Riso suddenly printing very light

[gillje]

Ok, now I am having this problem on another drum (thats 3 now) for a different machine. It's a blue drum for a gr3770, all of the drums are being kept in their cases when not in use, and I was using this blue drum pretty regularly and was using it immediately prior to this happening... went through a several hundred prints just fine until it's started to gradually lighten...

The problem is that the drum is not drawing ink out of the tube, I ran the ink motor test and I could see the roller spinning inside, that would be a sign the inking motor is working right? If not how do I confirm that the motor is still working?

From what I've read could it be that screen in the ink pump is clogged or there is an air bubble interrupting the flow of ink somewhere? How do I resolve either issue? I was right in the middle of a job when this happened any input would be appreciated!

[bigste]

Could be a blockage in the motor or an air lock. Only solution will be to strip it down. I'd forget the idea that the motor is not working as it is on several drums. Have done the same problem a few times and advise to get some rubber gloves, you will need them.

[ddude]

Pretty strange that this is happening to any drum that you install-I know from experience that the screens will clog if they sit idle for any length of time, and it seems that citrus cleaner does the best job of cleaning the screens- remember that the wetter your rag, the better, and you do not need to scrub, just dab the solvent onto the drum screen.


Also, when you need to clean up ink off of the machine, or workshop table, or even off of your hands, use Windex- this works the best!

I bet Windex on a drum screen would do wonders as well- this new soy-based ink has some negative effects on our equipment, we need to adapt, because they ain't going back!!!

[gillje]

Got them working again! Just needed a pretty good cleaning and I had to clear out the tube that draws ink... worked like a charm. thanks again!

[ddude]

I would blame the new 'green' soy-based ink- this stuff will coagulate and goo-up the screens, which is something that would not happen with the oil based inks. We have seen more screen problems lately because of this change over to soy ink.