trouble with ink on polymer plates…
Hey everyone… I am new to the world of letterpress. I recently purchased a victor excelsior 6x10. It is a nicely restored model, but seem to need some adjusting. One problem I have is when I am printing from polymer plates and the image area is small, in the middle of the plate the rollers get lots of ink on the plate and make the printed paper messy. It is very frustrating. Any thoughts???
I have added some washers to try to help keep the trucks on the rails (I hope I am using the right words)… and still there is more movement there than I think would be best. I oiled the springs that hold the rollers and that seemed to help. I would sure appreciate any ideas. Also if there is someone in the DC area that I might be able to shadow a bit I would love to see how you print and get some tips from that.
Thanks in advance!!!
Sounds like your rails are worn down and you need to add some tape to bring the rollers back to type high. Depending on what kind of rollers you have, it’s also possible the rollers have swollen with moisture. Do you know if you have composition or rubber rollers?
I would also try using roller bearers. You can buy aluminum roller bearers that lock up in each side of the chase or you can use 2 pieces of scrap photopolymer on the edges of your base (running parallel to the short sides) and a frisket to keep them from inking your tympan and/or your printed piece.
Wow thanks so much for your comments!
How would I know how much tape to add to bring the rollers back to type height?
The rollers look like rubber to me.
Where would I buy roller bearers and what is a frisket?
As you can see, I am totally serious when I say that I am new to this…
Thanks so much for your help!!!
you can either use a roller height gauge (the accurate way, try NA Graphics to buy one) or the try-and-see method of adding tape a layer at a time until the roller hit the plates right.
If it’s only on smaller graphics, though I would try the roller bearers first. A plate with more surface area will even out the pressure from the rollers and ink nicely while a smaller image area will get too much pressure when the rollers are at the same height. Roller bearers will be flank the printing image area helping to even out the pressure on the rollers.
I’m not sure if NA Graphics sells those, you could also try excelsior press. To use photopolymer bearers, just cut 2 stripes of ‘blank’ plate from your scraps and adhere them to the base.
A frisket would be something (usually a sheet of extra stock) that goes from gripper to gripper with a hole cut to allow the plate to print normally where you want it to, but the will block all the other areas from printing. I’m not sure that description helps at all…. hopefully my late night ramblings are clear enough to make sense. Think of the frisket like masking off an area when you paint. You want it to attach to the grippers because that way it will go up and down as the platen moves allowing you to place and remove the stock you’re printing on without having to remove/replace the frisket every time as well.
I really appreciate the help and am excited to try printing again!