Even where you are merely touching up
sound boat varnish, the surface
must be sanded to provide a key so the new varnish will adhere well.
Varnish should always be
sanded with a fine grit, 150 or
less, a course paper will leave scratches which will be impossible to
For boat varnish work, always
sand along the direction of
the grain of the wood and not across it, so it really needs to be done
Where old varnish is lifting,
blistered or has flaked it
is better to take it all off and start again than to try to patch it
Start off with a long handled
scraper, this is the type
of job they are designed for.
If there is a lot of thick
varnish to be removed you
could resort to a hot air gun and a hook scraper or if you are feeling
I have found that chemical
strippers are messy, hazardous
to use and work out quite expensive, I'd rather take my chances with
Once you have got the old
varnish off, or if you are
starting from bare wood you then need to give the area a good
"I can't wait for the oil wells to run dry, for the last gob of black, sticky muck to come oozing out of some remote well. Then the glory of sail will return." (Triston Jones)
the surface of
the bare wood the better will be the final finish.
Finish off with a cabinet
scraper to get a really fine,
Take care if you are sanding
down plywood, the last thing
you want is to go through that top veneer.
Before beginning varnishing
is imperative that you clean off all traces of dust.
A vacuum cleaner is the most
effective method for
removing sanding dust.
Then finish off by wiping the
surface with a 'tack
rag', a lint free cloth damped with white spirit or denatured
Where the wood has become
discolored you can try using a
chemical wood cleaner, but they are not something I have had any
I have found that wood
cleaners merely bleach out the
natural color of the wood without entirely removing the stain, but then
I didn't read the instructions properly.
If you intend using masking
tape use the blue plastic
variety or the bright colored electrical tape, it can be left on for
still peel off cleanly.
There may be occasions when
you wish to remove unsightly
the surface before re-varnishing.
This is usually done with
bleach solutions such as
acid, just be aware that these are rather nasty chemicals.
I'd just like to point out that I'm
referring to the type of
stain which soaks right into the wood and dyes it.
There are a number of propriety wood applications which promise
enhanced UV protection but which are basically pigmented emulsions
which coat the wood, in my humble opinion a coat of paint would look
But then I have never had a very satisfactory result from using
They are not easy to use and the colors will alter as they dry and with
time and UV light.
However if you really
feel you must use a stain, the wood must be completely bare with no
varnish grease etc to prevent the dye soaking
And you should have
completed all the surface
preparation, sanding etc.
Try out the stain on a
scrap piece of the same
wood first to check how it is going to look.
These dyes soak into the
wood, so once they are
on you'll find them difficult to alter, you might be able to sand
them back a certain amount.
Most dyes are spirit
based so they can be diluted
with a solvent or white spirit.
For best results apply
liberally then wipe off
The stain must of course
be completely dry before
you begin varnishing.
Advocates say that it is a
quicker method of applying
boat varnish than brushing, yet to get a good finish requires two
rolling on the varnish while another follows closely with a bush to do
And all the awkward spots and
edges still need to
Still, I suppose that if you
have one or two helpers who
are not very good at brushing it might be a good way to get everyone
The person doing the 'tipping'
should be the
best at using a brush.
The person on the roller wets
it out thoroughly, taking
care not to spray drips.
The 'tipper' then follows
lightly brushing it out.
It is important that the two
work in consort, so that the
tipper can keep up with the roller and always be working on wet
and tars are probably the oldest form of wood protection used by boat
They are particularly
useful for working boats
which spend a lot of time in wet conditions.
Unlike boat varnish they
remain soft and move with the
wood so they don't crack.
And because they penetrate
become part of the wood surface they don't have to rely on a surface
so they won't peel.
They won't give the same high gloss as varnish, however, many folk
(including me) prefer this look as well as the lack of fuss
will however darken the
wood and the traditional
straight wood oils will soon become dull when exposed to the
For the pleasure boater who
likes the oiled finish there
are several products which combine the benefits of a natural barrier
finishers which will retain the shine.
They are two part products, a
penetrating oil to
waterproof the wood then a top layer which bonds and provides a lasting
Oils can be easily applied by
brush, a cloth or with a
pad of synthetic wire wool.
Initial coats of Tung or
linseed oil should be thinned
and after each coat excess oil should be wiped off with a rag.
I am perfectly aware that the majority of Wooden Boat aficionados are sensible folk. However, I need to point out that I am an amateur wooden boat enthusiast simply writing in order to try to help other amateur wooden boat enthusiasts. And while I take every care to ensure that the information in DIY Wood Boat.com is correct, anyone acting on the information on this website does so at their own risk.