My memory is a little vague on this one. MC begins making swords and other metal work. Comes to the attention of beings from other realms both to make weapons and in conflict. Starts to gain power and becomes a force in his own right. Begins near current times. ISTR his work area is through a gate and outdoors in a wooded area. Again, I thought it was a Howard Faxon story but can't find it in his list.