technical manu al table of contents - Jamestown Distributors

Question :
For sanding purposes, what is the effective drying or “cure” time in between coats of
varnish or does it vary depending on the relative temperature?
Answer:
Manufacturers publish a theoretical “dry time” based on a predetermined temperature
and humidity level. Certainly, if the conditions are beyond these levels in either direction,
the dry time will be effective. Generally speaking, a single-part paint or varnish is safe to
sand after 24 hours. This will ensure that the finish is hard enough to withstand the
abuse of a good sanding. This does not necessarily mean that the material will be easy
to sand or, that the sandpaper will not clog. Better quality varnishes will contain more oil
and therefore, will simply take longer to really cure.
Question:
For the last two or three coats of varnish, how 'fine'
should the sandpaper be and would you suggest that the last coat be
thinned or not?
Answer:
400 grit wet or dry is the absolute finest grit that we would ever recommend. In fact, I
usually lean towards 320 grit. Anything finer than 400 grit does not create enough “tooth”
or mechanical bond to ensure adhesion.
Thinning the final coat is the applicators decision entirely. If you have been building with
full strength (my preference) and the varnish has been laying down o.k. then by all
means continue with full strength. If however, you are having problems keeping a wet
edge or, it is just not behaving, then consider a splash or two of brushing thinner. Only a
large dose of thinner (15% or more) will affect the ultimate strength and quality of the
finish.
Question:
I have read in a number of places over the years about a varnished
finish that is either hand-rubbed or has a hand-rubbed effect or look to
it. Could you explain what that means? Is it a special procedure and, if
so, how is it accomplished?
Answer:
In the old days, the only way to obtain anything except a high gloss finish in a varnish
was to “rub it by hand”. Obviously, it was a labor intensive, time-consuming procedure.
These days, we can reproduce that look in a single (or two-part) part finish right out of
the can. “Rubbed Effect” varnish describes the degree of gloss. Somewhere between a
semi gloss, satin or eggshell finish. This degree of gloss is perfect for an interior
although it is sometimes used in exterior applications. Rubbed Effect Finishes are