After acquiring, I did a thorough clean-up the ink rollers on my SP-20. That was months ago, and they have remained somewhat gummy, tacky to the touch. At first I thought it was due to the humidity, but that’s no longer an issue. They were pretty crudded up & I gave them a good scrubbing using cotton rags and paint thinner. Is that the problem? Is there another solvent that’s better to use in future, and is there a solvent I can use now to retard the tackiness & keep them clean and dry?
Thanks!
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OK, this sounds like the problem I have right now, except mine are “just tacky” and definitely not oozing. And this did not begin to happen until printing silver metallic ink awhile back. Since then I’ve cleaned and cleaned, with mineral spirits, and lately with Crisco, and they are still tacky. Are these beginning to go? Should I replace the rollers? Next cleanup attempt will be with Easy Street, which I just ordered. Is that likely to help? Thanks for your answers.
The best available material is Nitrile rubber, a synthetic , commonly also known as Buna-N. It is stable and resistant to oils and acids. This material spec’d by NA graphics and all other suppliers.
Thanks, Eric. Any recos as far as replacement material? Is rubber the best?
It is time for new rollers. Nothing you do will improve the quality of inking with the failing rubber you have, but new rubber will make a huge difference, assuming the rollers are made for letterpress.
…a couple of more pics…
Here are a few photos. Looks like they are oozing where gravity pulls and tacky elsewhere. The “goo” is a little greenish-black; not sure if that’s the material or old ink. Fortunately they’ve been off the press for a while, so no extra mess there.
Are these shot or can they be salvaged? What’s the best replacement material?
Thanks as ever.
A photo would help. Are they just tacky or are they oozing. They could be old urethane roller, in which case, they will melt onto the ink drum and bed. This is a sticky mess. Get them off the press while you investigate further.