Everything you need to know about Sanding!
here for a printer friendly version of Tip
do you begin?
you need to familiarize yourself with the four most common
types of abrasive materials available to the modern day woodworker:
Flint, Garnet, Aluminum Oxide and Silicon Carbide.
is the least expensive - and least durable - of all abrasives.
Made from crushed quartz, it's usually off-white in color.
Because it's so inexpensive, it's best used for removing heavy
layers of paint, wax or other finishes - or for sanding really
resinous or gummy surfaces. When the abrasive
loads-up with these clogging materials, just throw
your sheet away and start with a fresh one. Since flint is
really dull in comparison to other abrasives and has a tendency
to leave flint dust embedded in the grain of the wood that
can cause a chemical reaction with certain synthetic finishes,
it is NOT recommended for any type of finish sanding.
ALUMINUM OXIDE is a synthetic abrasive, made from fusing
bauxite in an electric furnace. It can be either red, brown,
gray or black in color and offers very sharp grains that will
out-wear Garnet abrasives. For this reason, it is the preferred
abrasive for most machine sanding operations and is clearly
the most readily available of all abrasive materials.
is an excellent natural abrasive that will leave an extremely
smooth finish. For this reason, professional furniture and
cabinetmakers prefer it for final, finish sanding operations.
Although it is not a very hard material, it is
probably the sharpest of all abrasives, with particles that
have a tendency to fracture during use. This fracturing process
is constantly exposing sharp, new edges... and that's why
it cuts so smoothly. Garnet paper is almost always reddish
CARBIDE is the hardest and most expensive of all abrasive
papers. It is a synthetic product, made by heating silica
and carbon to form a crystalline substance that is almost
as hard as a diamond and very brittle.
usually only available in fine to ultra-fine grades. For that
reason, it is not well suited for sanding unfinished woods
and is best reserved for wet or dry finish sanding of paints,
varnishes, urethanes and lacquers. Charcoal colored silicon
carbide paper is used for both wet or dry sanding, while light
grey colored papers are for dry sanding only.
on to...How Are Sandpapers Graded?
Back to Introduction