It turned the copper color because you used too much. You want whatever you use to apply it to only be damp, not wet. And follow David's advice about the instructions, you do not want to overlap any strokes.

LMF Brown is quite fussy about application. I've always had better luck with Wahkon Bay Tru-Brown, which is nitric acid based, LMF brown is not (although I can't remember which acids it's mixed from off the top of my head).

Good luck

“I left long before daylight, alone but not lonely.”~Gordon Macquarrie