Rapline Processor Scratching Media

[pdan]

Shamefully, I'll admit it...I may go months without cleaning my Rapline 17 processor. We process 5 mil poly plate material. I have noticed, after cleaning with warm water & processor cleaner over the years, that scratches could be seen after cleaning. Depending on the press they went to, the lines were faint enough not to be a visible problem. After a thoughough cleaning last week, the scratches were too dominant to run the plates. I looked carefully and removed the steel guide plate(s) in the first rack, found built up sludge, cleaned it up, and ran plates with no scratches. The following morning the scratches were back, dominant. Recleaned the same guide plates, re-installed, ran good plates. Today, again, unusable scratched plates.
Am I cleaning the correct part?, what is recommended for this area of the machine? I'm considering something like Slip Agent 6 from Varn, no longer available locally, or a good silicone.
I do have a second Rap 17 that I'll swap the rack and see what results.
jpg attached shows the lines, about 4.5mm/.18in apart, running the transport direction.

 

[VladCanada]

That looks like one of guides sits OFF the setscrews and takes inproper place, making the gap between the media and the guide less than normal. Regular lines told me - plate material is in touch with the guide all time, that's ubnormal.
Another reason of lines - plastic bearings worn out and roller moved down, closer to the guide.
Anyway, keep going in swapping-up the racks to find a culprit.