has any one ever used pickle brine to soak there salmon befor smoking
No, I haven't used it for salmon. It may alter the taste. You can use as little as 1.5 ounces of cure #1 per gallon of water or liquid. That amount may not alter the taste of your salmon, but I can't be sure. You can add as much as 4.2 ounces of cure #1 per gallon of liquid. The more cure you add, the deeper the red color will be (if salmon has enough myoglobin), and the more of the "ham" like flavor will develop. You can add the cure to your favorite brine, just reduce the amount of salt by the amount of cure you add, and use your same brining times.