What do you do if the iron head is black and not touching the tin?
A head cleaning cotton to sell it, with one yuan a piece can also be used to the part of contusion and itching, blunted (Branded head life short
Polish the oxide layer and expose it. Then apply a little rosin to the tin
Iron head dark tin not see what head. If the general head grinding out a new copper plug, after the release of the temperature in the rosin can be fooled up tin after tin. In the temperature up after no tin in the air before not dew. If special grinding head can not use wet cloth on the sassafras OK
