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First Cast



 
 
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  #1  
Old April 19th 09, 06:26 AM posted to rec.crafts.jewelry
Muso
external usenet poster
 
Posts: 10
Default First Cast

Hello again, folks. Well, My first cast took two tries, so I will
describe the first try first. I filled a one-tablespoon stainless
steel measuring spoon about half way full with zinc nuggets, and then
I heated the spoon with a propane torch. The torch made a red spot on
the side of the spoon, though the zinc did not seem to be melting. In
retrospect, I was a little too worried that the zinc might go up in
smoke, and I ended up pulling the spoon out of the flame
periodically. Anyway, I finally grew impatient, so I whacked the
spoon upside down on my workboard, in an attempt to get the metal,
which at that point I mistakenly thought was unmelted, out of the
spoon. Now I found myself scrambling to scrape the rapidly freezing
metal into a single glob with the spoon. I had succeeded in turning
one half spoonfull of nuggets into a single nugget!

After this learning experience, I concluded that if I had just used a
more robust mold to begin with, it would have been more natural for me
to have banged the spoon against the mold, instead of on the
workboard. I broke my stone tile into two pieces, and then I looked
for voids. I didn't really expect to see any, but then I am no stone
expert either. I continued breaking it into about six pieces
altogether, each time looking for air pockets within the stone. I
found none. I assembled the stone into a mold, with the straight cut
edges towards the inside. Then I filled the spoon to the brim with
freash nuggets, and heated it again until the zinc itself was red hot,
and gave it a tap when I knocked it into the mold. It turned out
okay.

I have a web cam, though I will need to find the disc with the
software that goes with the camera. Anyway, I have been working the
arrowhead with a fine-toothed flat file, and it is looking good. It
could use a hot dip treatment I'm sure, but I don't have the ability
to do that just yet. The next thing I will do is to acquire a two
tablespoon capacity measuring spoon for the next melt, for which I
will make a bigger mold. Eventually, I suppose I will have to start
calling my casts "spear heads", I suppose. Oh yes, this is my first
cast ever. I am a happy camper.

Mike Mandaville
the Austin hill country
Willie Nelson land
Ads
  #2  
Old April 19th 09, 06:35 AM posted to rec.crafts.jewelry
Peter W. Rowe[_2_]
external usenet poster
 
Posts: 115
Default First Cast

On Sat, 18 Apr 2009 22:26:59 -0700, in rec.crafts.jewelry Muso
wrote:

I filled a one-tablespoon stainless
steel measuring spoon about half way full with zinc nuggets, and then
I heated the spoon with a propane torch. The torch made a red spot on
the side of the spoon, though the zinc did not seem to be melting.


Mike, it occurs to me to wonder if you're doing any research reading prior to
your experiments? If you had, you might have recognized that zinc, like lead,
like aluminum, or a number of other metals more reactive than gold or silver,
for oxide "dross" films quickly when melting. Even though the metal in the
spoon quickly melted, what you saw on the outside was a mess of zinc oxide. It
doesn't melt, so it completely hides what may be happening underneath to the
non-oxidized metal.

To some degree, this is unavoidable, since the grains/nuggets will already have
this on the surface, and when they melt, that rises to the top. Before pouring,
you'll want to brush off that mess so you're only pouring molten metal, not lots
of mixed in oxide crud too.

Another fix is to use a melting flux. Ordinary soft soldering acid flux, such
as plumbers use would do the trick just fine, And if you use a softer flame,
and actually hold the flame over the metal, the reducing atmospher of the flame
itself (the part of the flame past the inner blue cone, but still within the
glowing part of the flame, not way past where it's just very hot gases), that
part of the flame has little oxygen, so the metal stays cleaner during melting.

By the way, using clean zinc grain to begin with, unlike what you get from
murdering pennies, would drastically reduce the amount of oxide crud you have to
deal with... (grin)

Peter
  #3  
Old April 22nd 09, 08:26 AM posted to rec.crafts.jewelry
Muso
external usenet poster
 
Posts: 10
Default First Cast

On Apr 19, 12:35*am, Peter W. Rowe
wrote:
On Sat, 18 Apr 2009 22:26:59 -0700, in rec.crafts.jewelry Muso

wrote:
I filled a one-tablespoon stainless
steel measuring spoon about half way full with zinc nuggets, and then
I heated the spoon with a propane torch. *The torch made a red spot on
the side of the spoon, though the zinc did not seem to be melting.


Mike, it occurs to me to wonder if you're doing any research reading prior to
your experiments? *If you had, you might have recognized that zinc, like lead,
like aluminum, or a number of other metals more reactive than gold or silver,
for oxide "dross" films quickly when melting. *Even though the metal in the
spoon quickly melted, what you saw on the outside was a mess of zinc oxide. *It
doesn't melt, so it completely hides what may be happening underneath to the
non-oxidized metal. *


Hello again, Peter. I have the book "The Charcoal Foundry", by Dave
Gingery, and the book does mention about the dross. I was holding the
torch with my left hand, though, and the spoon with my right hand, and
I wasn't sure how much working time I had to work with, so I just put
the metal in the mold dross and all. I've decided to build a holder
for my torch, though, now that it is clear to me that such a holder
will be useful. I probably will build a holder for my new three-
tablespoon capacity stainless steel ladle, also.

