REPRINTED FROM TYPE & PRESS / COURTESY OF APA

The Great Type

Blight Mystery


By Fred Williams
Editor-Publisher, Type & Press
Winter 1979


Does your type have a dark gray powder adhering to it?…Has the once shiny type body turned to a dull color?…Does the face of the letters appear as though it has been nibbled on by type lice?…If so, your type is a victim of Type Blight, Corrosion, or Rusting. Whatever the terminology–it's a deadly affliction to plague the hand comp.

Type Blight is the gradual decomposition of type metal into a dull gray powder. More prevalent on old type, new faces aren't immune for long. Affecting strip, Mono and foundry faces, the corrosion may in time attack the printing surface of the face and turn it into a rough textured area that will not print sharply.

Metallurgists at the U.S. National Bureau of Standards have been unable to find any mention of the problem in technical literature in their libraries.

Printers surmise the "rusting" could be caused by an electrolytic action between metals of the alloy rather than oxidation and is difficult to stop. Moisture in the air coming in contact with the metal alloy starts and promotes the electrolysis, usually attacking the exposed areas. Two pieces of type that are stuck together may have shiny surfaces where in contact, although all the exposed parts have been attacked.

Presumably the oil in printing ink tends to hinder the blight and some printers keep a coating of ink on fonted up type. Used type may have a smooth, shiny printing surface while the rest of the piece of type may be covered with the corrosion. In the same case, type that has never been inked may have had its face destroyed. Oiling the affected type does not seem to help in arresting the treacherous blight.

Back row letters in lower cases of type cabinets seem to be more afflicted than others, probably due to moisture from the wall, or because those letters get less use. Some comps rotate type so all letters will receive protective coatings of ink and solvent.

Often corrosion is seen in the form of fingerprints, making it obvious that perspiration probably can initiate Type Blight.

Dust that settled on type also may be a source of trouble as it adheres to the type, discoloring it, causing the start of this cancer. Dust proof type cabinets should help eliminate this cause.

Problems also may be encountered with zinc cuts corroding, especially if they have been wet. If badly affected, ink will not take to their surface. Not all cuts seem to be susceptible, even though stored in the same environment.

Some printers have found that soaking type or cuts in lye solution may soften the rusting. On zincos, bad spots may remain discolored after treatment, but rust will come off with brushing and won't return after treatment.

A solution of lye can be mixed and the type placed in it to soak, the time depending on strength of the solution. Liquid or powdered drain cleaners are satisfactory–liquid cleaner, straight form the bottle, requires about 24 hours to soften badly affected type.

For treating zinc cuts, care is required as they are usually wood monted and must not be soaked too long. Some printers use a stronger solution, about 1/4 tablespoon in a 1/2 pint of water. Immerse cuts into 1/4" deep liquid. The wood will not get wet enough to cause damage. About one to two hours should be sufficient to remove corrosion. Be careful in the handling of lye–it will burn the hands and splashing into the eyes could cause blindness.

Don Winter of the Los Angeles Typefounders says: "Our experience has been with type that has been damp at one time. Other wise, we have had type in our cases over 30 years with no signs of corrosion. Occasionally we do come across a piece that has "rusted" alongside of type in good condition, for no apparent reason, we have no answer. Climatic conditions may be the cause."

Some printers report they have controlled Type Blight by using dehumidifiers in their shops.

Typefounders MacKenzie and Harris of San Francisco recommended a thorough washing of type after use with Phenoid plus a rubbing of type face with an electrotyper's abrasive eraser. But they report they know of no sure way to prevent "rusting." Once the typeface has become heavily pitted, there is no cure.

More on Corrosion of Foundry Type Metal
Fall 1981

(The Great Type Blight Mystery (T&P #19) evoked a number of letters from typographers. Worried, they requested a follow-up article with more information on this scourge—Ye Ed.)

Naturally corrosion of their precious type metal will cause apprehension and watchfulness of all Letterpress printers. They are constantly plagued by the foreboding thought that their irreplaceable case-hardened types may be "rusting away" while they sleep!

When type metal is new from the foundry it is protected by a coating of an anti-corrosive substance. This will usually prevent any rusting until the type is laid in the printer's case.

Then if any moisture is present, the rusting may begin—if preventative remedies are not instituted promptly, the types will probably be "eaten alive" and be useless for any class of printing.

Shops in localities where the climate is damp are apt to be more afflicted with corrosive damage than those in areas that are dry and hot.

Damp basement shops or those in seaside areas are usually always infected with type rusting unless preventative precautions are maintained.

Printeries with cement slab floors that have been poured directly on the bare ground without a thick moisture barrier, will be more likely to have type blight than ones with wooden floors and a crawl space. Attic and second-story print shops are less prone to the blight pest.

To check for possible corrosion, slide out the bottom case in one of your type cabinets. Examine a seldom used character such as an ampersand, diphthong, question mark, etc.

This plague will appear as a gray scum or powder on the face and sides of the type. If the face is pitted it will be unfit for use.

Type metal, composed of dissimilar elements (lead, tin, antimony, copper), will, when exposed to moisture, cause galvanic action or electrolysis.

Types used often will seldom corrode. The residue from the ink and type wash forms a protective film which prevents the attack of the devastating blight.

Flash drying solvents or leaded gasolines may contain ingredients that will initiate this corrosive action. White gasoline will be the safest to use.

Corrosion may appear on type forms that have been wet from mouse or rat urine as well as from coffee cups or soda pop bottles that have been carelessly put on type forms.

In the old hand-set newspaper days, type blight never was much of a problem. After the run was finished forms were wiped clean with benzene. Then they were scrubbed with a stiff brush using lye water. This was followed by rinsing in clear water.

Eventually the types became so blackened that no self-respecting type blighter could be found within 100 picas of it!

Preventive measures to combat the corrosion menace are:

1. Use steel, dust-proof, masonite -bottom cases in closed cabinets in place of cases in open racks.
2. In damp basement shops, if possible locate cabinets near furnace or floor heater.
3. In concrete floor shops keep type cases up off the floor.
4. Maintain an even temperature in printeries in damp areas.
5. In new shops, insulate the walls, ceilings and floors. Lay a thick moisture barrier before you pour concrete slab floors.
6. Constantly rotate type to allow all characters to receive protective residues or ink and type cleaner.
7. Install humidifiers in shops and run them at all times.