Water roller swollen at ends?

[lantz_xvx]

Hey everyone,

I'm having horrible tinting issues and it's giving me such a headache! I run an Itek 3985 with Crestlines. I use Universal Pink fountain solution and have taken to using a fountain additive called "Stopz-It" which is kind of a dumb name but does wonders to eliminate toning. The press is not in a temperature-controlled space so I've found that this helps to run less water and come out okay. The past couple of jobs I ran were small envelopes, and previously before that (in the Spring) I ran a 150 page book. I'm printing a booklet right now and BOTH heads have the same problem. At first I thought that the Crestline just wasn't inked up enough and if I dump ink into it, the issue goes away, but then it's way over-inked. I've been wrestling with it for days and some things I've noticed are:

- The ends of the Crestline pan roller have droplets of water on them, like the roller is not properly inked.
- When I look at the water form to plate stripe (picture attached), the stripe is thin in the middle and larger on the edges, instead of one even stripe all the way across

Anyone have any ideas? It's been a couple of years since we got new rollers and I know that Crestlines can be finicky, but honestly the press doesn't get used enough to warrant a roller change every year. Our work is mostly digital and letterpress, and the offset machine gets used really just for special projects. I'm way behind on one right now so any help is appreciated.

Thanks!

- Lantz

 

[Cornishpastythighs]

Start with the basics, Do you have a Durometer guage? so you can check the hardness of your rollers. your press manual should tell you what durometer is correct for your press. Even though you dont use the press much and it sits for long periods the rollers could be getting hard and using that chemical in your fountain solution may be having an adverse effect. Are you using some kind of roller lube on the rollers when the press is sitting for long periods.

 

[lantz_xvx]

No, we don't have a durometer gauge. No roller lube of any kind. I realized though that it's been about 4 years since I replaced the rollers, so I'm going to put some new Crestlines in there and post an update when I see what it does.

 

[lantz_xvx]

Yep, I've gone back through all of those. It's generally been roller pressures but I think this time the rollers are just shot. I've never seen stripes that look like this, at least not in a really long time. I'll let you know what happens. Thanks guys.

 

[Alois Senefelder]

lantz,



You have murdered the rollers by neglect - so what did you expect !

-- you have a poor understanding of printing by Lithography. PS Replace the Rollers and take better care of them.


Regards, Alois

 

[keith1]

- When I look at the water form to plate stripe (picture attached), the stripe is thin in the middle and larger on the edges, instead of one even stripe all the way across

There's a big difference in the amount of ink across your roller. Could be because it's swollen, as you mention. There's a lot more ink where the strip is thicker.
If swollen, the only cure is to replace. Avoid using strong chemicals to clean the rollers. Or at least use any strong chemical as infrequently as possible. It contributes a lot to swelling.

 

[lantz_xvx]

Thanks, Keith. Yeah, it does seem like the ink is heavier on that side. It might be because in dabbing a light coverage of ink for testing purposes, I just went a little heavier on that side. But the stripe looks the same with even inking. For cleanup, I use a vegetable-based wash called Brigl. It's great stuff that just needs to be followed up with warm water to get rid of any residue. In any case, I realized that the Crestline rollers haven't been changed in four years, so I ordered those yesterday and will install them when they arrive tomorrow. I'll be sure to post an update once all that is done. I appreciate your response.

- Lantz

 

[lantz_xvx]

Yeah, that's pretty consistent with my experience, alibryan. I feel like toning has always been an issue with the press, especially since the space we're in is not climate controlled. It's why I started using that additive in the fountain solution—it's barely half an ounce in a 32oz bottle but it really does help. I actually don't ever put ink on the Crestlines to ink up and rather just let it pick up ink naturally from the plate. You can always add ink later via the fountain but if you start off with too much, it's hard to get it out of there. How did you ink up those Crestlines? The manual says to put a light dab of ink on the "oscillator only" but I don't know if that's a typo or what, because the Crestline oscillator is not really accessible, certainly not to put ink on.

