Casting Ingots

I have a double sided ingot mold, plate one side and round rod the
other. I have tried using soot and oil and I always have a little
crust of gold on tapered spout. I warn my ingot mold, probably
somewhere about 600 or 700 degrees. How can I stop the gold from
sticking? New ingot mold?

Richard Hart G.G.
Denver, Co.

Hello Richard,

keep you flame during the poor procedure on the crucible aswell as
on your outlet. As far as I understand your problem, the temperature
of your gold is dropping during your poor leaving that crust as a
result.

Enjoy and have fun
Pedro

I have a double sided ingot mold, plate one side and round rod the
other. I have tried using soot and oil and I always have a little
crust of gold on tapered spout. I warn my ingot mold, probably
somewhere about 600 or 700 degrees. How can I stop the gold from
sticking? New ingot mold? 

Wash all the oil off, use alcohol too to be assured there’s no more
oil. Wire brush (steel) the surfaces and only coat with soot.

If you’re talking about the thin fins that sometimes develop, I use
a belt sander for those.

Hi Richard,

Pick up some Delft clay to make your ingots.

  1. You don’t need to warm the mould, just make the shape and pour
    the metal

  2. You can make any shaped sheet or ingot you want

  3. Thinner sheet and ingots than steel moulds, and really clean

  4. Quick reset time, so if you bugger it up you can go again
    straight away

  5. Rolling the ingot/sheet is a joy

Now the negatives :-

  1. stinks
  2. fairly expensive

Regards Charles A.

I have what sounds like the same mold and I oil mine, Richard. I use
Three-In-One or similar light machine oil and use just enough to wet
the surface where the metal will come in contact. Warm up until the
oil smokes (maybe 600 degrees? hotter for white gold), and pour it.
Too much oil and you can get gas holes. Works a whole lot better
than soot, for me anyway.

Hope this helps you.
Dave Phelps

Hello Richard,

Check out my blog, I have a post specifically about this
http://www.ganoksin.com/gnkurl/p3

I too had the same sticking problems and after using this technique
the ingots came out smooth, only requiring some seam touch up prior
to drawing or rolling.

I hope this helps
Kenneth

Try putting a layer of soot ( pure black carbon) on the ingot mold.
I use the Little Torch, just turn on the acetylene and let the sooty
flame coat the ingot mold. If you are using an acetylene/air torch,
cut off the air supply on the torch tip and let the sooty flame coat
the mold. I do that to my molds and the metals do not stick to the
iron.

Hope that helps.
Joy
www.joyraskin.com

Delft sand is otherwise called Petrobond, available here in the UK
at a much more reasonable price.

http://www.ganoksin.com/gnkurl/pb

they also do other weird and interesting stuff such as polymorph.

regards,
Tim

Hi Tim,

Oil bonded sand is similar to Delft clay, but usually the sand is
foundry quality casting sand, and the grains are quite coarse.
Petrobond, and Petrobond II are additives to sand, for sand casting.

If you want to have a fairly grainy casting then buying oil bonded
sand would give you those results, and you can get a better price by
approaching a nonferrous metal foundry and asking if they can spare
a bucket of sand… I bought some and it cost me $30 for a 20kg
bucket of petrodond II oil bonded sand.

The casting lists I’m on are more DIY then I am, in that they like
to mull their own sand, but to do this you need a muller, and $30 is
less hassle.

Delft clay is a finer product and produces superior results to oil
bonded foundry sand.

You pay for fineness.

Kindest regards Charles A.

Delft sand is otherwise called Petrobond, available here in the UK
at a much more reasonable price. 

Tim, Petrobond can refer to a product that is not even close to the
Delft sand system as sold through Rio. I went to my local casting
supplier and came away with a 1kg sample of it. It’s very sandy, in
fact compared to Delft Petrobond is gritty, and it loses its
structure easily, and smells of both alcohol and oil. The company I
dealt with got it from an Australian supplier. So recommending
Petrobond might need some clarification.

Brian
Auckland
New Zealand
www.adam.co.nz

Delft clay is a finer product and produces superior results to oil
bond ed foundry sand. 

A foundryman told me that he used a low grade sand for the bulk of
the mould, and then a thin layer of high grade delft clay on top, to
improve the surface quality of the casting.

Jamie Hall
http://primitive.ganoksin.com

A foundryman told me that he used a low grade sand for the bulk of
the mould, and then a thin layer of high grade delft clay on top,
to improve the surface quality of the casting. 

That’d work, never thought of that… cool bananas. Thanks CIA