was: Copper coating on silver in tumbler
Making sure the pickle that gets inside any hollow form is properly
neutralised can be tedious and tricky - especially those forms with
only one tiny hole to allow gases to escape when soldering. I use an
old medical syringe and inject the baking powder solution - works
like a charm. Then I inject clean water to rinse out.
The difficulty lies in getting hold of syringes without being taken
for a drug addict