Last Updated 12th April, 2021
Casting with Delft Clay is a easy and pleasant experience and does not require many tools or prep work. Users of Delft Clay can expect a high quality result even with little knowledge at a beginners level. Lets not waste anytime and get straight into it.
What you need:
- 1 Aluminum casting rings set or flask.
- Casting metal in this case pewter
- Heat source that can melt your chosen metal (blowtorch).
- Straight Edge (metal ruler)
- Talcum powder
- Tooth pick and small knife or similar
- Delft Clay.
Something to cast:
- In this case a Twig.
Place the bottom ring of your casting rings set on a flat surface, the bottom ring is the one with the rim on the inside (it fits inside the top ring).
Fill the bottom ring to the top with Delft Clay making sure the compress the clay as you go.
Use a straightedge to "cut of" the excess, making the clay totally flush with the rim.
Using the straightedge again remove the clay off the outer rim so the rings can be joined together flushly. Then clean up all the unused clay and put to the side.
Add talcum powder on top of the delft clay, gently use a light bristle brush or you finger to smooth the talcum powder to cover the whole area of the clay, this is to stop the object we wish the cast and the clay we are going to put over it from sticking and ruining the cast.
Place the object (twig) you wish to cast in the dead center and evenly apply pressure down till half of the object is submerged into the clay. Once again dust with talcum powder (including the object) and blow the excess off.
Place the second half (the top) of the aluminum casting rings on top of the bottom half. Making sure the what I call "center line" is matched up and both rings are evenly connected (which they should be if you followed step four correctly).
Just like step two we need to fill the empty top ring with Delft Clay too. Remember to compact the clay as you fill it up.
Carefully pull the two rings apart and remove the object (twig). Best way to pull apart is to hold a ring in each hand and pull away from each other, under no circumstances twist the rings to loosen them in anyway as you will disturb the clay and ruin your "molds" negative impression(s).
From now on take your time, go slow and be careful not to wreck you "mold". On the top ring, the one with the outer rim, take a toothpick or similar and make a hole on the clay near the end of the objects imprint like the figure below shows.
Push the toothpick through and pull out the other side (of the top ring).
Using the knife make the hole made by the toothpick into a funnel shape about halve way down deep this is what we will be pouring the metal down.
Using the toothpick once more make the hole wide by circling it around the hole, being careful not to damage the negative impression.
Make two holes with the toothpick near the "branches" of the twig and then make tiny paths with the toothpick these will act as air holes so the air has some where to escape when pouring.
Double check all the holes are actually holes and haven't "caved in" and rectify them if they have with the use of the toothpick.
Carefully align the rings and place them back together (bottom ring with the inner rim on the bottom).
Melt how much metal you think you need into a crucible with a blowtorch and then add a bit more. It always pays to have more than less as having too little will ruin you cast. Always wear necessary safety gear: gloves, goggles etc.
Have your crucible and blowtorch as near as you can to the rings. Once the metal have melted and the crucible is warmed to the point it's not sucking the heat out of the metal and cooling it straight after you remove the flame. Slowly lift the crucible to the pour hole while moving the blowtorch with it, to keep the metal in its molten state and in one quick but very controlled motion pour the metal into the pour hole and remove the blowtorch.
Once you have poured the metal, wait for it to cool down before touching/moving it. A small pewter object like this won't take very long to cool down maybe 10mins tops.
Once cooled you can pull apart the ring and see what you have got.
Finished (well almost)
20 steps! and we are still not really finished! you will need to finish off the casting by cutting the spur off (the funnel which we used to pour the metal) and snipping of the little air hole paths, you may also need to sand, file and polish depending on your cast quality and wanted result.
Thanks for for sticking it out and reading the whole tutorial, all the best with your future casting :)