Poly Plates
Poly Plates
It is your wash-up. As of Jan 1st 2009, no more step 1 and step 2 are allowed in california, I do not know if you are in california or not. Enviromental requlations have put in alot of changes in the printing industry. We had the exact same problem as you described. We changed our ink rollers, metering rollers, foam rollers you name it , we changed and NO fix. We then changed to prisco powerKlen wash-up. You need to clean the ink rollers through out with prisco powerKlen, then use hot water and vinigar to finish it off. Make sure the rollers do not have any oily residuue on them and they are velvety. Check your "PH" fountain solution mix and make sure you are within 4.8 and 5.3. If you are below 4.8, the fountain solution mix will attack your paltes and you will get tonning, if it is above 5.3 it is not enough ph in your system, and you get scumming. You can buy HANNA PH meter from ebay.
Believe me I had the exact same situation like you. Alot of sleep less nights and we finally got it. Good luck, email me if you have any questions.