Dear Riccardo et al.
I think, I’ll go ‘Orchid’ on this subject, as I have already got a
few mails about it and it obviously is of major interest to a larger
forum. So here is the answers to your questions:
Sand casting is a method that has a lot of interest for me. I have
experimented with it a bit and find the directness and immediacy of
the method quite rewarding.
A couple things that I would appreciate hearing about from you aRe:
- What do you use for frames? Here, there is usually just one small
frame that you can get commercially. I am thinking to make my own set
from welded angle iron, but there may be better ways of doing this.
I normally use either cylindrical frames made of steel or some cast
iron frames in the shape of a bottle, the latter ones being of East
Indian origin (so my supplier tells me). I have also tried some
homemade wooden frames, but not with the same success.
- What kind of sand are you using? I can get all types of sand from
foundries in the area, but you have to buy it in 100 pound sacks. Is
there a particular type of sand that you use and like? What about the
I use a type of ‘sand’ that I buy from one of my tool and metals
supplier. It has a dark red colour and an oily feel. I heard that it
consists of finely crushed bricks mixed with oil, and I have tried to
put it under a microscope. It looks exactly like some crushed brick,
which I tried to make just as a test.
- Do you have any written guidelines for the way you work?
Nope, but Martin Niemeyer of The Netherlands just sent me a thorough
description, which I - and I hope, I have your permission, Martin, -
will copy heRe:
"Description of the Delft clay casting method.
- Place the ring with the inner connecting rim on top, on a flat
surface. 2) Fill this ring with the Deft clay, and ram this stuff in
with a hammer. 3) Wipe the surplus of with a ruler. 4) Put the model
half way down in the clay. 5) Cover the filled ring with talcum
powder, and brush it with a soft brush, all over. 6) Place the second
ring, with the marks toward each other. 7) Fill this second ring with
clay, ram it , and remove the surplus. 8) Remind the marks and take
the two rings apart. 9) Remove gently the model. 10) Push with a pin
(round 4 -5 mm) from the model print, to the outside of the casting
ring. Also make 2 -5 ventilation holes with a 1.5 mm pin. 11) Make
with a pocket knives a casting cone around the 4 mm hole. 12) The
casting cone should directly connect to the model print, and the
ventilation holes should connect to the, most far away sides of the
model. 13) Place the two ring together, reminding the marks. You are
now ready to cast. 14) The melt should be heated during casting. Take
enough material so that there will be enough force to push the metal
in the mold. Also the meld should be as hot as possible so that there
will be no blocking of frozen metal. 15) The casting clay will burn 1
mm in, remove this and the rest can be reused.
… and may all the gods of good casting be with you.
Kind regards from Denmark, where the autumn is colouring the leaves.