 

[blkraven66]

I know that I have had the least trouble running Kompac water systems . I know they are around $3000 a unit for Hamada presses. But , if you want the " set it and forget it " press......I'd get them . They can also handle the long time in between runs . Just my experience.

 

[lantz_xvx]

Thanks for the tip, blkraven. I have a printer friend who has a Ryobi 3302 (an actual Ryobi) with Kompacs and he certainly does have better luck running them but he's also had to deal with leaky seals and things like that. So it's not a total set-it-and-forget-it type of deal, as far as I could tell from just being at the shop with him. He pulls great work off of it, though. Still, the troubles with this press almost has me wanting to get a GTO with molletons.

 

[Alois Senefelder]

Hello lantz_xvx



Yes, a Heidelberg GTO, BUT why would you want to use Molleton Dampening Rollers ?



Regards, Alois

 

[Tomtech]

As a tech that has installed and repaired many Crestlines and Kompacs, I have found that Kompacs do seem to run consistently with less trouble but Changing the rollers on your Chrestlines does seem more practical economically. Take good care of your rollers. Good rollers that are adjusted properly to specifications will make your pressmen very happy. I suggest that they use a little slack time every month or two and check the roller pressure adjustments as well as looking at the condition of the rollers. Note how the new rollers look; note the roller surface and the velvet feel; this is how the rollers should look when clean and deglazed. Compare them to the old ones. This can be done at the same time you oil and lube it.
As rubber rollers age they often seem to swell on the ends and we tend to blame the absorption of solvent and wearing down of the rubber. the truth is that the rubber compacts as they are used. This is why the manufactures recommend putting the press in night-latch when not in use. The pressure spots will recover as you use the press, but using the night-latch when idle will stretch the life of rollers. Generally you should get one to three years out of a set of rollers depending how much they are used and the care they receive.
You have an excellent press, treat it well and it will treat you well as well.

 

[turbotom1052]

ink form rollers set too tight to the vibrator rollers will swell on the ends like your pic shows. The side to side action of the ink vibrator against the ends of the form rollers will over time begin to separate the rubber from the metal core.

 

[Alois Senefelder]

Hello fellow Lithographers,


turbotom, is correct.


Regards, Alois

 

[lantz_xvx]

Hey Tomtech, I am the press operator. And also the co-owner. We're a three person operation and most of our money comes from digital and letterpress printing, so the offset press really only gets used for special projects. You're right though, using the night latch is definitely the smart thing to do. I go through the pressures every time I use it just to make sure they're good, but a big issue is that we are not in a temperature controlled space, so they vary more than they otherwise should.

Turbotom, the uneven stripe was really only with the water form roller. The ink form stripes all looked good. The form-to-oscillator is only ever about 3mm, if I'm remembering correctly. (But not at the shop now so the settings I have written down are not in front of me.)

The update I have now is that I swapped out all the soft Crestline rollers on both heads as of Friday. I then set all the pressures—the water form pressure looks amazing now. So I'll do a full inking of the press on Monday and try to print, and see what I've got.

- Lantz

 

[lantz_xvx]

Ok, here's an update. I'm still having an issue with the Crestline rollers not getting sufficiently inked and that's leading to the same problem I was having before. The roller pressures are all set to spec and the stripes are fortunately nice and even now, after changing the rollers. It's Van Son ink, which I don't typically use but which I also have not had problems with. What am I missing?

- Lantz

 

[banjoman]

I ran a Crestline for 20 years, its been 10 years since we bought a digital Presstek BUT I remember changing rollers about every 2 years and you have to be diligent about deglazing and rinsing with water at the end of your wash ups. As far as not getting enough ink on the water rollers, are you bridging the water rollers when you ink up? Another thing, on the Crestline dampeners I used the fountain solution they recommended, it was made by Accel and if I remember right it was a 2 part solution, not saying it made a difference but I had very little issues. You sure your form to oscillator pressures are good? Make sure you didn't miss a transfer adjustment somewhere that's not getting ink to the oscillator?



banjoman