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Buying ingot molds


#1

Hello all;

I am new to metalsmithing an am interested in purchasing an ingot
mold. We’ve all got scrap and the penny pinching nature I’ve
developed about my scrap silver is to reuse it. I’ve been doing salt
casting, but would like to make sheet metal or wire.

The mold I’ve found in one of the online retailers can be used for
either wire or flat to make sheet metal. But as I’ve discovered with
most other items purchased in this learning process, nothing comes
with instructions! Sheesh! Ladders come with instructions these
days!

Ok, now that I’ve vented, does anyone know if an ingot mold be used
by pouring molten metal into it as done with salt casting? Does it
need to be coated with flux or some other materal to be able to
remove the silver ingot? Does it need to be used with a
spout/funnel?

I am a member of FSGNE; I’ve asked one of the members, but she
doesn’t know if the group has a “guild” owned one or not. I am also
assuming that you wouldn’t want to mix metals in them, right?

Any help you can provide to this novice will be welcome. I learn so
much from you all, maybe in about 20 years I’ll be able to provide
some knowledge to someone else!

Thanks all,
jj


#2
The mold I've found in one of the online retailers can be used for
either wire or flat to make sheet metal. 

i assume you’re talking about one of the reversable sliding molds,
with two plates. Assembled with the flat sides facing in, one can
pour varying widths of flat ingots for sheet metal, while when
assembled with the vertical holes lined up, you pour round rods to
roll and draw into wire. This type of ingot most is usually the most
versatile, and is usually the right choice, especially for a beginner
at this.

But as I've discovered with most other items purchased in this
learning process, nothing comes with instructions! Sheesh! Ladders
come with instructions these days! 

Ladders come with instructions because it’s assumed everyone buying
one is an idiot who will fall off and then sue the manufacturer.
Ingot molds by contrast, are likely considered professional tools and
it’s assumed that those buying them would have some idea how to use
them. Besides, if you mess up, it’s not likely that the mold itself
will do lawsuit worthy damage…

Ok, now that I've vented, does anyone know if an ingot mold be
used by pouring molten metal into it as done with salt casting? 

No idea how you’re doing salt casting, but ingot molds are used by
melting the metal in a pouring crucible and pouring it into the mold.
So that’s likely pretty much what you’re doing with the salt…

Does it need to be coated with flux or some other materal to be
able to remove the silver ingot? 

Usually, yes. There are a few options. Easiest is a light coating of
oil. Ordinary automobile oil, light machine oil, or the like. Just
enough to the surface is lightly oiled, not dripping. The other
common choice is carbon, or soot. You’d do that with the flame from a
torch without air or oxygen, so it’s a bright yellow flame. Hold the
ingot mold above it until it’s uniformaly coated with black soot.
Over time, you’ll likely use both methods from time to time, so
eventually the mold will be covered with a mix of soot and burned
oil…

You use flux to melt the metal, but you do not flux the mold. Doing
that might allow the molten metal to actually “wet” the iron mold,
which would not be good. In essence, that would be soldering your
ingot to the mold. Not what you want at all.

Does it need to be used with a spout/funnel? 

No, the molds have flared ends to the round holes and the flat sides
too. You’re supposed to have good enough hand eye coordination to be
able to pour the molten metal into those holes directly. With the
glare of melting metal, this can indeed sometimes be a bit of a
challenge, even for those of us with experience. But if you miss, and
not all the metal goes where you want, just put it back in the
crucible, remelt, and try again. You’ll have to do this from time to
time when the ingot doesn’t come out good enough. No big deal.

By the way, there’s a bit more to this than merely coating the mold.
If pouring round rods, be sure the mold is lined up accurately, so
the rods come out without excessive fins or displacement at the mold
line. Also, be sure, with either wire ingots or sheet, that the
movable side of the mold is firmly all the way down onto the base.
Sometimes, when tightening the clamp, you can slightly lift up the
bottom of that plate, and then the metal can run out the bottom.

When your mold is set up right, set it on a suitable fire proof
surface large enough so if you spill, the metal is not lost or on the
floor or something. Then, put a nail or a bit of something under one
end of the base, so the mold is very slightly tipped. This helps the
metal flow in without trapping air, especially when pouring rods
instead of flat ingots.

