RA-4 flaw with blotches of differing density

[bottlegardener]

Hi all,
I posted this in my RCP 40 Vario thread but it got a bit buried and it seems maybe more universal...
Just wondering if anyone knows what might be causing the issue highlighted in the white boxes on the attached test scans (please ignore the dust, the scanner is rough shape)?
It is happening exclusively on the side of the paper that enters the machine first. I've read through several RA4 troubleshooting guides (including Kodak and Fuji documentation) and nothing mentioned really seemed like this problem to me.
My only two wild guesses are 1) the stop bath, being unheated and significantly colder, is causing some sort of artifact or 2) in the brief moment where the paper is trying to grab the stop bath rollers, little droplets of developer are continuing to work.
It'd be great if someone could point me to a more informed theory.

 

[Mick Fagan]

Bit of a wild guess here as well.

Could it be droplets of condensation in the in-feed tray forming and being picked up by the first part of paper that is slid over and into the first feed in rollers?

I run a Durst Printo and prior to that a Durst RCP20. I haven't done colour printing in a few years, but I still run B&W paper through my Durst Printo. I saw that kind of issue on both machines, mainly in summer time when I have air conditioning on in the darkroom.

The machine is running at a high temperature and the darkroom is around 23ºC The in-feed section of my Printo is not heated and with the warmth coming from the first bath, condensation occurs in the in-feed tray as it is sort of in the cool air flow from the air conditioner. Last week when doing B&W I ran the bath at 34ºC - 35ºC and with the temperature differential of the room I get plenty of small droplets of condensation on the in-feed tray as the air conditioner is on due to summer heat. I regularly wipe the in-feed tray, sometimes I cannot see the droplets of water, but using a fine closely woven linen tea towel, I can feel them when wiping.

Mick.

 

[bottlegardener]

Thanks Mick, that's really interesting! It was probably only 16-18ºC or so in the room, so condensation was likely.
I also just saw that tortured Google translation of the German RCP 20 manual warns something similar:

"Important!
By removing the cover of the paper inserter wah-
During breaks, the machine is running
Prevents condensation. It is recommended, too
the feed rollers on condensation to OberprOfen
(see 4.1.0., important!).
Work steps outside the Maschlne:
After the finished-wound image to the device outlet
it can be immediately stabilized and dried
become"​

 

[Photo Engineer]

Do you prewet? This is usually essential. Good agitation is a must.

Prewet, Dev, stop, rinse, blix, wash is what I use.

PE

 

[btaylor]

Interesting. I have noticed considerable condensation inside my Durst Printo at times especially in the feed chamber but I never had a problem. I do wipe it down periodically just to keep things dry. I am curious, why isn't your stop bath at the same temp as the developer? On both my Printo (2 bath) and Beseler (4 bath) machines all the baths are heated and circulated. I also don't use stop bath, the print is squeegeed by the exit rollers from the developer and then into the heated blix. Maybe try that.