Aluminium soldering aid thermal block.
Used to protect heat sensitive stones when soldering ring shanks by immersing in a shallow water bath.
Irrigation channels keep the reservoir being used from drying out too fast by allowing water to flow in and replace the evaporated liquid.
The depth of the hole can be adjusted by adding sand to achieve the desired level.
****Please check the suitability of a stone to be submerged in water for short periods of time****