
Varnishing
People often ask, ‘What is the secret of
varnishing?’ Unfortunately there’s no easy
answer. But if you follow these guide lines and are patient, you will
end up with varnish
that will be the envy of everyone. It can be done, but you must realise
that the more
effort you put in, the better the results will be. Good varnish takes a
very long time.
Tips
Always sand along the direction of the grain.
Always varnish along the direction of the grain,
Use a block with sandpaper where ever possible,
For the last coat always use a new tin,
Use only quality brushes,
Never use varnish straight from the tin. Decant into another container,
Always buy 3M sandpaper. You will save time and money,
Always wait 24 hours between each coat,
Always sand between coats,
Always use a tack rag.
Preparing the surface
Use something like 120 grit sand paper on bare wood. This is not so
coarse that it
leaves visible scratches, but it will leave a nice
‘key’ for the first coat of varnish. Use a
block and sand in the direction of the grain.
Cleanliness is important. Less so in the early stages, but the nearer
you get to your
final coat the more you must pay attention, not only to the actual work
but what is
around it. If there is a huge pile of sawdust nearby, vacuum it up.
Windy days are best
avoided.
Add 50% thinners to the varnish. This allows the varnish soak into the
wood. Apply the
first coat, leave 24 hours.
Sand very lightly with 280 grit. Apply the second coat, mixing 75%
varnish to 25%
thinners.
Sand a bit harder with 280 grit. Use a block and change your paper
often.
From now on, you must add the least amount of thinners as possible to
the varnish.
The object is to build the layers of varnish as thickly as possible.
Varnish will only last if
there are at least 8 good thick coats. Allow 24 hours between coats,
and sand using a
block and 280 grit between each coat. Don’t worry about
getting a great finish at this
stage. When you have 6 coats your varnish should be looking pretty good.
When you get to your final coat, make sure your brush is very clean.
Wash it with plenty
of water and washing up liquid, rinse well and allow to dry. Hang the
brush up (that is
what the hole is for in the handle). When it’s dry, you can
vacuum it to make completely
sure the dust is removed. You will always get a much better finish if
your last coat is
from a freshly opened tin. Old varnish needs more thinning, so the
resulting coat will be
thinner, offer considerably less protection and will show up your brush
lines.
The most important thing for a dust free finish, asides from a clean
environment and
brush, is to make sure the surface you wish to varnish is dust free.
Dust settles very
quickly on a flat surface. It may look spotless to you, but
there’s only one way to be
sure and that is to use a tack rag. You should be able to buy these at
your local
chandler. Wipe the surface with it and any dust will stick to it.
You must work swiftly. Use a small amount of varnish on your brush and
make more
trips to the pot. Do not spend ages brushing the varnish around. It
will do you no good.
The best varnish is created by using the biggest brush possible, with
very little
‘working’ of the varnish. When applied correctly,
the weight of the varnish will drag out
your brush lines like magic. This does not happen instantly. You must
get into the habit
of varnishing without looking back. After a few minutes it will have
settled. If you miss a
bit. Tough, do it later. Touching up varnish that has lost
it’s wet edge never works. The
same applies to insects that land in it. Leave them. They will brush
off later and you
probably won’t see their legs stuck in the finish. Varnishing
a flat surface means you
can apply a thicker coat of varnish than if the surface was vertical.
If possible, wait for a week or two before attempting the last coat.
This will allow the
coats underneath time to harden.
A quality brush is only expensive if you don’t clean it and
have to throw it away. A well
looked after brush will last years. Always clean your varnish brush
after each use, in
plenty of white spirits. Then wash with washing up liquid and plenty of
water. Cleaning
a brush properly should take a good 5 minutes.
There are three types of brush that can be particularly recommended.
One is a
badger, the same
bristles that are often found in shaving brushes. Another natural
bristle brush is the Purdy Ox Hair. Put simply,
this is the Rolls Royce of varnish
brushes. The last brush is also made by
Purdy but it is a synthetic one. There are two
sets of bristles, one set, short and thick and the other long and fine.
The best of both
worlds. Expensive, but beautifully made and easier to clean than
natural bristles.
A note on sandpaper. Always use 3M Tri mite. Anything else just
won’t do. Cheap
paper clogs really quickly, which renders it useless and so you have to
use more,
which takes longer and costs more. Do yourself a favour and
don’t compromise here.
One could say the same about Varnish. Use Epifanes varnish which is great.
There
are other good brands but Epifanes stands out. In short you get what
you pay for.