To some degree, this is unavoidable, since the grains/nuggets will already have
this on the surface, and when they melt, that rises to the top. *Before pouring,
you'll want to brush off that mess so you're only pouring molten metal, not lots
of mixed in oxide crud too.


Yes, I worked on that arrow head for a long time with my file, but I
still ended up with some pits and cracks. I think that with practice,
though, I should be able to get much better results. I ended up with
a good functional arrow head, but from an appearance standpoint, not
so hot.

Another fix is to use a melting flux. * Ordinary soft soldering acid flux, such
as plumbers use would do the trick just fine, *And if you use a softer flame,
and actually hold the flame over the metal, the reducing atmospher of the flame
itself (the part of the flame past the inner blue cone, but still within the
glowing part of the flame, not way past where it's just very hot gases), that
part of the flame has little oxygen, so the metal stays cleaner during melting.


I think that my mother must have remembered me joking about Twenty
Mule Team Borax, because we now have some in the laundry room. I've
been melting outdoors after sundown, by the way, so I can see the
flame better, as well as the red glow from the grain and nuggets,
which I did seperate, by the way, just to see what I had. Gingery
covers the matter of an oxidizing verses a reducing atmosphere also.
Right now I'm long on theory, but short on experience.

By the way, using clean zinc grain to begin with, unlike what you get from
murdering pennies, would drastically reduce the amount of oxide crud you have to
deal with... *(grin)


Yes, in the long run I will need to find an alternative source for
zinc. Interestingly, I recently was able to recall purchasing some
zinc from a jeweler, which I don't recall ever melting, but I remember
finding some pieces of unmelted copper from pennies in the metal. I
had forgotten completely about this until recently.

Peter *


I bought some beeswax today, and some silica sand to add to my
fireclay. In retrospect, it looks like I already had some sand, but
it is so fine-grained that I thought it was clay. I now have three
hundred pounds of sand, and fifty pounds of fireclay. Later, I will
get some coarse silica sand, and some bentonite clay.

Mike Mandaville
Bee Cave, Texas
they are actually bat caves
we have millions of bats in the neighborhood
and plenty of buzzards
  #4  
Old April 22nd 09, 08:40 AM posted to rec.crafts.jewelry
Peter W. Rowe[_2_]
external usenet poster
 
Posts: 115
Default First Cast

On Wed, 22 Apr 2009 00:26:48 -0700, in rec.crafts.jewelry Muso
wrote:



Hello again, Peter. I have the book "The Charcoal Foundry", by Dave
Gingery, and the book does mention about the dross. I was holding the
torch with my left hand, though, and the spoon with my right hand, and
I wasn't sure how much working time I had to work with, so I just put
the metal in the mold dross and all. I've decided to build a holder
for my torch, though, now that it is clear to me that such a holder
will be useful. I probably will build a holder for my new three-
tablespoon capacity stainless steel ladle, also.


Larger quantities help. Also, as I've mentioned before, especially with your
fairly low tech melting/casting facilties, you'll have much better resuts with
tin based alloy, rather than zinc. That means, essentially, pewter, which
generally is essentially pure tin, with a trace of antimony an/or copper to
slightly harden it. melting temps are similar to zinc, and the cost is not very
different either, but it melts and casts a LOT more easily. It's routine for
those metalsmiths working with pewter to melt it in fairly informal equipment,
even down to just melting it in a tin can over a hot stove. (steel can.
Stainless seamless pot works better) can be cast into molds made of wood
(limited use, but it's a classic for pewter workers needing to make the cast
handles for pewter teapots and the like), or well dried plaster of paris (fine
for pewter, not good for higher melting metals, where you can use the similar
looking, but temperature resisting, casting investments used for lost wax
casting.), not to mention sand molds, or almost anything else you can dream up
that won't burn quickly. As I've mentioned before, one good source for white
metals for casting (or in sheet and wire), including but not limited to pewter,
is the Contenti company (www.contenti.com).


Yes, I worked on that arrow head for a long time with my file, but I
still ended up with some pits and cracks. I think that with practice,
though, I should be able to get much better results. I ended up with
a good functional arrow head, but from an appearance standpoint, not
so hot.


The zinc not only incorporated the mixed in cross, but also likely absorbed a
good deal of atmospheric gasses, which also leads to pits and pinholes galore.
Again, this is another area where pewter or other tine alloys are far superior.

As far as "functional", well, I'd assume you mean in terms of visual shape. I
doubt a zinc arrowhead would work so well at the end of an actual arrow. Too
soft...



I think that my mother must have remembered me joking about Twenty
Mule Team Borax, because we now have some in the laundry room.


20 mule team borax is a great way to buy the stuff cheap. But note that borax
is best as a flux for higher melting alloys, like brass, bronze, silver, gold,
etc. It isn't the right stuff for tin, zinc, or lead alloys. They melt at too
low a temp, before the borax becomes properly effective.

Right now I'm long on theory, but short on experience.


