Hi All,
I have inherited a GTO 2 colour press, (the previous minder has just retired), and I am absolutely plagued with hickies. The guy who has retired has put up with it for years and tried everything to stop them, but he had no luck. The other single colour GTO that he ran had the same problem, is this something that is peculiar to GTO's? I have no experience of GTOs, but I am very surprised that a machine of this calibre should suffer from this problem.
I've never had this problem with any other press that I've run...........Solnas, Rolands etc.
Has anybody got any ideas, as it is driving me up the pole.
Thanks in advance.

Forgot to add that the machine has "bareback dampers"

Hi,

Have you taken the rollers out to inspect / clean them.
It could be a roller breaking up.
Has the vibrator damper cover been changed recently.
It is unusual to have hickies constantly.
Do you trim the paper before use, if you do is the guillotine blade ok.

Regards.

Thanks very much for your reply, mrheidelberg.
I've inspected the inkers and they seem to be OK. The paper is trimmed and the damper covers are fairly new. Am I correct in saying that the newer the damper covers, the more trouble I would have? The thing is, it doesn't seem to matter whether the covers are old or new, the problem is still there. The hickies do not seem to be fibres, but round "specks"....... It's a mystery!!
As i said, the single colour GTO suffered from the same problem.
I must admit that I am at my wit's end over this.
Any other ideas?

Hi,

Ok the damper cover shouldn't be causing an issue then.
If all the rollers are ok and i presume you have inspected even the middle inkers and the damp trough is clean ( and re-circulation unit if you have one ) then another common aspect could be the ink.
Does the problem appear on all jobs using different colours of ink.

Regards

Hi mrheidelberg,
The problem does appear with all ink colours. We use various brands of ink, but none of them give any better result.
I've been thinking along the lines of a new roller wash, anything you would recommend?

Does the weight of stock hae any affect on the problem?
Cover stock gets more hickeys than text? If so then maybe your rails under your water unit are not set and the sheets
are "slapping" on something under or up there knocking
crap down causing hickeys? Don't know GTO's, but had the same problem on 6C/72S. Good Luck to you.

Thanks bdk,
I'll check it out and will let you know if there is any improvement.