Got ink stripping problems?

In many cases, the culprit is ink that won’t stick to the copper drums, which causes the printed page to be too light or have no ink at all in the affected area.

Press operators have tried to fix this by wrapping ruby lithographer tape over the affected area or using a copper coating solution to improve the drums’ ability to repel water.

While these tactics might work short-term, they aren’t a permanent solution.

If the copper is worn off and the underlying steel is apparent, the best solution is to replace the copper drum with a new or reconditioned one.

Buying reconditioned drum

To buy a reconditioned drum for a single-plate-around press, such as a Goss Community, will cost about $260. For a single-width two-plate-around press, figure about $390 while a refurbished Metroliner copper drum will set you back about $800. Contact your parts supplier for exact pricing.

Fig. 1 (above) shows water droplets on a copper drum that is in good condition. Notice the height of the water droplets. The droplets will not spread across the surface of the drum easily, which creates a drier surface, thus allowing the ink to adhere to the drum. Figure 2 (below), on the other hand, shows a drum that’s coated by film and other debris, which allows the water droplets to spread across the copper’s surface. Eventually, the water will form a continuous film, causing this area of the drum to lose its ability to carry ink.
Photos: Frank Bourlon

There is also the chance the copper drum may not need replacing. It may instead appear dull, which might fool you into thinking the steel is showing. Or, the drum might have a film coating, preventing it from repelling water as rapidly as it needs to (see Figure 1 and Figure 2, above).

If your drum does have film, remove it with a copper or brass polishing solution. It may take some elbow grease to dislodge the hardened deposits of ink, paper and chemicals, but it provides excellent results.

Before applying the cleaning solution, remove the ink rollers that contact the copper drum. This will allow better access to the affected area. Be sure to remove all of the polishing solution with water after you have finished the process.

If you have the time, remove the drum, install it in a lathe and use a scratchy pad to remove more of the deposit. Finish by smoothing the surface with steel wool. The drum will look and work as well as brand new.

You can also use the pad to clean the drum while it is on the press. To do this, remove the two ink rollers, then go to work, removing as much film as you can, rotating the press to a new position to expose more of the drum’s surface as needed.

Just as effective

This is just as effective as removing the drum, but the appearance of the drum will not be as smooth. You can employ the same approach to clean other types of ink drums as well since they will eventually all develop the same condition.