Books are a great way to start. So is actual experience, especially making
mistakes. Reading the books carefully, though, and not then ignoring what they
say, can help minimize the frequency and pain of the mistakes...


I bought some beeswax today, and some silica sand to add to my
fireclay. In retrospect, it looks like I already had some sand, but
it is so fine-grained that I thought it was clay. I now have three
hundred pounds of sand, and fifty pounds of fireclay. Later, I will
get some coarse silica sand, and some bentonite clay.


Sounds like you're on your way to doing large sculptural sized sand castings.
You might have to learn how to melt bronze at that rate... (grin)

Cheers

Peter Rowe

  #5  
Old April 23rd 09, 01:19 AM posted to rec.crafts.jewelry
ted frater
external usenet poster
 
Posts: 133
Default First Cast and subsequent casts

Muso wrote:
On Apr 19, 12:35 am, Peter W. Rowe
wrote:
On Sat, 18 Apr 2009 22:26:59 -0700, in rec.crafts.jewelry Muso

wrote:
I filled a one-tablespoon stainless
steel measuring spoon about half way full with zinc nuggets, and then
I heated the spoon with a propane torch. The torch made a red spot on
the side of the spoon, though the zinc did not seem to be melting.

Mike, it occurs to me to wonder if you're doing any research reading prior to
your experiments? If you had, you might have recognized that zinc, like lead,
like aluminum, or a number of other metals more reactive than gold or silver,
for oxide "dross" films quickly when melting. Even though the metal in the
spoon quickly melted, what you saw on the outside was a mess of zinc oxide. It
doesn't melt, so it completely hides what may be happening underneath to the
non-oxidized metal.


Hello again, Peter. I have the book "The Charcoal Foundry", by Dave
Gingery, and the book does mention about the dross. I was holding the
torch with my left hand, though, and the spoon with my right hand, and
I wasn't sure how much working time I had to work with, so I just put
the metal in the mold dross and all. I've decided to build a holder
for my torch, though, now that it is clear to me that such a holder
will be useful. I probably will build a holder for my new three-
tablespoon capacity stainless steel ladle, also.

To some degree, this is unavoidable, since the grains/nuggets will already have
this on the surface, and when they melt, that rises to the top. Before pouring,
you'll want to brush off that mess so you're only pouring molten metal, not lots
of mixed in oxide crud too.


Yes, I worked on that arrow head for a long time with my file, but I
still ended up with some pits and cracks. I think that with practice,
though, I should be able to get much better results. I ended up with
a good functional arrow head, but from an appearance standpoint, not
so hot.

Another fix is to use a melting flux. Ordinary soft soldering acid flux, such
as plumbers use would do the trick just fine, And if you use a softer flame,
and actually hold the flame over the metal, the reducing atmospher of the flame
itself (the part of the flame past the inner blue cone, but still within the
glowing part of the flame, not way past where it's just very hot gases), that
part of the flame has little oxygen, so the metal stays cleaner during melting.


I think that my mother must have remembered me joking about Twenty
Mule Team Borax, because we now have some in the laundry room. I've
been melting outdoors after sundown, by the way, so I can see the
flame better, as well as the red glow from the grain and nuggets,
which I did seperate, by the way, just to see what I had. Gingery
covers the matter of an oxidizing verses a reducing atmosphere also.
Right now I'm long on theory, but short on experience.

By the way, using clean zinc grain to begin with, unlike what you get from
murdering pennies, would drastically reduce the amount of oxide crud you have to
deal with... (grin)


Yes, in the long run I will need to find an alternative source for
zinc. Interestingly, I recently was able to recall purchasing some
zinc from a jeweler, which I don't recall ever melting, but I remember
finding some pieces of unmelted copper from pennies in the metal. I
had forgotten completely about this until recently.

Peter


I bought some beeswax today, and some silica sand to add to my
fireclay. In retrospect, it looks like I already had some sand, but
it is so fine-grained that I thought it was clay. I now have three
hundred pounds of sand, and fifty pounds of fireclay. Later, I will
get some coarse silica sand, and some bentonite clay.

Mike Mandaville
Bee Cave, Texas
they are actually bat caves
we have millions of bats in the neighborhood
and plenty of buzzards


Hi Misco,
Good to see your making progress.
Are your arrow heads for use? or just decorative?
A couple of suggestions for you.

1. Re zinc supplies.
Are you near any scrap merchants?
because they may have the following,
Printers type
Zinc rainwater goods ie guttering down pipes
I understand that in the S USA zinc has long been used for this type of
work.
Plumbers solder, the type used to join lead pipes together.
This is 40% tin and 60% lead.
Good casting metal.
And die cast car fittings. door handles etc.

