Several things take place to cause ink piling on crestlines.
- Roller pressures make sure roller contact stripes are parallel and set as follows. If the specs say 2-4 mm then set stripes from oscillator to form at 4 and from form to plate at 3-3.5. Never reverse these two settings.
- When you transfer the image from the plate to the blanket, a percentage of the ink is left on the plate, on a good day 4% on a not so good day as much as 11%.
The first thing the plate image touches after the transfer is the crestline ink/water form. Because you run both ink and water on the entire water system the surface tension of the ink on the ink/water form is higher than the residual ink on the plate and the ink/water form picks the residual ink off the plate and guess what! It ends up in the water system eventually causing piling on the crestline.
To add insult to injury, the crestline has no chrome roller in the system and ink is allowed to feed all the way back to the pan roller making it impossible to carry thin & even films of water.
- Most silver plate fountain solutions have everything in the kitchen sink in them, alcohol, surfactants, some times driers. These types of fountain solutions run very wet, thick films of moisture creating a constant battle with emulsification.
- Run a fountain commercial style fountain solution designed for poly and metal plates. We happen to make one.
The fountain solutions should be of the two step variety having a base and an alcohol sub that can be varied to adjust the surface tension for the desired effect on that press.
- Be certain that you do not have a calcium carbonate/size poisoning situation. See our article “The alkalinity problem”.
Mix part 1 of the fountain solution to the recommended ratio and run the press. Do not adjust the part one ratio. Instead observe the press, if it is piling or you are building up ink on the lead edge of the plate , add the alcohol sub, (part 2), in increments of 1/2 ox per finished gallon of fountain solution. Continue to add and observe until the crestline runs without piling.
Record the ratio of fountain solution and alcohol sub and always mix to this ratio for this press. If the ratio needs to be changed in the future one of three things is wrong:
- I screwed up making the fountain solution.
- there is a calcium carbonate issue.
- there is a mechanical problem.
If you need further info please feel free to contact me. We manufacturer both our inks and our chemistries so we can insure compatibility throughout the system.
Etv concepts inc.
Toll free 1-888-449-4317
Dave Baron passed away2011 after a long bout with cancer.