Proper roller maintenance is critical to keeping your alcohol dampener in good condition and operating at its optimum.
Metal rollers must be kept clean, smooth and free of oxidation, and soft rolls must stay soft and sensitized to remain hydrophobic and ink free.
Metal rollers can be cleaned with most good quality plates cleaners, then wiped clean with water and coated with a 50/50 solution of gum and water.
Rubber rollers require special care since they have open surface pores that can accumulate/collect contaminates from the printing process. Ink pigments, paper sizing, and traces of some alcohol substutites accumulate in the roller surface causing the roller to loose its’ hydrophobic affinity to where it carries less and less water and eventually picks up ink.
When this happens you must deglaze and recondition the soft rollers to re-develope and sensitize it’s surface to reject ink and attract water.
First you must remove all contaminates with a good cleaning. A product called ‘Mati-clean’ works well as the first step in removing roller contaminates. It cuts ink pigment and paper sizing well. A 50/50 mix of a good water misible roller wash also works well as the step #1 wash to remove surface contamination.
Once you have performed a complete step #1 wash, step #2 is to rinse and lightly scrubb the rollers with a liberal application of isopropl alcohol to remove any hint of a petroleum film/residue from the rolls.
Then step #3 is an application of a 50/50 mix of gum and water will coat the roller to where it will accept fountain solution without rejection.
When not using your press, always coat your ‘clean’ fountain rollers with an application of 50/50 gum and water to seal the surface until next use.
A quick test to tell if your rubber rollers are becoming contaminated is to wipe them briskly with a cotton pad saturated with isopropl alcohol. If you wipe off a purple stain its an indication that your rollers are absorbing blue paste toner and other dyes used in ink.
If you find that you are increasing your water setting, chances are your rollers need to be cleaned and re-conditioned.
Note: If this cleaning procedure does not bring your soft rollers back into a usable state, check durometer to determine if rubber has hardened beyond specifiactions.
In an emergency situation, you can hand scrub soft rolls with a fast dry deglazer to remove a deep glaze condition, but always follow up with alcohol and then 50/50 gum solution before use.
If durometer it too hard (beyond specs) replace all soft rolls as a set.