2. Re melting generally, with a propane torch.
You need to build a 4 legged stand with a propane burner under the top
frame.
This can be 6 in by 6in with a s/steel mesh say 1in sq by 1/8 thich
wires with a hole cut in the middle to hold a cast iron or stainless
steel long handled half round bowl. thats what Ive used for a project
recently. You will also need an outrigger support for the handle. When
you have say 1 to 2lbs of metal melting in the bowl its gets unstable
and heavy.

the propane torch is 2in dia fed from a regulator on a 47kg propane
tank. We call them cylinders here in the UK.
What is important about this set up is that a big flame will heat the
bowl from the underside AND from the top. You try it,
As the flame encloses the whole of the bowl,and the metal , it curls
over the bowl top and down into and onto the metal, so reducing the
oxidation of the melt.
Hope this helps
keep us posted
Ted
Dorset
UK












  #6  
Old April 25th 09, 05:37 AM posted to rec.crafts.jewelry
Muso
external usenet poster
 
Posts: 10
Default First Cast and subsequent casts

On Apr 22, 7:19*pm, Ted Frater wrote:
Muso wrote:
On Apr 19, 12:35 am, Peter W. Rowe
wrote:
On Sat, 18 Apr 2009 22:26:59 -0700, in rec.crafts.jewelry Muso


wrote:
I filled a one-tablespoon stainless
steel measuring spoon about half way full with zinc nuggets, and then
I heated the spoon with a propane torch. *The torch made a red spot on
the side of the spoon, though the zinc did not seem to be melting.
Mike, it occurs to me to wonder if you're doing any research reading prior to
your experiments? *If you had, you might have recognized that zinc, like lead,
like aluminum, or a number of other metals more reactive than gold or silver,
for oxide "dross" films quickly when melting. *Even though the metal in the
spoon quickly melted, what you saw on the outside was a mess of zinc oxide. *It
doesn't melt, so it completely hides what may be happening underneath to the
non-oxidized metal. *


Hello again, Peter. *I have the book "The Charcoal Foundry", by Dave
Gingery, and the book does mention about the dross. *I was holding the
torch with my left hand, though, and the spoon with my right hand, and
I wasn't sure how much working time I had to work with, so I just put
the metal in the mold dross and all. *I've decided to build a holder
for my torch, though, now that it is clear to me that such a holder
will be useful. *I probably will build a holder for my new three-
tablespoon capacity stainless steel ladle, also.


To some degree, this is unavoidable, since the grains/nuggets will already have
this on the surface, and when they melt, that rises to the top. *Before pouring,
you'll want to brush off that mess so you're only pouring molten metal, not lots
of mixed in oxide crud too.


Yes, I worked on that arrow head for a long time with my file, but I
still ended up with some pits and cracks. *I think that with practice,
though, I should be able to get much better results. *I ended up with
a good functional arrow head, but from an appearance standpoint, not
so hot.


Another fix is to use a melting flux. * Ordinary soft soldering acid flux, such
as plumbers use would do the trick just fine, *And if you use a softer flame,
and actually hold the flame over the metal, the reducing atmospher of the flame
itself (the part of the flame past the inner blue cone, but still within the
glowing part of the flame, not way past where it's just very hot gases), that
part of the flame has little oxygen, so the metal stays cleaner during melting.


I think that my mother must have remembered me joking about Twenty
Mule Team Borax, because we now have some in the laundry room. *I've
been melting outdoors after sundown, by the way, so I can see the
flame better, as well as the red glow from the grain and nuggets,
which I did seperate, by the way, just to see what I had. *Gingery
covers the matter of an oxidizing verses a reducing atmosphere also.
*Right now I'm long on theory, but short on experience.


By the way, using clean zinc grain to begin with, unlike what you get from
murdering pennies, would drastically reduce the amount of oxide crud you have to
deal with... *(grin)


Yes, in the long run I will need to find an alternative source for
zinc. *Interestingly, I recently was able to recall purchasing some
zinc from a jeweler, which I don't recall ever melting, but I remember
finding some pieces of unmelted copper from pennies in the metal. *I
had forgotten completely about this until recently.


Peter *


I bought some beeswax today, and some silica sand to add to my
fireclay. *In retrospect, it looks like I already had some sand, but
it is so fine-grained that I thought it was clay. *I now have three
hundred pounds of sand, and fifty pounds of fireclay. *Later, I will
get some coarse silica sand, and some bentonite clay.


Mike Mandaville
Bee Cave, Texas
they are actually bat caves
we have millions of bats in the neighborhood
and plenty of buzzards


Hi Misco,
Good to see your making progress.
Are your arrow heads for use?


Hello again, Ted. In retrospect, my first arrowhead was only for
casting practice. The reason I say this is because since I only have
just so much zinc to melt down now, I will be melting down my first
arrowhead to become part of my first spearhead, for which I have now
carved the wax model.

or just decorative?
A couple of suggestions for you.

* 1. Re zinc supplies.
Are you near any scrap merchants?


Yes, and I have been studying yje metal scrap market.

* because they may have the following,
Printers type


I bought twenty-five pounds of burnt line-o-type metal locally.

Zinc rainwater goods ie guttering *down pipes
I understand that in the S USA zinc has long been used for this type of
work.
Plumbers solder, the type used to join lead pipes together.
* This is 40% tin and 60% lead.
* Good casting metal.
And die cast car fittings. door handles etc.


2. Re melting generally, with a propane torch.
You need to build a 4 legged stand with a propane burner under the top
frame.
* This can be 6 in by 6in with a s/steel mesh say 1in *sq by 1/8 thich
wires with a hole cut in the middle to hold a cast iron or stainless
steel long handled half round bowl. thats what Ive used for a project
recently. You will also need an outrigger support for the handle. When
you have say 1 to 2lbs of metal melting in the bowl its gets unstable
and heavy.


