Selecting the Right Finishing Material
by Alan Noel
Professional Wood Finisher
In my classes there is always a lot of confusion about the words "enamel" and "latex". Also,
"varnish" and "spar varnish" are confusing as well. In the world of finishing materials,
varnish and spar varnish are the same material with one very important exception between the
two. And for those of us that have been around for lets say "a while", we see enamel and latex
on the same label which quite frankly, doesn't make sense. Here are a few tips to help clear the air.
- Spar varnish is a "long oil" varnish which dries very slowly and cures over a very long time.
This way the material stays more "supple" to accommodate the movements of the substrate
so as not to crack and fail. Use this material for outdoor furniture, boats and exterior doors
or anything that is going to be exposed to the elements.
- Varnish or "polyurethane varnish" is for interior use only and will not stand up to the rigors of
the elements outdoors. Spar can be used as an interior finish if need be but has the drawbacks
- For us old timers, there used to be only one type of paint for exterior use
and it was simply known as "enamel". This enamel was oil based and was
the only type of paint or varnish on the market. It typically
contained lead to help speed up drying, increase durability, maintain
a fresh appearance and resist moisture. In the early 1970s, lead was banned from the marketplace for health and
safety reasons. Since then, lead has not been used in any finishing materials
for the home or industry.
- "Latex enamel" shows up on the shelves as the new exterior finish with the "enamel" now consisting
of a water based latex paint with "acrylic" being added for extra durability from the elements. Not long
after, water based polyurethane appeared as well as the new "water based varnish". However it is not
recommended for exterior use.
- To simplify or to confuse even further, oil based products are now referred to as "alkyd high gloss,
semi gloss or satin/dull enamel paint" or "alkyd high gloss, semi gloss or satin/dull varnish".
As always, be sure to remove any ignition sources from the finishing area of your shop.
Visiting Atlanta? Attend one of Alan's upcoming highly informative Highland Woodworking wood
July 3 Coloring Wood
August 3 & 4 Antique Restoration
Visit Highland Woodworking's Online
Wood Finishing Supplies Department
Alan can be reached directly via email c/o Alan Noel Furniture Refinishing at firstname.lastname@example.org.
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