Now preheat the mold. This is critical. If you pour molten metal
into a cold mold, there will likely be a bit of condensation (just
from the combustion products of the torch flame if not already there)
in the mold, and when metal hits that moisture, it can literally
explode back out of the mold. Nasty and dangerous. So preheat the
mold. This is where using oil to coat the mold is handy. You can heat
the mold until the oil is smoking (even after you pull the flame
away). That’s a nice indicator of when the mold is hot enough. It
will be a lot hotter than you’d want to touch, so be sure it’s
properly located before you preheat. And you’ll want a pair of pliers
or two to handle the mold and clamp screw after pouring, since it
will still be too hot to touch.

With the mold hot and slightly smoking, melt your metal, with a bit
of flux and a slightly reducing flame, and when it’s nicely liquid,
pour it into the mold. Try for an even uninterrupted stream of metal.
Not a halting uncertain pour nor a sudden dump-it-all-in one either.
Especially when pouring silver, as you pour, keep the torch flame on
the metal and try to have the flame extend over the top of the mold,
so the pouring metal stays within the reducing atmosphere of your
flame. This can be tricky, but try, at any rate.

You may find, by the way, that with silver, getting good sheet metal
is a lot harder than getting good wire. The reason is that silver
tends to absorb oxygen and gasses when molten, and gets rid of it as
it cools. That leads to small bubbles in the solid metal. When you
roll an ingot with these out into sheet, they spread out into blister
shapes, and when you anneal, the puff up,messing up your sheet metal
(it was already messed up with the blister cavities, but you don’t
know it till it puffs up…) With wire, however, any such little
bubbles get rolled down to a long thin threadlike shape pretty much
down the center of the wire. Sometimes it will form a defect in the
surface, but usually that’s a small portion of the wire, more easily
avoided than a defect in the middle of a piece of sheet metal.
Anyway, if it’s a long threadlike inclusion in the wire, then the
smaller you draw the wire, the smaller that defect becomes too,
instead of spreading to a wider and wider blister as it does in sheet
metal. With wire, it just gets longer, along with the wire, but
doesn’t otherwise get in the way of normal use of the wire. As I
said, you may now and then find defects in wire you make, but usually
most of it will be usable.

For me, I make my own sheet and wire when working with platinum or
gold. But with silver, I buy commercially made sheet metal and use my
scraps only for wire, or for casting.

I am a member of FSGNE; I've asked one of the members, but she
doesn't know if the group has a "guild" owned one or not. I am
also assuming that you wouldn't want to mix metals in them, right? 

If you use an ingot mold to melt metal in directly, the mold will
become hot enough the metal will wet and adhere to the mold. That
will destroy both your ingot mold and the metal (which then will have
some iron in it as a contaminant). You use the molds hot, but not
THAT hot. Usually they’ll be somewhere around 300 - 400 degrees F or
so at the most, and covered with a carbonized layer of oil and/or
soot, so the metal doesn’t stick. If you melted the metal in them
directly, you’d defeat that protection.

By the way, if you find this too frustrating, remember that your
scrap is almost as valuable as new metal. You can send the scraps to
any decent refiner in trade for new metal. They take a percentage of
course, but if you weight the value of your time, you may find it’s
more efficient to buy your metal already as sheet and wire, sending
scrap in trade. This is more likely to be the case with beginners,
who may end up spending an inordinate amount of time trying to get
good ingots. I’m not trying to dissuade you, of course, just
remember you have the option.

Hope that helps
Peter Rowe


#3
does anyone know if an ingot mold be used by pouring molten metal
into it as done with salt casting? Does it need to be coated with
flux or some other materal to be able to remove the silver ingot?
Does it need to be used with a spout/funnel? 

To prepare a mold for casting - clean it with wire brush and smoke
it with regular candle. Soot is the best separator. Mold must be about
400 degrees before pouring. Mold also should be slightly inclined,
one or two degrees will be just fine. No funnel is necessary, nor it
is possible. One is going to have to learn to pour, so practice,
practice, practice. Good ingot is bright and blemish free. Enjoy.

Leonid Surpin
www.studioarete.com


#4

There are numerous kinds of steel ingot molds for sale.

There is the long trough-type with a handle, and the 2-piece upright
kind with a clamp for holding it together. My favorite is the
"combination ingot mold" which has grooves for making wire ingots,
and adjustable flat sides for making sheet ingots of any width. They
work great, and will last forever. When you get it, it will be covered
in grease. Wipe as much off as you possibly can before using it, as
you will want air to escape between the sides of the ingot mold as
you pour hot metal into it. This very slightly oily surface will help
prevent metal from sticking to it. Sooting the ingot mold with either
a candle or straight acetylene is also good to prevent sticking. Be
sure to heat the ingot mold before you pour hot metal into it, to
drive off any possible moisture, which could cause the metal to blow
back out of the mold upon pouring. If your sheet ingot comes out with
funky ( not straight) sides, you probably aren’t getting your metal
hot ( liquid) enough to pour, or not pouring fast enough.