I might be moving to yet a third ladle after my first melt with the
second. I will be building such a stand eventually, though, one way
or another. I also found a small charcoal brazier which I will be
getting eventually.

* the propane torch is 2in dia fed from a regulator on a 47kg propane
tank. We call them cylinders here in the UK.
What is important about this set up is that a big flame will heat the
bowl from the underside AND from the top. You try it,
As the flame encloses the whole of the bowl,and the metal , it curls
over the bowl top and down into and onto the metal, so reducing the
oxidation of the melt.
Hope this helps


Yes, it does. I probably will eventually be getting a swirl torch.

keep us posted


I certainly will.

Ted
* Dorset
* UK


When it comes to metalworking, you Brits know your stuff.

  #7  
Old April 26th 09, 06:16 PM posted to rec.crafts.jewelry
Muso
external usenet poster
 
Posts: 10
Default First Cast

On Apr 22, 12:40*am, Peter W. Rowe
wrote:
On Wed, 22 Apr 2009 00:26:48 -0700, in rec.crafts.jewelry Muso

wrote:

Hello again, Peter. *I have the book "The Charcoal Foundry", by Dave
Gingery, and the book does mention about the dross. *I was holding the
torch with my left hand, though, and the spoon with my right hand, and
I wasn't sure how much working time I had to work with, so I just put
the metal in the mold dross and all. *I've decided to build a holder
for my torch, though, now that it is clear to me that such a holder
will be useful. *I probably will build a holder for my new three-
tablespoon capacity stainless steel ladle, also.


Larger quantities help. *Also, as I've mentioned before, especially with your
fairly low tech melting/casting facilties, you'll have much better resuts with
tin based alloy, rather than zinc. *That means, essentially, pewter, which
generally is essentially pure tin, with a trace of antimony an/or copper to
slightly harden it. *melting temps are similar to zinc, and the cost is not very
different either, but it melts and casts a LOT more easily. *It's routine for
those metalsmiths working with pewter to melt it in fairly informal equipment,
even down to just melting it in a tin can over a hot stove. *(steel can.
Stainless seamless pot works better) *can be cast into molds made of wood
(limited use, but it's a classic for pewter workers needing to make the cast
handles for pewter teapots and the like), or well dried plaster of paris (fine
for pewter, not good for higher melting metals, where you can use the similar
looking, but temperature resisting, casting investments used for lost wax
casting.), not to mention sand molds, or almost anything else you can dream up
that won't burn quickly. * As I've mentioned before, one good source for white
metals for casting (or in sheet and wire), including but not limited to pewter,
is the Contenti company (www.contenti.com).


Hello again, Peter. As you know, I like to use scrap metal, and if I
wanted a refined metal, I would do the job myself. My point of view
about this has not changed. I don't expect that I would find very
much scrap tin around, though, since tin is outrageously expensive
anyway. Scrap zinc is available, though, and for tool making zinc is
better than tin regardless.

Yes, I worked on that arrow head for a long time with my file, but I
still ended up with some pits and cracks. *I think that with practice,
though, I should be able to get much better results. *I ended up with
a good functional arrow head, but from an appearance standpoint, not
so hot.


The zinc not only incorporated the mixed in cross, but also likely absorbed a
good deal of atmospheric gasses, which also leads to pits and pinholes galore.
Again, this is another area where pewter or other tine alloys are far superior


Peter, that you would consider pewter superior to zinc for an
arrowhead is amusing to me. I see no reason why a functional
arrowhead could not be made from pewter, but that such an arrowhead
should be superior to zinc? I don't think so.

As far as "functional", well, I'd assume you mean in terms of visual shape. *I
doubt a zinc arrowhead would work so well at the end of an actual arrow.


But pewter would? You have offered no reason that I can see.

*Too soft...


And pewter is harder than zinc? I don't follow your reasoning.

I think that my mother must have remembered me joking about Twenty
Mule Team Borax, because we now have some in the laundry room.


20 mule team borax is a great way to buy the stuff cheap. *But note that borax
is best as a flux for higher melting alloys, like brass, bronze, silver, gold,
etc. *It isn't the right stuff for tin, zinc, or lead alloys.


Okay, well, I'll remember that then.

*They melt at too
low a temp, before the borax becomes properly effective.

Right now I'm long on theory, but short on experience.


Books are a great way to start. *So is actual experience, especially making
mistakes. *Reading the books carefully, though, and not then ignoring what they
say, can help minimize the frequency and pain of the mistakes...


My "mistakes" have not been painful. The first cast was not meant to
be perfect, though I could easily make it that way. I'm just ready to
move on. Today I bought some wood and string to weigh out the sand to
make the mold to cast my first spear head.

I bought some beeswax today, and some silica sand to add to my
fireclay. *In retrospect, it looks like I already had some sand, but
it is so fine-grained that I thought it was clay. *I now have three
hundred pounds of sand, and fifty pounds of fireclay. *Later, I will
get some coarse silica sand, and some bentonite clay.


