| Dear Ms. Builder: I moved into an older house that I plan to fix
up myself. It has beautiful natural woodwork that needs refinishing. I am
confused about what sandpaper to use and when. What paper is best? - Connie P.
Dear Connie: When you go to a home center or major hardware store and
finally find the sandpaper aisle, the choices are staggering and confusing.
Each package is listed with much nomenclature, specifications and plain old
marketing hype. It can be truly overwhelming and confusing.
Although this is probably not what you want to hear, there really is not one
best type of sandpaper for all jobs. The most effective type depends on the
material that you plan to sand and the end result that you desire. In your
case, you probably want a professional-looking slick glossy finish.
The first major categories of sandpapers are open or closed paper. Open
paper has only about 70% grit coverage which leaves spaces between the
particles. This works well with wood. The open spaces keep the sandpaper from
loading up and clogging with the wood dust. Closed sandpaper is better for use
on metal or other hard materials.
Next you must determine the grit to buy. A smaller grit number means a
larger, more coarse grit size. The number refers to the number of holes per sq.
inch in a sieve. In order to get 220 holes per sq. inch, the holes must be
smaller than in a 60 holes per sq. inch sieve. Smaller holes allow only smaller
particles of abrasive to pass through.
You will often start out with a coarse 60-grit paper and sand across the
wood grain. This removes a lot of wood quickly to remove any small nicks and
scratches. Next you can use a 100-grit paper and sand with the grain.
Prior to finishing, use a 180-grit paper for a smooth surface. If you have
plenty of time, light sanding with 220-grit paper will yield a glass-like
surface. This is also a good grit to use between coats of urethane.
Your final selection decision is the type of grit. Sandpaper does not
actually use sand. There are four basic abrasive grit materials and each has
its specific advantages for various materials you are finishing.
Aluminum oxide is the most common material you will find and it is one of
the best for use on raw and painted wood. It usually has a light brown color.
It is inexpensive and as you use it, the aluminum oxide particles fracture.
This is good because it continuously creates new sharp edges.
Red garnet is another grit material that is often used on wood, especially
for the final finishing. It is orange or red in color. As you use it, the
relatively soft abrasive particles tend to dull (not self-sharpening like
aluminum oxide). This dulling makes it easier to get a mirrorlike surface on
the wood prior to finishing with urethane.
The other two types of grit that you will find are silicone carbide (black)
and ceramic (reddish brown). Silicone carbide, is very hard and self sharpens
somewhat and is best for metals, plastics and other synthetic materials.
Ceramic grit is most often used on power belt and pad sanders.
Although you mentioned only sandpaper, there are some fairly new sanding
"sponges" that can be washed and reused many times. These are
comfortable to the hand and are ideal for sanding wood with curved surfaces.
Since they form to curved surfaces, they tend to provide a more uniform sanding
action.
They sanding pads are available in many grits just like regular sandpaper.
If you cannot find them, here are two companies that make them - Surehold
(800-881-4495) and Norton (800-551-4415). Surehold also offers a special
project kit that contains various grit sponge pads, glue, glue remover and a
general-purpose file.
Send your questions to Ms. Builder, 6906 Royalgreen Dr., Cincinnati, OH 45244 or
visit www.dulley.com/msbuilder.
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