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By Jim Hingst
Paint driers (dryers) accelerate the chemical reaction that occurs
as an oil paint cures. Artists, house painters and sign painters have used
driers, such as Japan Drier, for years to accelerate drying. These driers can
be useful when you need to paint two coats in one day.
“Driers
are also useful if you are in a hurry lettering a sign or a truck,” says veteran
sign painter, Joe Balabuszko. “Driers save time if you want to outline the copy
the same day you paint the letters. They also same time if you are repainting
an existing sign.”
Joe
explains that after tracing the outline of the lettering with an indelible
pencil, you can paint the background color with a little drier in it. The
indelible pencil shows thru the background color. “The drier allows you to paint
the lettering the same day,” Balabuszko says. “The time you save is money in
your pocket.”
Here’s how paint driers work. Oil paint consists of drying oil and
pigment. The paint cures as the resin or binder, such as linseed oil, polymerizes
and then cross-links. Driers work as catalysts to promote the oxidation of the
oil and to accelerate the cross-linking process, in which oil molecules join
together.
Many years ago,
driers were lead based. Lead driers were popular for several reasons. Their use
toughened the paint film, making it more flexible and more durable. Because of the toxicity of lead, other
elements have replaced it. These
materials include iron, zinc and zirconium. Some, but not all, of the driers
are colorless. Cobalt driers are bluish. Iron driers have a reddish hue.
Modern paint
driers are generally manufactured by dissolving a metallic salt in a
hydrocarbon solvent, such as mineral spirits, to form a metal soap. The
metallic salt results from a chemical reaction between a metal and an organic
acid, such as hydrochloric acid or sulfuric acid. In this reaction the metal
replaces hydrogen (H₂) in the
acid. In other words, the result of the reaction is a metallic salt and
hydrogen gas..
While the drier
helps the paint to harden, misuse of the product has some potential
disadvantages. These disadvantages include embrittlement of the paint film
leading to cracking; darkening of the paint; and skinning over of the paint
resulting in wrinkling.
● Read the manufacturer’s
instructions and safety precautions before use. Do not exceed the recommended
amount. Typically, you should not add more than 5% of drier to your paint.
● Some paints dry
well on their own. Only use a drier unless absolutely needed.
● Do not mix in
the drier until you are ready to use the paint.
● Do not add more
than one type of drier to the paint.
Do You Have Questions or Comments?
About Jim Hingst: Sign business authority on vehicle wraps, vinyl graphics, screen printing, marketing, sales, gold leaf, woodcarving and painting.
After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.
Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer. Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.
Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for publications, such as Signs Canada, SignCraft, Signs of the Times, Screen Printing, Sign and Digital Graphics and Sign Builder Illustrated. He also posted more than 500 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published. Vinyl Sign Techniques is available at sign supply distributors and at Amazon.
© Jim Hingst 2018
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