Sounds like you're on your way to doing large sculptural sized sand castings.
You might have to learn how to melt bronze at that rate... (grin)

Cheers

Peter Rowe


Actually, the quantity is misleading. The sand is so fine-grained (60
mesh to 80 mesh) that I was unsure that it was even sand at all. I
could have just added water, of course, but, anyway, when I went back
for another bag, the worker threw in an extra third bag, which was
just as difficult to unload as the second. Anyway, I am making
progress, and I am happy. I will not be moving on to brass for
awhile, though I am interested in lost wax.

Mike Mandaville
Bee Cave, Texas
  #8  
Old April 26th 09, 06:34 PM posted to rec.crafts.jewelry
Peter W. Rowe[_2_]
external usenet poster
 
Posts: 115
Default First Cast

On Sun, 26 Apr 2009 10:16:05 -0700, in rec.crafts.jewelry Muso
wrote:



Hello again, Peter. As you know, I like to use scrap metal, and if I
wanted a refined metal, I would do the job myself. My point of view
about this has not changed. I don't expect that I would find very
much scrap tin around, though, since tin is outrageously expensive
anyway. Scrap zinc is available, though, and for tool making zinc is
better than tin regardless.


Not being a toolmaker, at least in that sense (when I'm making tools for my own
use, it's usually from steel), I'll take your word for it. But from curiosity,
why?


Peter, that you would consider pewter superior to zinc for an
arrowhead is amusing to me. I see no reason why a functional
arrowhead could not be made from pewter, but that such an arrowhead
should be superior to zinc? I don't think so.


I didn't say it would be superior to zinc as an arrowhead. I said the pewter
would be easier to get a good, porosity free casting from. That's all.
Remember, my approach to this is to objects used as decorative items, so the
quality of the casting affects the visual appeal. That's the main focus of my
statement.


As far as "functional", well, I'd assume you mean in terms of visual shape. *I
doubt a zinc arrowhead would work so well at the end of an actual arrow.


But pewter would? You have offered no reason that I can see.


Again, no I didn't mean that pewter would make a better actual arrowhead. I
meant that making a decorative arrowhead, or spearpoint, or whatever, would be
easier in pewter, since you get a better casting. Frankly, I'd be surprised if
either pewter or zinc could produce a usable actual arrowhead in any case. I
might be wrong, of course, but I'd expect neither metal to be strong enough to
withstand the sorts of impact stresses an arrowhead would need. You are right
that pewter is likely to be softer than zinc, but I'd expect zinc to be too soft
for a good arrowhead as well. Thus I assume the aim is for a decorative item.
However, I'm not all that experienced in either making arrowheads, or functional
items in zinc, so perhaps I'm wrong, and you can go hunting or target shooting
with zinc arrowheads just fine. If so, have fun!

*Too soft...


And pewter is harder than zinc? I don't follow your reasoning.


Pewter is not harder than zinc. In fact, it has the unusual property of not
work hardening when you manually work it. It actually gets softer as you work
it. But as I said above, my assumption is that BOTH metals are too soft for a
good arrowhead. I might be wrong, of course. I make jewelry, not weapons, for
the most part. The little knifemaking I've done used steels, not zinc...


My "mistakes" have not been painful. The first cast was not meant to
be perfect, though I could easily make it that way. I'm just ready to
move on. Today I bought some wood and string to weigh out the sand to
make the mold to cast my first spear head.


Mistakes are not automatically painful, or even a bad thing. They're an
especially effective way to learn about not just what not to do, but why not to
do it. The pain comes from repeating mistakes one should have learned from, or
making mistakes that could have been easily avoided. Or from making mistakes
that cost an undue amount of cash... But again, experimenting and working
things out for yourself are a fine and recommended way to learn. Far superior,
I think, to just following instructions and learning a sequence of operations by
rote, without understanding them. Please, by all means, continue to
experiement. I applaud your efforts. However, do try to avoid spending too
much time re-inventing the wheel...


Actually, the quantity is misleading. The sand is so fine-grained (60
mesh to 80 mesh) that I was unsure that it was even sand at all. I
could have just added water, of course, but, anyway, when I went back
for another bag, the worker threw in an extra third bag, which was
just as difficult to unload as the second. Anyway, I am making
progress, and I am happy. I will not be moving on to brass for
awhile, though I am interested in lost wax.


That sand sounds a bit like the very fine grained sand packaged in a somewhat
pricey little sand casting kit called "Delft clay" casting sand. Comes with a
little mold kit. That sand too, looks very very fine grained. I think it's an
oil tempered sand, but I'm not sure. Fairly easy to use, but whomever is
repackaging it as "Delft clay" instead of it's original name (I've been told,
but don't know, that it's the same as somethign called petrobond...) is no doubt
making a good deal of cash off of jewelers not familier with commercial sand
casting materials...

Cheers

Peter
  #9  
Old April 27th 09, 12:13 AM posted to rec.crafts.jewelry
Muso
external usenet poster
 
Posts: 10
Default First Cast

On Apr 26, 10:34*am, Peter W. Rowe
wrote:
On Sun, 26 Apr 2009 10:16:05 -0700, in rec.crafts.jewelry Muso

wrote:

Hello again, Peter. *As you know, I like to use scrap metal, and if I
wanted a refined metal, I would do the job myself. *My point of view
about this has not changed. *I don't expect that I would find very
much scrap tin around, though, since tin is outrageously expensive
anyway. *Scrap zinc is available, though, and for tool making zinc is
better than tin regardless.


