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sandcasting - how?

updated thu 6 may 04

 

Hendrix, Taylor J. on tue 4 may 04


Hehe,

I remember making sandcasts in highschool shop. Not difficult at all,
but then my memory about childhood is almost nonexistant. Could be a
little rose-colored memory glasses thing going on here. I do remember
taking my project home and shooting it with dad's staple gun: I was
hyper critical of my work back then.

I hear David Hendley makes his own sand out of old road signs and ground
up firebrick.

Taylor
Waco, Texas, USA
http://www3.baylor.edu/~Taylor_Hendrix/tjpots.htm

-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Fredrick
Paget
Sent: Tuesday, May 04, 2004 4:56 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: sandcasting - how?


...

The mold is made in a container that the foundry uses - I think it
was called a flask. The foundry sand is a barely damp mixture of
sand, coal dust, and clay, among other things. It is pounded into the
mold over the model using a special technique and tools that you need
to be trained to use. The sprue and riser are added in the other half
of the flask and the models are pulled out and the mold closed up.
and the flask is poured with molten metal. After cooling the casting
is taken out of the sand.

...

Patricia Gilmartin on tue 4 may 04


I am interesting in making a sand-cast copy of one of my bas reliefs.
Height of relief about 1.5 in.
Can anyone offer hints about making the sand mold? What kind of sand?
How to press the relief image into the sand? Mistakes to avoid? Any
advice will be appreciated.

Fredrick Paget on tue 4 may 04


>I am interesting in making a sand-cast copy of one of my bas reliefs.
>Height of relief about 1.5 in.
>Can anyone offer hints about making the sand mold? What kind of sand?
>How to press the relief image into the sand? Mistakes to avoid? Any
>advice will be appreciated.



All you have to do is make a good model and take it to a foundry.
The model needs 6 degrees of draft so it can be pulled out of the
sand in a straight pull. They make the mold.

Many years ago I took a required one unit course (four hours a week
for one quarter) in foundry at Engineering school so my memory is a
bit hazy. But here goes: (correct me if this is all out of date and
wrong now).

The mold is made in a container that the foundry uses - I think it
was called a flask. The foundry sand is a barely damp mixture of
sand, coal dust, and clay, among other things. It is pounded into the
mold over the model using a special technique and tools that you need
to be trained to use. The sprue and riser are added in the other half
of the flask and the models are pulled out and the mold closed up.
and the flask is poured with molten metal. After cooling the casting
is taken out of the sand.

Then there is a lot of cutting and grinding and polishing to get it
into a finished item.
This is not a do it yourself project. You need training, and a lot of
special equipment.

Fred
--
From Fred Paget, Marin County, California, USA
fredrick@well.com

pdp1@EARTHLINK.NET on tue 4 may 04


Hi Fred, Patricia,


Yup...


Too, one does well to obtain a clear written aggreement with
the Fundry, as to the cost as well as the grade of sand they
shall use.

They all have 'fine' sands as may be used, where little or
even no subsequent finishing would be needed, but for the
sprue's nubs, and, they have a way of promising that, then
forgetting, then getting 'pouty' if one bring it up.

'Draft' indeed, being the angle of the form's amenibility to
being removed from the Sand without hurting the sides of the
impression it is supposed to leave...


Too, one may easily make Moulds of a refractory Plaster, and
thence at 'low' heats, cast things in various Pewters,
Brittiannia Metals, Babbett or the likes, as fill out minute
details nicely, as well as flow well.

I imagine one may as well, with a little study, make a nice
enough refractory Plaster mould for a foundry to use on
one's behalf, for a Brass or Bronze casting...

Most foundrys do not enjoy haveing to deal with one-off sand
Castings, as it too much resemble 'Work'...while prefering
fall-boards as are lain across the flask, or in effect,
between the flasks, for the subsequent Sand pounding rituals
to ensue...and having one or multiple entities on
them...with all due and appropriate chimneys or what already
in the pattern...alleviating the chore of hand-scrapeing the
gas vents and channels for the Metal's entry and so on...


Phil
el ve

----- Original Message -----
From: "Fredrick Paget"

> >I am interesting in making a sand-cast copy of one of my
bas reliefs.
> >Height of relief about 1.5 in.
> >Can anyone offer hints about making the sand mold? What
kind of sand?
> >How to press the relief image into the sand? Mistakes to
avoid? Any
> >advice will be appreciated.
>
>
>
> All you have to do is make a good model and take it to a
foundry.
> The model needs 6 degrees of draft so it can be pulled out
of the
> sand in a straight pull. They make the mold.
>
> Many years ago I took a required one unit course (four
hours a week
> for one quarter) in foundry at Engineering school so my
memory is a
> bit hazy. But here goes: (correct me if this is all out of
date and
> wrong now).
>
> The mold is made in a container that the foundry uses -
I think it
> was called a flask. The foundry sand is a barely damp
mixture of
> sand, coal dust, and clay, among other things. It is
pounded into the
> mold over the model using a special technique and tools
that you need
> to be trained to use. The sprue and riser are added in the
other half
> of the flask and the models are pulled out and the mold
closed up.
> and the flask is poured with molten metal. After cooling
the casting
> is taken out of the sand.
>
> Then there is a lot of cutting and grinding and polishing
to get it
> into a finished item.
> This is not a do it yourself project. You need training,
and a lot of
> special equipment.
>
> Fred
> --
> From Fred Paget, Marin County, California, USA
> fredrick@well.com
>

Snail Scott on wed 5 may 04


At 02:17 PM 5/4/04 -0400, you wrote:
>I am interesting in making a sand-cast copy of one of my bas reliefs.


To cast in what material? Clay?

-Snail Scott
Reno, Nevada, USA, EArth