Here are my current ideas on the casting process and all needed tools. I have no idea if this process will work and if the tools are right but I am sure I will learn …
1. “Wax” for “Lost Wax Casting”
To create the actual shape of the mouth piece and nest area, I will use a wax based material to create the mold and cast the pieces using the “lost wax method”. One option would be to carve/file a wax block to the desired shape. But because I love high tech, I decided to use a 3D printer to print the models. I found a certain type of filament that can be used with most regular 3D printers. The wax material is supposed to “disappear” when I burn the ceramic mold around the “positive” shape to create the “negative” form.
The brand of the filament is called “PolyCast” and the maker is “Polymaker”. Here is the link: click here
I am using the software Fusion 360 (click here) to model all the parts in 3D. To print the model with my 3D printer I am using the free “UltiMaker Cura” software (click here).
Here is the 3D model file (only mouth piece and a long bore) of the flute: click here
2. Investment
The powder to create the mold is called “investment”. This powder is mixed with water to create a “thick paint” that is used to cover the “positive” wax model that I have created in the last step. After drying the covered wax model it is burned in an oven, the wax is burning away and what’s left after the burning process is the negative form / mold that can be used to pour in the liquid metal. Unfortunately the “paint” will contain a lot of air after mixing with water which should ideally be corrected in a small vacuum chamber to create a “paint” that is as smooth as possible. I decided NOT to invest in a vacuum chamber in the first step and see how far I can get regarding casting detail if I just live with it. I suppose I won’t be able to create very fine surface details (rings, coins, etc.) but the two pieces (mouth piece, nest) are not very detailed and I might get around the cost of the vacuum chamber.
I have chosen the following investment powder because it is available in Germany: click here
3. Burnout
After the investment material has dried around the wax model it needs to be burned. First to get rid of the wax inside and second to harden the investment (ceramic) mold.
I found a decent priced oven that should be able to do the job It is rather small but the everything I want to make incl. some other projects like rings etc. should fit. The important part is that it can be programmed to heat in certain temperature cycles which is what the investment supplier specifies for the burnout process.
Here is the link to the oven: click here
I have ordered it a few days ago and it should arrive today. I am very excited to try it out!
4. Melting the metal/silver
In order to melt the silver I need a temperature of around 1100 degrees celsius. I guess this should work with the burnout oven but there a special small melting ovens that make it easier and that are made for this task. I chose a cheap one and hope it will do the job.
Here is the link to the melting equipment: click here
5. Casting
If everything works out the way I imagine it, the last step will be to pour the liquid silver into the mold, cool it off and that’s it! In theory it would be good to use vacuum once again to make sure there are no air pockets but like I said I will try to avoid this additional equipment. I guess if the model / mold is designed in a smart way, the level of detail will be ok for my purpose. I might be totally wrong … We will see!
6. Soldering
All pieces need to be soldered together. This step is crucial for functionality but also for the looks because of the seams that I want to be “invisible”. I suppose this step needs the most practice. I am using a gas based jeweler torch for this step. Its a very cool little device that I am also using for my jewelry work.
Here is the link to the torch: click here
Beside the torch I need “silver solder”, “soldering flux” and some “sodium bisulfate” to get rid of the oxidation after casting.
All the missing stuff is now ordered (08/11/2023) and should arrive during the next days. I will keep you updated …
