I have a lazy disposition and besides I am not 20 anymore, so I do
not like all that rolling. I have a couple of ingots, just the usual
kind. The opening is a bit smaller than 4 mm. Since I do not like to
roll, I had the idea of filing the opening of the ingot smaller -
now it is still 2 mm wide. I have been pouring hundreds of ingots, so
I know what to do. But today everything went wrong.
The metal - Sterling - just doesn’t flow into the ingot and now I
begin to think that the capillary force is stronger than the
gravitational pull. If that is true, I messed up my ingot and have
to buy a new one. What do you think?
If that is true, I messed up my ingot and have to buy a new one.
What do you think?
To cast the thinner ingots, you need to heat the mold hotter. Also,
lubrication of the mold surface is more important. Oil the thing,
then heat till the oil is smoking, and the mold considerably too hot
to touch. Another good surface lube, less smelly, is if you’ve got an
acetylene torch (any type). Use just a plain acetylene flame (block
the air inlets on an air/acetylene type torch), so you have a bright
yellow sooty flame. Use that to coat the inside surfaces of the mold
with a good layer of carbon. Either this, or the oil, (don’t use too
much. Just enough to make the surface slightly oily before heating
the mold) will help cut that surface tension. Then a hotter mold, and
if needed, slightly hotter metal (not too much. a hotter mold first,
then if that isn’t enough, increase the pouring temp slightly.) Also,
be sure the ingot mold is not such a perfect tight air tight fit
between the sides. You want a little trace of a misfit, a tiny bit of
gap, usually just from coarser machined surfaces, so that air can
fully escape as the metal enters. That trace of flashing one gets on
the edges or ends of an ingot because of those slight gaps may be
annoying, but they help get a more complete fill, especially on
smaller/thinner sizes of sheet and wire ingots.
By the way it should be mentioned that though the extra rolling of a
thicker ingot is work, the result is usually better quality metal.
Rolling and annealing and rolling give you more uniform and stronger
sheet. If your poured ingot is only slightly more than you’ll end up
with, you loose some of that benefit.
but if you dont roll or forge down the ingot, its going to be pritty
useless even if you could get it to pour. the grain stucture will be
very poor (large).
i dont think capillary action will be working against you. its
probably that the mold is to cool and the metal is freezing up. i’ve
always found silver ingots really tricky at the best of times.
Are you speaking about an “ingot mold”? The ingot would be what you
make with the mold, yes?
If your ingot mold is not producing a good ingot, I would look at a
couple of issues. Is your torch hot enough to make the silver liquid
enough to pour well? Have you oiled your ingot mold too much, and the
air cannot escape from the mold while pouring?
Perhaps the hole you are pouring into is just too small to pour a
decent ingot?
In my opinion, keep your ingot dry for your own safety. Any wet
ingot is subjet for uncontrolled evapuration of the hot metal causing
burns and other injury’s. A hot liquid metal on a wet surace is
asking for trouble. If someone can’t show you visualy what it is
means to oil an ingot it is a free visualtisation en interpretation
of how wet or dry an ingot has to be.
The idea of using the soot coming from acetylene is however a safe
way. However, keep your flame as close as possible to your ingot to
give the soot the possibility of covering the ingot directly. All
other soot will be realesed in the air and that soot can be inhaled!
So, be aware of twhat you are doing and think of what you’re doing.If
you don’t have acetylene gas then you could use a normal candle light
which gives you plenty of soot to cover your ingot. Tilting the ingot
slightly to one side can give you better results aswell.
The soot on the inside of your ingot has another advantage. In
matter of fact, it is carbon and this carbon will absorbe oxygen
which will be released when the silver solidifies. It’s just a small
thin layer but it’s better then nothing.
The big message is, don’t copy things because someone tell you so.
It is treu and oil can be used but think again, spill a drip of water
on a hot plate and watch what happends, same thing and this water is
free to act in a free space. Oil is closed inside your ingot and will
find it’s way out! The silver is hot and will burn through your skin,
no thought!!