Taking a casting of the interior of an antique natural horn mouthpiece
To copy the mouthpiece, you need to make a mandrel. To make the mandrel, you need some measurements. It's easiest to take the measurements from a casting of the interior of the mouthpiece.
I'm told the original way to do this is using wax and cornflour as a release agent. I've used 'Polymorph' - a low-temperature thermoplastic something similar to glue-gun glue, but a bit more rigid and not as sticky. No release agent required.
Dip both mouthpiece and plastic into hot water and wait for the plastic to soften, then force the plastic up the interior of the mouthpiece using your thumb. Leave in the freezer for a few minutes, then remove the casting. I found I had to cut the plastic off of the top before I could pull it out.
Taking a casting of the interior of an antique natural horn mouthpiece
To copy the mouthpiece, you need to make a mandrel. To make the mandrel, you need some measurements. It's easiest to take the measurements from a casting of the interior of the mouthpiece.
I'm told the original way to do this is using wax and cornflour as a release agent. I've used 'Polymorph' - a low-temperature thermoplastic something similar to glue-gun glue, but a bit more rigid and not as sticky. No release agent required.
Dip both mouthpiece and plastic into hot water and wait for the plastic to soften, then force the plastic up the interior of the mouthpiece using your thumb. Leave in the freezer for a few minutes, then remove the casting. I found I had to cut the plastic off of the top before I could pull it out.