I'm using the setting Caswell Europe suggest (0.14A & 90F)
Anyway I tested three similar samples today - 3" lengths of steel tube that had a surface area of 5.65 sq in.
Used a second heater to get the temperature up - was 35 centigrade (95F), and the parts were warmer than that from the cleaning dip.
Plated them all for 20 minutes at the following settings:
0.56A, 0.68A, 0.79A
That covers 0.1 to 0.14A per sq in.
Results were all very similar, part plated but was covered in a grey layer that looks very similar to grey primer from a spray can (similar thickness too).
It took at least 5 minutes for the acid dip to remove this layer.
Part after plating:
http://users.pandora.be/peter.morley...s/Plating1.jpg
Close up of the grey finish:
http://users.pandora.be/peter.morley...s/Plating2.jpg
Part after 5 mins in acid bath - still some trace of the grey layer:
http://users.pandora.be/peter.morley...s/Plating3.jpg
Also tried one with brightener and no noticeable effect.
It still seems to me that there is something contaminating the surface finish, no one else mentions having to do so much work to reach the plating.