

That said, I have seen an ounce (or so) of pure (not sterling) silver
melted without even a rudimentary one-brick furnace - easy-peasy for an
oxy-acetylene welding torch of suitable size. With a reducing flame you
hardly even need flux if you pay attention to where the flame is. But
that's a heck of a lot more investment than a soft brick or 4 and a few
minutes of filing/sawing/drilling.

A soft brick, in combination with the TS4000 torch "Byzantine" has
already got will probably do the job on plain old propane (heaven knows
what "prograde" propane is, other than a way to part fools from money)
and could even (for a few dollars/euros/pounds more) be swapped up to
MAPP if more firepower is desired without going hog-wild on new torches.

However, (being perhaps somewhat uncharitable in my assessment, but that
was based on what I read) I questioned the worth of trying to explain
that to someone who could not see for themselves that the torch and/or
insulation were inadequate (and was adding water to borax, which,
unwatered, melts just fine in my experience at the temperatures where
it's needed as a flux.) These are not deep mysteries or trade secrets.

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