Polissage (buffage) de table au polyuréthane

beluga écrit: J'ai essayé cet ensemble de Lee Valley, il y a quelques temps, sur un dessus de table.

Micro-Mesh

Je ne me suis même pas rendu au plus fin, et j'étais plus que satisfait !!

Bebye !!

bobmaxja écrit: Tu trouveras tel réponse ici dans ce superbe manuel de Targets
Voir section
The Final finishing steps

Jerry Works

Yankee écrit: Et oui ca se buff du polyuréthane.....Il t'explique comment ici

One of the well know brands is a Mirka
product called “Abralon”. I use them from
500 up to 4000 grit. Most often I use
them in 6” (150 mm) round pads that stick
to the hook and loop backing on my random
orbit and dual mode sanders.
Use a light touch, slow down the speed if
your sander has variable speed, and
keep the sander moving. You are not trying
to remove material from your finish,
only to take off and dust or other spots
that leave it less than perfect.
Start with the finest (highest number)
Abralon pad you have and see if it removes
these dust spots. If not, move to
the next courser pad and see if it removes
them. Once you find a grit that
takes these dust spots off, then progress
to the next finer grit. Be mindful of the
gloss you are building up. You can
quickly take a satin or flat finish to a
higher gloss than you may want.
If you do get too much gloss for the look
you are after, you can soften it by using
the next courser Abralon pad, or by rubbing
it with fine steel wool, or by applying
a wax like Briwax. While the wax imparts
a shine, it is a soft shine that most associate
with a desirable patina so they don’t
think of the surface as “shiny” only “silky.”
Never use steel wool between coats with
water based finishes. Microscopic particles
of steel left behind will rust under the
surface creating marks that cannot be
removed. On darker woods they are
harder to spot, but on light colored woods
they will raise havoc with an otherwise
perfect finish. It is OK to use the steel
wool after the final coat has cured and, in
the right hands, steel wool can impart a
beautifully soft flat surface. Just be mindful
that the steel wool is adding very fine
scratches that cause light to refract rather
than reflect off of the surface rendering
the flatter look. If you over do it the surface
simply looks scratched.
Another “trick” with the Abralon pads is to
burnish raw wood. Sand up through the
finest grit you have in sand paper and
then progress up through the finest grityou have in Abralon. If the
wood has much natural resin,
you will be amazed at the
deep patina you can achieve.
Of course, this burnished raw
wood has no protection so that
patina will be short lived if it is
touched, but the effect is stunning.
If you do want to protect
it a bit, just use wax. Use
three coats of a quality wax
like Briwax and the patina will
remain so long as the piece is
not handled much

On the other hand, if what you want is
that incredible deep mirror like gloss of a
grand piano or high end guitar, it is far
easier to do than you might imagine.
These water based finishes are perfect
surfaces to buff and polish. These products
are similar in many respects to the
clear coat on a modern automobile so the
same buffing and polishing compounds
used on the car finish work just as well
here also.
You can use any brand but the one I particularly
like is made by a family owned
German company called, “Menzerna.” It
is the largest supplier of polishes and
compounds to Germany's automakers
and is considered by many to be a world
leader in abrasive and polishing technology.
Start by letting your finish cure for several
days - a couple of weeks is even better,
especially with the urethanes. Then,
sand the finish perfectly flat with 400 grit
paper. You do not want to sand through
the finish, only to take out all of the surface
irregularities. You want an even dull look to the surface much like one seeks
while “color sanding” or “block sanding” a
car finish.
Once the surface is nice and flat and
evenly dull, you can start the buffing and
polishing process.
I I use my Festool RO150 dual mode
sander with the rotary mode selected. It
is really a rotary mode with a simultaneously
rotating pivot point so the pad
moves in a complex pattern a bit like the
child’s toy called a “spirograph” from
years ago. I replace the backing pad with
one specially designed for felt pads and
sheepskin bonnets.
You can use any rotary buffer you wish as
long as you can slow down the speed so
as not to burn the finish with the rubbing
compounds.
For this example I made up a test panel
of Brazilian Cherry with inlays of both
Maple Burl and Blood wood.