I read with interest Ray Nichols’ prior post regarding the resurfacing of his SP-15’s ink drum. The drum on my own SP-15 is also scratched, presumably from the previous owner’s use of the automatic washup system (the blade was missing when I bought the press, and I haven’t replaced it). The scratches on the drum are not terribly deep, but can be felt when running a hand lightly across. I’ve always felt that my press requires more ink than it should to achieve decent coverage. I’ve never used another SP-15 other than this one, but both the No. 4’s I used in the past did not need nearly as much ink as my press seems to. Additionally, the rear form roller, which comes in contact with the drum, never seems to have as much ink on it as the front form roller, until about halfway through a day’s printing, when by then there is quite alot of ink on the press.
My question is– does a scratched drum contribute to inking problems? I would be very interested to know if Ray and any others who have done resurfacing have noticed consistently improved results.
My two cents worth. I would be wary of removing metal from the cylinder drum with files or sandpaper. You do not want to remove surface material. Contact to the inking rollers could be compromised.
However, if metal is above the surface of the scratched drum that can be removed by very carefully placing a heavy duty ink knife tightly held against the bed of the press with the edge touching the cylinder (with the edge parallel) and moving it along the cylinder while the press is running. You will here a slight scrapping sound and some nicking sounds. When the nicking sounds are gone, you are good to go. Do this carefully so you don’t make matters worse. If you don’t have a steady hand, don’t do it.
Better yet, since this condition is a sign of mechanical neglect by previous owner/s, there are likely other problems to be found. If looking to buy a press, this as well as bearer rails disintegration or scarring, are pretty good clues as to its condition.
Gerald
http://BielerPress.blogspot.com
Ray,
Thanks for the suggestion. I’ll try that experiment, though unfortunately can’t get to it until next week. Since you did the drum resurfacing, is your press still inking without any problems?
Just for the record, I don’t think a file and emory paper is a good idea if you do much at all. There is no way you can keep things even.
I did try a file (very fine), very carefully to at least remove burrs on mine before I had it professionally done.
The place we did it was called J&A Grinding. So maybe try to look up ‘grinding’ in your are in your phone book or on the internet.
Indeed ours was DEEPLY scratched.
Something you might try with the press clean.
Roll the cylinder to the end of the press and ONLY ink the ink drum with white ink (so you can see the inking on the black rollers a little later in the experiment). Apply the ink with a brayer, making sure it is as even as you can get it and thinly inked. Maybe use about 1/3 as much ink as you might normally use to ink the press (you are only inking the one roller and not the 5 rollers as if you were starting a job).
Then raise the rollers so they won’t be touching the ink drum and return the cylinder to its starting point.
Then SLOWLY lower the rollers onto the ink drum. You want them to JUST TOUCH so you can see what happens. Keep lowering it until you are all the way down (should take you 60 seconds so you can see how the ink transfers as it lowers).
You should then have some sense if things are working or not. Just for the record, you are only adding ink to the ONE roller from the ink drum.
ONLY ONE ROLLER should be getting ink. If it inks in an uneven way you should be able to see it and make a judgement as to if you need to take it to someone with the right machinery.
Yvon,
Thank you for your comments. Since you say that your resurfacing efforts did improve performance, I’m inclined to try some sanding such as you did. I’m curious if you removed the drum when you did the sanding, or did you leave it in place?
I too am pretty mystified by the rear form roller’s lack of inking, but I don’t think it is due to the roller’s condition, as both rollers were new from NA Graphics, and the problem was evident from the first inking. So, it is most likely a mechanical problem, and I’ve been wondering if there might be some connection to the scratched drum.
Sylvia, I also ended up with an SP-15 with a scratched up drum, thankfully not excessively. I used a very fine file to take the worse burrs off the surface and finished off with a fresh piece of fine emery cloth sandpaper (600 grit as I recall) wrapped around one of those all-purpose sponge sanding blocks (to adhere to the round surface of the drum).
My drum certainly doesn’t look as good as Ray’s after resurfacing (https://vandercookpress.info/vanderblog/2012/02/resurfacing-our-sp-15-ink-drum-roller/) but I feel it has improved performance.
Can’t understand how the rear form roller would get less ink on it, perhaps the spring holding the drum is so taut that there is too much contact? Or that roller has become more glazed over time and is not as receptive to ink. A good wash down with something stronger than what you might normally use might be in order.
Then again, it could be mechanical, Paul or Eric might be able to shed more light on the subject.
NOTE: Ray did mention that his performance greatly improved, but I suspect his drum may have been quite damaged to begin with?
All the best resolving your problem.