Not being a toolmaker, at least in that sense (when I'm making tools for my own
use, it's usually from steel), I'll take your word for it. *But from curiosity,
why?


Hello again, Peter. On the hardness scale, I confess that I do not
know where either tin or zinc lie. Since I would not want to be at
the receiving end of an arrowhead made from either tin or zinc,
though, I will not bother to look it up just yet. I would like very
much to know about your steel toolmaking experience. I can buy small
pieces of stainless steel at my local hobby shop, by the way.

Peter, that you would consider pewter superior to zinc for an
arrowhead is amusing to me. *I see no reason why a functional
arrowhead could not be made from pewter, but that such an arrowhead
should be superior to zinc? *I don't think so.


I didn't say it would be superior to zinc as an arrowhead. *I said the pewter
would be easier to get a good, porosity free casting from. *That's all.
Remember, my approach to this is to objects used as decorative items, so the
quality of the casting affects the visual appeal. *That's the main focus of my
statement.


Again, I have full confidence that a tin arrowhead would be very
deadly, to the degree that I will not even bother to test the idea.

As far as "functional", well, I'd assume you mean in terms of visual shape. *I
doubt a zinc arrowhead would work so well at the end of an actual arrow.


But pewter would? *You have offered no reason that I can see.


Again, no I didn't mean that pewter would make a better actual arrowhead. *I
meant that making a decorative arrowhead, or spearpoint, or whatever, would be
easier in pewter, since you get a better casting. *Frankly, I'd be surprised if
either pewter or zinc could produce a usable actual arrowhead in any case. *I
might be wrong, of course, but I'd expect neither metal to *be strong enough to
withstand the sorts of impact stresses an arrowhead would need. *You are right
that pewter is likely to be softer than zinc, but I'd expect zinc to be too soft
for a good arrowhead as well. *Thus I assume the aim is for a decorative item.
However, I'm not all that experienced in either making arrowheads, or functional
items in zinc, so perhaps I'm wrong, and you can go hunting or target shooting
with zinc arrowheads just fine. *If so, have fun!


Peter, I have thought about building a crossbow for target practice,
and I think I might do so eventually. Of course, a spear could be
launched by a similar larger aparatus. In fact, I remember a
television program about an enormous crossbow.

*Too soft...


And pewter is harder than zinc? *I don't follow your reasoning.


Pewter is not harder than zinc. *In fact, it has the unusual property of not
work hardening when you manually work it. *It actually gets softer as you work
it. *But as I said above, my assumption is that BOTH metals are too soft for a
good arrowhead. *I might be wrong, of course. *I make jewelry, not weapons, for
the most part. *The little knifemaking I've done used steels, not zinc...


Here we go again, Peter. I would like very much to hear about your
experience in working with steel to make tools and knives. I have no
experience in either of these areas, by the way.

My "mistakes" have not been painful. *The first cast was not meant to
be perfect, though I could easily make it that way. *I'm just ready to
move on. *Today I bought some wood and string to weigh out the sand to
make the mold to cast my first spear head.


Mistakes are not automatically painful, or even a bad thing. *They're an
especially effective way to learn about not just what not to do, but why not to
do it.


Peter, I see that you know about the ladies! Just kidding :-)

*The pain comes from repeating mistakes one should have learned from,
or
making mistakes that could have been easily avoided. * Or from making mistakes
that cost an undue amount of cash... * But again, experimenting and working
things out for yourself are a fine and recommended way to learn. *Far superior,
I think, to just following instructions and learning a sequence of operations by
rote, without understanding them. * Please, by all means, continue to
experiement. *I applaud your efforts. *However, do try to avoid spending too
much time re-inventing the wheel...


Nowadays, all of Detroit is bragging about thirty miles per gallon.
Perhaps Detroit should "re-invent" the Messerschmitt, which could get
eighty miles per gallon.

Actually, the quantity is misleading. *The sand is so fine-grained (60
mesh to 80 mesh) that I was unsure that it was even sand at all. *I
could have just added water, of course, but, anyway, when I went back
for another bag, the worker threw in an extra third bag, which was
just as difficult to unload as the second. *Anyway, I am making
progress, and I am happy. *I will not be moving on to brass for
awhile, though I am interested in lost wax.


That sand sounds a bit like the very fine grained sand packaged in a somewhat
pricey little sand casting kit called "Delft clay" casting sand. *Comes with a
little mold kit. *That sand too, looks very very fine grained. *I think it's an
oil tempered sand, but I'm not sure. *Fairly easy to use, but whomever is
repackaging it as "Delft clay" instead of it's original name (I've been told,
but don't know, that it's the same as somethign called petrobond...) is no doubt
making a good deal of cash off of jewelers not familier with commercial sand
casting materials...