Provided you clean off the metal bits between pours, which you’ll
need to do anyway to get the ingot mold to “seat” properly, you can
pour about any metal you can make liquid with a torch. The only
metals I can’t get hot enough with propane/oxygen to pour into my
ingot molds are palladium and platinum.

I use a WHIP (wire handled ingot pourer) and ceramic melting dishes
to pour my ingots. All the big suppliers carry WHIP’s in their
catalogs now, I think. I use a different dish for each kind of
metal. You won’t need a funnel of any kind, and the WHIP will get
that melting dish right where you need it to be for a good pour,
resting on the top of the ingot mold.

Keep that hot flame on the metal as you pour, and be sure to wear
safety glasses!!

Jay Whaley


#5

Peter,

As usual, an outstanding response, clear and concise. For those
having difficulty with the pour itself, Jay Whaley invented The
WHIP, Wire Handled Ingot Pourer. It is available from most Catalog
companies.

This simple, inexpensive device comes in two sizes and 4 size
crucibles fit within, two in each. It can be used by both left and
right handed folks.

It can be seen in a couple of Jay’s free video clips. I easily pour
into the smallest end of the ingot mold, and the last one was too
beautiful to roll out, could be simply shaped into a round cuff. Not
a fin visible.

Hugs,
Terrie


#6
sending scrap in trade. This is more likely to be the case with
beginners, who may end up spending an inordinate amount of time
trying to get good ingots. I'm not trying to dissuade you, of
course, just remember you have the option. 

I respectfully disagree. Learning how to melt teaches allot. They are
going to melt stuff any ways, better on an ingot which can be quickly
re-done than on a piece with hours invested.

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand


#7
I respectfully disagree. Learning how to melt teaches allot. They
are going to melt stuff any ways, better on an ingot which can be
quickly re-done than on a piece with hours invested. 

Jeff, I think you slightly misinterpreted what I wrote (or at least,
meant). I fully agree that learning things is important and useful,
and certainly doing this with melting ingots is far better than
learning it by accidentally melting the work (though this is a
valuable lesson too…) My point, however, was simply that in the
case of silver sheet metal, it can be frustrating for even pros to
get good consistent results all the time, and for that reason,
sometimes one might be well served by not feeling obligated to always
cast your own ingots rather than using the services of a refiner.
This does not mean the students should not try to do it, or learn
how. It just means they should also know they have the option
available when needed. If you’ve got a bunch of scrap silver, some of
which may even be a bit questionable with traces of solder, and what
you need is a high quality piece of sheet metal, then even knowing
how to pour a good looking ingot may not help without quite
sophisticated equipment, since hand poured ingots may look good, but
in silver, are prone to have small internal defects that cause major
problems once rolled out. Knowing this, should the student (or
seasoned pro, for that matter) spend a bunch of time trying to get
it to work, or would the time be better spent elsewhere. You’ll note
that in my original reply, I said that this problem is mostly in
making good sheet metal, but that making ingots for wire, generally
have much more success. Learning to melt and pour an ingot is just as
effective in pouring rod ingots for wire as it is pouring flat ingots
for sheet metal. Pouring ingot after ingot for sheet metal, rolling
it out, and finding yet again, that there are once again blisters
forming in the metal that make it unsuitable for use, doesn’t teach a
whole lot. Good physical activity though, if you need the exercise…

Peter Rowe


#8

I love the WHIP. Jay gave me one earlier this year and it is sweet.
Heats up quickly, stays cool at the handle and is nice and light. You
can change crucibles easily.

Andy


#9

if this is a once or twice situation, use hardwood. i have a
woodworking shop, and can make a wooden ‘ingot mold’ that will let
me pour a couple before the negative space gets too charred. they
work and look a lot like the horizontal channel molds already
mentioned.

even clay could be used, as that is another material used to cast
metal into negative space.


