Gold Stripper

My question concerns stripping gold from sulfamate nickel in a reel-to-reel application.

When attempting to strip 1-5 microinches of bleedout off of our parts it would appear that the gold strippers we use are stripping the high thickness areas of the part at a much faster rate than the bleedout. Usually we compensate for this by increasing the gold thickness in the critical areas. By doing this, it gives enough of a buffer so that we can effectively strip off all of the bleedout before the critical areas go out of spec. The major problem we have encountered is when we are required to run a low thickness deposit (10-15 microinches). We have not been able to strip the bleedout without creating bare spots in the critical areas. The difference in thickness of the two areas should be adequate enough to allow us to strip off all of the bleedout (1-5 microinches) without stripping off 15 microinches in the critical areas.

Can anyone explain to me what is going on? Is the surface on the nickel interfering with the stripper?

We have had this problem for several months now and any suggestions would be greatly appreciated.