Ever try pipe soldering flux?? If you brush it in while the copper is hot let say 600-800F then wipe it off copper comes out brilliant pink copper. Great channel always look forward to you videos.
I stoped use of borax some time ago. IT stick to crucible and its mess. I stir very well metal when its in pouring temperature and that make all oxidation emerge to the surface, where i skim It with spoon. Its good to do that twice before pouring. For me thats the best option but i cast only small objects in brass.
For me its not what's on the surface but what is the porosity level inside the casting. I need to rough cast copper for machining it into parts later. I don't want any bubbles in the casting. It would be great if you would cut some ingots in half so we could really see what's going on inside. Thanks
@@calvinsalim2375 it helps keep the oxidization under control... the borax lowers the melting temp of the glass, and forms a layer on top preventing oxidization
@@jacobpeters5458 as soon as the metal starts to melt, add a teaspoon of borax, and a handfull of glass shards... the borax will lower the melting temp of the glass and make a molten glass cap to keep the oxy away from the metal... no prep needed
