Striation lines while plating sheet metal

[mnt mike]

I have been silver plating copper sheets and getting a strange effect. I polish the copper to a mirror finish and clean it in an ultrasonic tank and proseed to plate it in a tank, the results produces a nice plate but afeter it is polished I quite often see striation lines inthe center of the plate. The line are not produced in the polishing prosses but apear to be in the metal. The copper is new sheet metal 16oz copper, in it's new state you can see fine striation lines ( are these caused by the rollers ) but when polished no sign remains until plated. The line usally show in the center of the plate with the outer area being well plated. I do not know if the copper is cold rolled or hot rolled would this make a difference ? Dose the size of anode have any effect on how even or thick the plating is, I currently have 2 pure silver coins about the size of silver dollars suspended in my two gallon tank while the 4x5 in plate hangs about 2 in away with voltage set between 1.8 and 2v.
Thanks, Mike

[mcaswell]

Very odd?

Do the lines remain when the final silver plate is polished?

[mnt mike]

Yes they do, I have been plating very lightly and the heavier areas around the edges are fine but the center shows the lines. When I turn the voltage down and plate longer I get a nice heavy plate without the lines but then I have anothe effect that looks like small bubble of oil floating on water yet the plate is pefectly smooth.

[mcaswell]

Post a problem report in PRS and we'll try to help with this.

http://www.caswellplating.com/support.htm

[jhillyer2]

Field Effect

Yes they do, I have been plating very lightly and the heavier areas around the edges are fine but the center shows the lines. When I turn the voltage down and plate longer I get a nice heavy plate without the lines but then I have anothe effect that looks like small bubble of oil floating on water yet the plate is pefectly smooth.

In this world, everything affects everything. In plating one or more objects, each can affect the other in liquid flow, density, electromagnetic field effects, also with the container. A subtle ripple in supply current can augment natural reflection and inductance effects, especially on sharp edges and flat panels. This conjecture does not offer a solution, however.