#10

I have put a post on my blog: ‘On Your Metal’, on Ganoksin Blogs.
‘Melting and Pouring System and Flexible Mold for Ingot Removal’.
This a system that can be easily made and is especially useful for
recycling small quantities of scrap, or alloying.

http://davidcruickshank.ganoksin.com/blogs/2010/10/22/

I have found the pours very easy and the construction of the hinged
mold gives perfect square ingots which are easily removed. After
cutting off the plug and filing off any flashing, the ingot is ready
for rolling. I hope this is useful.

David
jewellerydavidcruickshank.com.au


#11

Here is my method of making an ingot mould.
http://www.meevis.com/jewelry-making-class-making-a-ingot.htm

Very easy and cheap.
Cheers, Hans


#12

Peter,

Thank you for the wonderful “lesson” on pouring ingots. While I
still buy my sheet and wire, it’s going in my How-To file. One of
these days I’ll get around to giving it a try. If only for the fun of
it. :slight_smile:

Michele


#13

Further to my blog, ‘Melting and Pouring System and Hinged Mold for
Easy Ingot Removal’

I have included 2 photos to further illustrate the system.

David Cruickshank
jewellerydavidcruickshank.com.au


#14

Am very curious after have read the articles and seen a quick video
on pouring ingot molds…having no real experience with it…and also
taking into consideration the breadth of knowledge and creativity and
innovation that I see from the people here. My question is…why
aren’t the sheet ingots done by some sort of horizontal press rather
than the pouring vertically? I am sure it’s been tried but to me
(although I realize metal makes a “bead” when heated) it seems you

would be able to somehow control it better and ensure even pressure.
Would love to know why it’s done the way it’s done?

Thanks,
Helen


#15
My question is...why aren't the sheet ingots done by some sort of
horizontal press rather than the pouring vertically? I am sure
it's been tried but to me (although I realize metal makes a "bead"
when heated) it seems you would be able to somehow control it
better and ensure even pressure. Would love to know why it's done
the way it's done?

What you’re suggesting is just a lot more complicated. A vertical
mold is simply a slot shaped mold you pour metal into. Very simple to
do, very direct, and effective. You get out an ingot with uniform
structure and with even thickness, which is what you need for rolling
it down in a rolling mill. I’m not sure what you’d be doing with
pressure. A normal ingot mold doesn’t apply pressure in any way. Not
needed.

Sometimes, if one needs a bit of sheet metal but does not have an
ingot mold, you can melt a bit of metal on a smooth surface, such as
a new charcoal block, and press another one down on top of it, to
push the molten blob into a flat shape as it cools. This does work,
but is not as reliable as just pouring it into a mold, and you kind
of need a third hand to do it. Getting the thickness uniform is
tricky, even if you use some sort of guides to limit how far down
you can press the top surface. Doing the same with the sort of steel
mold an ingot mold is made of, would not work well, because you’d
have a hard time simply melting the metal against that heat sinking
surface. If you did melt the metal, then you’d have raised the steel
surface to a similar temperature, at which point the molten metal
would try to solder itself to the steel. Not at all what you’d
want…

Commercial large scale production often uses another method,
continuous casting, which amounts to a melting crucible which has a
hole or slot in the bottom. This is arranged so that molten metal
simply flows down into that slot, but the slot is designed with
enough depth, and so that at the outside edge it’s cooler, so that by
the time the metal has flowed through the hole to the outside, it’s
solidified enough to hold together. So this shape now drops down
from the crucible in a continuous bar, ready to feed to the rolling
mills. The method avoids problems such as shrinkage voids in the
middle of a cast ingot, which you can get with a normal poured ingot,
and the length of the ingot can keep right on going if you keep the
crucible topped up with metal. This type of equipment, though, is not
normal “studio” level equipment, but rather, the sort of thing you’d
find in a large refinery or metals supply/production company.

Peter


#16

This probably is not an answer to your question, but is an
interesting story.

Several years ago, while teaching a jewelry class at UCSD, I had an
engineer “consultant” in my class. He made a point that he was an
engineer, and he implied that he probably knew a lot more about many
things than I did. He had some antique Roman coins he wanted to
reproduce. I told him to do it properly, we would need a large
coining press with steel dies of that Roman coin. We didn’t have that
kind of equipment, but we did cast him a berilium copper die of the
face of his coin, and I explained that we would have to strike that
die onto a small button of 24K gold with a heavy hammer to make an
impression on it, and continue to anneal, strike, re-anneal, and
strike until we had finally worked the image deep enough into the
gold “coin”. The engineer insisted to me that the early Romans struck
their coin dies into LIQUID molten gold to make their coins, rather
than on solid metal, as I had suggested.

