Ink plate rough spots

Has anyone ever sanded or smoothed out a ink plate? I have a new to me 8 x 12 C&P platen press who has had some spotty inking issues. I think it may be related to some rough spots on the ink plate. Can (should I) sand the whole plate down?.. Polish it.. How do you fix the surface of a rough ink plate? THANKS!

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Are the rough spots pits or lumps? If they’re lumps they may just be old dried ink, which can be scraped off carefully (so as to not scratch the disc); if they’re lumps of rust you can give them the same treatment. If they’re pits it’s a different problem, but unless the pits are large they shouldn’t have much effect on the inking. I wouldn’t sand the disc as that could scratch it or take off metal. Fine steel wool will often do a great job of cleaning an ink disc.

Bob

how old are your ink rollers, my guess would be old ink rollers causing your problems.

B D B one more suggestion, acquire the cheapist reciprocating sander, and with a selection of the finer, down to finest wet and dry, buff the disk flat, either by working the sander against the natural rotation, to catch the driving toggle, or (with a little help) rotate the disk by hand, keeping the sander stationery. When you have given it your best shot, fairly quickly! with your steel type scale, (assuming etc) use the t\s to verify for low spots. If its low spots, see our friends comments as above, or go to plan “B” lean on your local friendly engineer and have it turned down. No disrespect to other learned friends, but wire wool rotary wire brushes etc etc obviously work, but tend to follow the existing undulations, where as the sander will bring it down flat, and then show the irregularities. Try and take a peek in your local car body repair shop, when they are flatting down an expensive car repair paint job. In essence, exactly what you are trying to achieve!!! Mick

They are rough patches - texture change on the plate. The rollers are new. It may be (after reading other post) also related to rollers slipping on the rails so I’ll address the issue there.
She seems to print better with more ink which lends me to think it’s the rough spots on the plate - but then my prints are not that crisp..
Thanks all! I have a friend down the street that does auto work perhaps I’ll bring it to him see what he advises also!

The problem with the idea of using a sander is that the felt pad on the sander will allow it to sand the low spots between the high spots. I would suggest trying a cabinet scraper (a sheet of hardened steel about 4x6 inches with edges ground true, available from a store that sells woodworking supplies) which will reveal whether the high spots are metal, part of the disc, or some deposit on the disc. Almost all manufacturers of presses machined the ink disc surface, so if it is lumpy it is probably a deposit that occurred after manufacture.

Bob

BDB, are you new to printing in general, or is this your first platen press? Rough spots on the ink disk should not affect your print quality as much as you might think. If you are new to platen presswork, it may be that you have not exhausted all the variables you can take care of easily in makeready. Things like condition of your type, older cuts inking irregularly, amount of ink on the press, the amount of packing you’re using, platen adjustment— all those things are easily dealt with in comparison to turning down an ink disk.

Of couse, see about smoothing the spots with steel wool or scraper. But make sure you understand basic makeready before taking heroic measures with that irreplaceable ink disk.

Please forgive me if you’re experienced with platen presses, but so many on BP are new to platens I thought perhaps a makeready reminder might help. (George Mills book, General Printing, is an excellent resource)

A cabinet scraper is only used on wood, and I have yet to see a wooden ink disk. If you want to make sure your platen is flat, and are willing to spend the time, purchase a machinist’s surfacing plate. Instead of a grinding paste you can use a very fine crocus cloth (sandpaper attached to a fabric substrate), and grinding oil (a specific oil that helps to float the metal particles away from the surface) wrapped around the surfacing plate. You will need to mount the ink plate in a horizontal position, and by going over the ink plate using a small circular motion you can slowly reduce the surface evenly until you get the surface you desire. A sander can bite into the suface and make it uneven, and the tendency will be to lean into the pitted areas. A surfacing plate takes time, but you will get a far superior surface with minimal loss if you do it by hand.

Paul

Paul, I beg to differ — my assumption is that the ink disc was machined from the factory and any lumpiness on it is residual dried ink. The cabinet scraper is certainly made for use on wood but will also serve to remove the ink lumps without scratching the disc. I also think that fabric-backed crocus cloth might have just enough give with the fabric to ride over the lumps. I would be more inclined to use fine(maybe 240-300 grit) wet-or-dry sandpaper with the oil. Less give. But I would first try scraping off the lumps to see if that works.

Respectfully, I don’t agree Bob. I resurfaced the entire bed of my Albion using the process I described above. It was milled at two levels and had to be brought down to one consistent one. Not having a milling machine, that became my only option. Crocus cloth works the same as sandpaper, it is just stronger, and lasts longer. If the poster above has severe rust spots on their ink disk it might be the safest way to make it level. If they have dried ink then Laquer Thinner and a fine Scotch-Brite pad will remove it without the necessity of scraping.

Paul

I have had some success removing dried ink from pads, plates and type using paint remover for metal. I have been buying it at hardware outlets. Apply and let it stand, remove with a stiff (Not wire) brush. In the case of pads, I have resorted to steel wool.
Use rubber gloves as paint remover is somewhat caustic