Cheers

Peter


Yes, the Gingery fellows rave about Petrobond, though to be used
effectively, it needs to be muled, and the price of feeding and
housing a mule nowadays is very expensive. No, seriously, iron
casting has to be done with water-based sand anyway, otherwise known
as green sand, so I will be staying with green sand.

Cheers

Mike
  #10  
Old April 27th 09, 12:38 AM posted to rec.crafts.jewelry
Peter W. Rowe[_2_]
external usenet poster
 
Posts: 115
Default First Cast

On Sun, 26 Apr 2009 16:13:06 -0700, in rec.crafts.jewelry Muso
wrote:

On Apr 26, 10:34*am, Peter W. Rowe
wrote:
On Sun, 26 Apr 2009 10:16:05 -0700, in rec.crafts.jewelry Muso
wrote:



Hello again, Peter. On the hardness scale, I confess that I do not
know where either tin or zinc lie. Since I would not want to be at
the receiving end of an arrowhead made from either tin or zinc,
though, I will not bother to look it up just yet. I would like very
much to know about your steel toolmaking experience. I can buy small
pieces of stainless steel at my local hobby shop, by the way.


I wouldn't wish to be hit with an arrowhead of any kind, frankly. But were I to
be making arrows, I'd wish to make them so they could be fired more than once or
twice. Though I've not tested this, I'd guess that you'd only get a very
limited number of uses (maybe only a single use) from arrowheads made of such
metals before they either were broken on impact, or warped, bent, and otherwise
made unusable. Again, I might be wrong, but that's what I'd expect...


Again, I have full confidence that a tin arrowhead would be very
deadly, to the degree that I will not even bother to test the idea.


:-)



Peter, I have thought about building a crossbow for target practice,
and I think I might do so eventually. Of course, a spear could be
launched by a similar larger aparatus. In fact, I remember a
television program about an enormous crossbow.


yeah, I remember that show. A Roman seige weapon, as I recall, using taut wound
ropes for the springs... Discovery channel or maybe Military channel, I
think.. Same show at various times has built trebuchets, and tried to duplicate
greek fire, among other ancient weapons


Here we go again, Peter. I would like very much to hear about your
experience in working with steel to make tools and knives. I have no
experience in either of these areas, by the way.


Steels are fun to work with. I'm not making my own steel, mind you, just making
things from it. As a goldsmith, one often finds the need for things like stamps
or punches or small forming tools to suit a given task. One can either modify
an existing tool or make one from a piece of scrap steel. Old Files, for
example, are good quality steel. So is commercially made drill rod, or in a
pinch, even concrete nails make decent small punches when needed. You need the
usual sorts of files, abrasives, and other jewelers tools to work and shape
steel like any metal. If it's hardened, you need to anneal it first in most
cases, then reharden and temper it after, if it needs it. Steels offer another
easy way to shape them, by heating red hot, at which time they become very
plastic, and easily shaped and formed with a hammer. That's basic blacksmithing
of course, and at this sort of basic level, needs little in the way of skill or
equipment. A torch to heat the metal with, a hammer, and something to hammer
against. Anvils are nice, but not necessary for small work. For other sorts of
tools, some machining may be required. Again, steels are among the most
machineable metals. Commerciually available cutting tools, from files to lathe
tools, generally are designed off the shelf for cutting steels, and any decent
machine tool, from lathes, to drill presses, mills, shapers, etc, can be used.
The big limitation of steels, compared to various non-ferrous metals we commonly
use, is the melting point, which often means that actually melting steels and
pouring ingots or castings, is usually beyond the average home workshop. Though
it Can be done if one really needs to. Steels themselves are usually too high
melting for home equipment, but cast iron melts a little lower, and with effort,
a homebuilt foundry furnace like the Gingery can be made to do it. Not easy,
though. That is the reason so many home workshop metal workers needing a
casting do it in aluminum, or like you, zinc based metals. If the require part
needs some rigidity, but not high strength (which can be compensated for many
times simply by making the part bigger and thicker so the zinc is strong
enough), then zinc may be just fine. Personally, when I need such parts, I'm
more comfortable using bronze, but that's just because I've got the stuff, and
have more experience with it. And I know it's strong enough, whereas the zinc
based alloys might not be, depending on what I need to make. Yes, I know it's
more costly than zinc.


Peter, I see that you know about the ladies! Just kidding :-)


Hah. I wish. Single. Never married. Some would say that's good. I find it a
bit lonely. But I have cats...


Yes, the Gingery fellows rave about Petrobond, though to be used
effectively, it needs to be muled, and the price of feeding and
housing a mule nowadays is very expensive. No, seriously, iron
casting has to be done with water-based sand anyway, otherwise known
as green sand, so I will be staying with green sand.


The advantage of oil tempered sand is simply that it doesn't dry out. (duh.)
Green sand needs a bit more working to make it ready to use, since the water
evaporates. that's just as much trouble as preparing petrobond, in my
experience. But note that I've only used sand casting for small items, with
small molds. At that size, working the sand to prepare it, of either type, is
simple.

So are you saying you're planning to try and cast iron? How are you going to
melt it? That's a whole lot hotter than your zinc, or for that matter, hotter
than any of the metals I normally melt and cast, with the exception of platinum.
And Handling those temps is not trivial...

Peter
 




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