Hi Folks,

My first post to the group...

I have recently purchased a random orbital sander and am happier than a
hog in mud. It gives an incrdible finish and handles beautifully.
However I have noticed some funny things on my latest project out of
white oak.

Using a 60 grit pad hardly removes wood at all. It almost burnishes the
surface giving a small ripple but not removing much stock. I tried some
180 grit and it cuts like a hot knife through butter! I smoothed the
whole surface (80cm *60cm) that I am working on in a few minutes! Took
out multiple small planing tearouts at least twice as fast as the 60
grit pad??

Has anyone else experienced this?

On a previous project out of a local African hardwood 'Kiaat' I also
noticed that the cutting rate with 180 seemed incredibly fast...
Happy woodworking
Brent

"Brent" wrote in message I have recently purchased a
random orbital sander and am happier than a
hog in mud. It gives an incrdible finish and handles beautifully.
However I have noticed some funny things on my latest project out of
white oak.

Using a 60 grit pad hardly removes wood at all. It almost burnishes the
surface giving a small ripple but not removing much stock. I tried some
180 grit and it cuts like a hot knife through butter! I smoothed the
whole surface (80cm *60cm) that I am working on in a few minutes! Took
out multiple small planing tearouts at least twice as fast as the 60
grit pad??

Has anyone else experienced this?

On a previous project out of a local African hardwood 'Kiaat' I also
noticed that the cutting rate with 180 seemed incredibly fast...
Happy woodworking
Brent


There are different kinds of sand paper and some will load up quickly. If
the 60 grit is not an open coat type sand paper it may be loading
prematurely. Also are you sure the 60 is not really 600? :~)

Leon wrote:

There are different kinds of sand paper and some will load up quickly. If
the 60 grit is not an open coat type sand paper it may be loading
prematurely. Also are you sure the 60 is not really 600? :~)

I'm really sure that it is 60 ;-)

the 60 grit is the dark red/brown paper which does seem to have a
rather heavy binder to hold the grit in place. The 180 I used is a
white paper. What are the differences and what is better to use?

I've only ever used a normal orbital and used 1/3 sheets of standard
waterpaper. Never used the hook-and-loop stuff before...

Brent

Brent wrote:

the 60 grit is the dark red/brown paper which does seem to have a
rather heavy binder to hold the grit in place. The 180 I used is a
white paper. What are the differences and what is better to use?

Sounds like Leon hit on your problem.

SFWIW, I use Klingspor PS33, an open coat paper they sell to the
furniture industry.

It is H&L.

Lew

"Brent" wrote in message
ps.com...

Leon wrote:

There are different kinds of sand paper and some will load up quickly.
If
the 60 grit is not an open coat type sand paper it may be loading
prematurely. Also are you sure the 60 is not really 600? :~)

I'm really sure that it is 60 ;-)

the 60 grit is the dark red/brown paper which does seem to have a
rather heavy binder to hold the grit in place. The 180 I used is a
white paper. What are the differences and what is better to use?

I've only ever used a normal orbital and used 1/3 sheets of standard
waterpaper. Never used the hook-and-loop stuff before...

Hook & Loop should not make a difference over PSA other than being able to
reuse the paper after changing grits. Open coat sand paper is usually
Aluminum Oxide and tends to do better when sanding wood. Open coat sand
paper is usually white in color and is likely what you are using in the 180
grit.
Also keep in mind that sand paper wears out before it looks worn out. The
easiest way to check is to feel the cutting surface with your finger and
compare to new paper. Typically sand paper will only last about 10-15
minutes with constant use.

Thanks for the help guys!
Makes sense...

Brent

"Brent" wrote in message
oups.com...
Thanks for the help guys!
Makes sense...

Don't get all the posts through my server, so this may be a duplication.
The color is from the type of adhesive used. Resin-on-resin is normal with
the reddish, and holds the grit firmly to a heavier backing. It wouldn't be
worth much on a thinner backing, because it would crack with the flex.
Thinner backings use single coats and other stuff.

In addition to open and closed coats, you also have stearated and
non-stearated, so things do get a bit more complicated. Then there's the
fact that hook-and-loop papers have to rely on their own stiffness, while
PSA can count on help from the pad, and so forth.

http://www.woodzone.com/articles/sandpaper/index.htm Shallow, but
informative.