After much argument with him about what would happen when he smacked
his die into molten gold, he insisted he wanted to try out his
method. Wearing safety glasses, gloves, and fire-resistant apron, he
put down his torch, smacked the still molten metal with his die…and
the molten metal flew all over the room. Duh. He was able to recover
about half the gold he had originally, and he left the class. I never
saw him again.

Back to your query about how ingots are poured.

Liquid metal (silver, gold), when poured, tends to set up pretty
danged fast. It doesn’t tend to “settle into level”, as you might
expect, but into whatever thickness you are lucky enough to control
by your pour. Personally, I’ve never been able to get any kind of
consistent thickness of ingot by pouring into a horizontal (trough)
type of ingot mold. I spend more time with the rolling mill getting
that uneven thickness fixed. I have better luck with a vertical
2-part ingot mold. I can control the width of sheet I want to make,
relative to the amount of metal being poured into the ingot mold. I
always want to pour a vertical-shaped ingot, which makes the most
even, flat ended shape. If you pour a small amount of liquid metal
into a wide vertical slot, you get an uneven little lump at the
bottom of the ingot mold. The same amount of metal poured into a
narrow slot will create a pretty even tall shape with smooth sides
and square ends. A nice shape to begin rolling out with the mill.

If the ingot is too narrow, then I will roll it sideways until it is
wide enough, then roll it out lengthwise to make it longer and
thinner.

Hope that helps!
Jay Whaley


#17

Hi Guys,

A steel ingot mould is nice and I have a couple, but I don’t really
use them anymore.

I prefer to use delft clay, for a couple of reasons.

Steel is a good conductor of heat and cold, so if you want to use a
steel ingot mould you have to heat up the mould so that your melt
wont freeze on contact.

What I have found (and no doubt anyone that uses delft clay) is that
the ingots produced are clean, solid and lovely to roll straight from
the melt.

How I use it, I get a container, and fill with the clay. I then
either use a piece of sheet or stock gauge to give me my cavity. I
make a button, then pour the metal. If I want to make a sheet and a
piece of stock gauge at the same time, no problem, just make another
impression in the clay. You can make really thin sheet, thinner than
the steel adjustable ingot mould I bought.

It takes very little time to set up, and if you’ve screwed it for
some reason, the reset time is quick.

The plus side is, it’s quicker and pretty much idiot proof, the
ingots are fine and ready to roll.

The down side is the clay is quite dear (you could make your own
cheaper, but to achieve this properly you’d need a muller), and you
do lose a small amount as the clay burns in contact with the melt.

Regards Charles A.


#18

Thanks do much for satisfying my curiosity and helping me learn.
Really appreciate the effort and willingness that you both give to
the Ganoskin…I have learned so much and am sometimes the "whys"
are as important me as the “hows”.

Thanks Again,
Helen


#19

Square section ingots

If you look on my Ganoksin blog: ‘On your Metal’.
http://davidcruickshank.ganoksin.com/blogs/

I have two recent posts:

  1. Drawing and notes on joined crucible and mold. The mold will
    produce a square section ingot, ideal for rolling.

The mold is also hinged making ingot removal easy.

  1. Two images of the setup preparatory to melting.

David
jewellerydavidcruickshank.com.au


#20

I agree with Charles on this - Delft clay is really good. If you’re
doing meltups of an ounce or less, a 1 kilo bag of the clay will
last for a long time - we’ve got through no more than half a kilo
over two years. Obviously, if you’re making larger ingots, then
you’ll use more, but you only need to scrape of the top layer of
burnt clay.A foundryman gave me some advi= ce about doing larger jobs
with it - you can use low grade casting clay to pad out you
container, and just a small amount of delft to cover the surface. Not
tried it yet, but it sounds sensible.I get really nice "bread loaf"
open-cast ingots from it; they just need a few taps of the hammer on
top, and they are perfect for rolling or hammering. I’ve never once
had a problem with porosity, cavities or flux contamination, and I
must have done 200 small ingots since we got it. The only thing that
ever lets me down is if I pour badly, and as Charles says, clay is
more forgiving than a metal ingot mould.While we’re on this subject,
the university I’m doing somework at has a big bag of delft from the
70’s, which has dried out. Does anyone know a way to restore it to a
working state? It’s too crumbly ATM.

Jamie
http://primitive.ganoksin.com