Odd ink issue

[Infinity]

We've been using Hostmann-Steinberg INKredible for most of our web duties (non-process). We've had some recent issues with it completely blinding to our plates. You can wipe the plates, and start again, and the image will look fine for 1000 or so, then it blinds again. You can stop the press and wipe your finger across the image area of the plate, and it will be clean. This first was noticed on PMS 430, but we run it nearly 100% of the time on one press.
Now, we've changed our chemistry several ways, and reset rollers, cheating to both fat and skinny stripes. The ink rep blames our fountain solution, and the chemical rep blames the ink. I do know that simply putting Flint or Wykoff in the unit will immediately run with no other changes. We'd prefer to stay with the H-S ink as they are local to us and we can get our ink in about and hour's notice.

Any ideas? I no longer run that press, but knowledge is power.

 

[CD102]

It seems to me that it has to be an ink problem if other inks run fine with the same chemistry that won't work for this other ink. Can the ink rep provide you with a fountain solution that will work with his ink that won't cost you more money or cause other problems such as disposal, etc.?

In my years in the industry, it always seems like a new ink will work great for a number of months, then as time goes on you start having troubles. I think the reason is they give you a great product at the outset to get your business. They are making little or no money at the start. Then as time goes on, they start cheapening the formula by changing vehicles or pigments so they can make money.

I'm not saying it's happening in your case, but it happened at least a half dozen times over my time as a printer. These ink companies have the same reasons to reduce costs that every other manufacturer has.

 

[D Ink Man]

What is the gray's coverage, take off? There is a lot of room for error with this tint blend. Color strength is the first thing I would look at. An ink film thicnkess gauge can help you. Ideallly a spot color runs best at .5 to .7 mil thickness.

 

[GazKL440]

Look at whats changed first... Im assuming you have been using the Hostmann for some time and its only recently that this problem has cropped up?? So what's changed recently? New plates? New Chemistry? Plate chemistry? Paper type?? Obviously something is amiss, and inks tend to be fairly stable batch to batch, we also use Hostmann Inkredible (impression series) and it gives us no headaches at all..

 

[Infinity]

Look at whats changed first... Im assuming you have been using the Hostmann for some time and its only recently that this problem has cropped up?? So what's changed recently? New plates? New Chemistry? Plate chemistry? Paper type?? Obviously something is amiss, and inks tend to be fairly stable batch to batch, we also use Hostmann Inkredible (impression series) and it gives us no headaches at all..

It's something we're still dealing with. Hostmann admitted that their bases changed about a year ago. We did also have to change fountain chemistry as the stuff we used was discontinued. Now we use Varn Majesta 400. We have no way of testing ink thickness, but the breakdown occurs more quickly with less coverage.

It just bugs the hell out of me when I can't fix something.

 

[GazKL440]

Yeah i had noticed some differences in their ink and queried the supplier over it, some inconsistency in the tack tin to tin, but it has still given us no real problems...

And yes, an issue that doesn't present with a solution can drive any printer nuts!!

Hope you sort it out... for what its worth we use 'Solar Fount' supplied by Ferag, and when we used Varn 'Fast Fount' when we installed our Komori, it gave me no end of dampening issues, such as steels inking up and metering rollers requiring a clean up 2/3 times per shift, not to mention excessive back cylinder build up that would drip onto sheets and stick them together...

 

[Infinity]

Well, I have "discovered" something. Now that I am the lead guy over a press, me and my partner experimented with some roller settings. I am pointing fingers at the ink company, the fountain solution, and our roller supplier. We have some new roller specs (since all our presses....and operators are alcohol-era guys), along with some new striping procedures being worked out. Since we've gone alcohol-free, we have had some issues. I think we can get it going now.
I do want to thank you all in this thread, plus everyone who has contributed the bits and pieces of information I culled from the offset forum.