All our Al-Ambiq® pot stills are soldered with copper, brass, 100% lead-free tin or silver. Brass, 100% lead-free tin and silver solder is perfectly safe and is commonly used for soldering copper for food use. The main elements in solder we need to avoid are cadmium and lead.
The first union of the pot (boiler) is made by overlapping the sheets of copper, melting the two extremities and then hammering this area on an anvil so that the copper may regain its molecular properties and strength. With high temperatures copper becomes very flexible and limp.
The other sections of the pot are soldered with brass soldering. Brass is an alloy made up of copper and zinc and is well known for it hardness and workability. Brass soldered joints are also hammered on an anvil to strengthen it. All areas of the still that will sustain high temperatures are soldered with brass soldering. The other joints of a still that are not exposed to such high temperatures, as in the pot (boiler) and where hammering is not possible - a 100% lead-free tin solder is used. Tin solder flows easily at a lower temperature and thus there is no need to hammer the copper parts as its molecular structure is not altered. Tin solder is used for the piping and to attach the thermometers. Tin is very good at adhering to copper and is not very soluble which is important as alcohol is a known solvent, and you may have hot alcohol vapours inside a still.
Cadmium free silver solder is mostly tin with a small amount of silver. It uses higher temperatures to get it to flow but it too has excellent adhering properties. Silver solder is used to solder the brass handles and other areas of specific stills. Whichever alloy has been employed in the soldering, our customers can be assured that these will not in any way alter the flavouring, colouring or final results of the distillate.