trouble with magnesium!

I tried to print with my first magnesium plate on a Vandercook yesterday and had absolutely no success. The plate was only type and yet, no matter what I tried, I couldn’t get a nice print. My type kept outlining instead of printing. It basically looked like all of the ink was running to the edges of the individual letters and none was staying in the middle. I tried oil and rubber based ink, more ink, less ink, more and less packing, different types of paper, all kinds of things. Nothing worked, I just kept getting outlined type. I through some type on the press to make sure I wasn’t doing something wrong, and it printed just fine. Is there something special I should be doing with the magnesium? help!!!

Log in to reply   9 replies so far

From your descript, it appears some resist remains on the cut. Wash it with alcohol or laquer thinner, rinse with kerosene then dry thoroughly. Ensure the plate is well covered with vaseline and stored in an air-tight container when not in use. Magnesium is a very active material.

Actually, it sounds more like a cut that is mounted on wood totalling over type-height. Engraver’s resist doesn’t resist ink in my experience. The cut should measure .918” with a micrometer or plate gauge, or compare it to two pieces of foundry type with a straight-edge.
Careful sanding of the wooden base will take it down to the correct height; if you go too far, it can be underlaid with paper.
If the cut is high, the rollers will hit too hard, depositing ink on the sides but possibly wiping it off the surface.

Well, I gave my plate another try on a Kelsey and it worked just fine. I also measured the block and it is indeed type high. I would still like to print on the Vandercook however. I am thinking maybe the rollers were set too low? Any other thoughts?

” I am thinking maybe the rollers were set too low?”
You’ve answered your own question there. If you don’t have a roller-setting gauge (the .918” lollipop) NA Graphics has them, as may others. It is an essential pressroom tool. A sloppy alternative would be to use a piece of large foundry type as a feeler between bed and roller.

I’ve never heard this about magnesium plates. Anyone care to elaborate on the care and keeping of them?

I have magnesium cuts that have been in use for over thirty years and all we have ever done is clean them with a good type wash and store them in a dry location. Some cleaned with a blanket wash showed some discoloration but still print well. a light coating of oil or vasaline will keep the air out but if you don’t cover them dirt will stick to them and may scratch them when moved around.

Is it okay to clean them with Kerosene?

Yes, you can clean them with kerosene, But make sure they are dry before storing them.

After cleaning them with kerosene would you recommend spraying them with a spray oil or otherwise coating them with something?