Hi Folks,

Even though I sand to 800 grit, cocobolo still shows sanding swirls.

Has anyone used wet/dry paper in 1000+ grits with dense hardwoods like
cocobolo to eliminate sanding marks?

thanks
George

Usually sanding swirls come from skipping a grit on the progression
from coarse to fine, make sure you haven't done that.
I turn wood pens and normally sand to 4000 grit.
You can use wet/dry paper and it will help hide sanding marks. I have
heard of people who wet sand with wax, and I have tried oil. Not good
to wet sand with water. I prefer to use the paper dry.
You won't have this issue on dark woods, but the wet/dry paper is
usually black and can leave dark grit behind which shows up on light
colored woods. Wipe down with some alcohol to remove the grit before
finishing.
Brad
HardingPens.com

wrote in message
oups.com...
Usually sanding swirls come from skipping a grit on the progression
from coarse to fine, make sure you haven't done that.

Nope, it comes from insufficient sanding with a particular grit, poor
surface hygiene or excessive pressure-causing heat. There are,
theoretically thousands of "grits" between 100 and 4000, so "skipping grits"
is sort of a strange way to say 400 is going to take a long time to clear
the scratches from 100. It can do it, of course, so "skipping" doesn't
cause scratches. There are even people who claim to be able to skip all
grits prior to 220 or 320, presumably because they can create the kind of
surface most of us get here and there all through a piece.

You have to watch how you're sanding. Never press or pause, or you buy
yourself grief. No matter the temptation to press a bit harder if you have
a torn spot, resist it, because you'll end up with problems around the edge
of that place. Really bad when you start tilting a rotary sander as you can
dig or burn an edge, or the infinitely worse combination of both.

I try to minimize problems by creating a more or less random pattern as I
sand. I keep the work rotating while I use a rotary sander supported, not
by the work, but a toolrest. Since the tool marks are cicumferential, I
begin by allowing my sander contact with the spinning piece from 11 to 1
o'clock. With the sander rotating faster than the piece, it makes a scratch
pattern across the existing tool pattern, quickly obliterating it. I
normally then go to about 8 to 10 o'clock to make a more or less
circumferential pattern again. I don't want the sanding dust to collect
between the paper and the surface to burnish the wood, so I do things like
sand inside to out while in a bowl, so as to help the dust make it out the
rim. I also keep a paper towel for each grit around, stop and wipe to
inspect the real surface rather than the dust still adhering.

After that, it's repeat with the next grit in my collection, without
concerning myself with the fact that I do have 180 and 220 in one type of
paper as I go from 150 to 240 with another type. I don't like lubricated
sanding of wood, because wood is a porous medium that can harbor surprises
in the pores from my coarser grits which the slurry makes it difficult to
extract. If it's dry, my wipe, brush, or blast of air has a chance. If
it's got sticky sanding slurry in it, I'm going to have to run a couple of
solvent wipes.

Depending on the pore structure of the wood and the type of finish desired,
you may cease at 220, 320, or 400. By then there's such high potential for
heating and hardening that power sanding is often more trouble than it's
worth. Open coat stearated papers is all I'll use at 320 or beyond, because
they'll shed dust better and develop less heat from friction than their full
coat counterparts. I also use a slower speed on my sander, and sand with
the lathe off. Your experience is going to tell you which grit to start
and finish with, as well as allowable number differences in your sequence.

At your final grit, I'd take the compressed air to the piece after brushing.
Get all the random grit surprises out of the way, then set up the surface
with water or alcohol. If you've got a shiny surface, you should do this
step prior to brushing/blowing as well. You've likely packed the pores with
fine dust and heated them, causing them to contract and hold what's there.
Sand with the final grit again after cleaning and softening the surface.
Inspect with glancing light for any remaining uglies, remembering that you
want to go back two "grits" to clear them, as they are likely from two back,
hardened into the surface by the intermediate.

Hi George

You might have started with a too coarse a grit and have still some of
those marks in there, you should be able to get those out by going back
over it with less coarse paper and work your way up through the grits,
the worse problem could be that you have used high pressure with dull
paper and now you have crush marks in the wood, similar to crush marks
from a tools heel, those marks usually go deeper and are hard to sand
out, so use new sharp paper and wipe off between grits, as for wet and
dry paper, yes I have used some but only dry, I also have some 1000 to
2500 power sanding disks and use them on a finish, like CA and on dense
wood like cocobolo and other rosewoods sometimes, and then use power
buffing after that with rouge and diamond grit, I have sanded wood with
oil and regular sand paper but only in the 180 to 320 grit paper, for
sanding wet wood, but I don't really like the mushy dull end results of
that.
Just my thoughts on that, hope it's some help.

http://homepage.mac.com/l.vanderloo/PhotoAlbum12.html

Have fun and take care
Leo Van Der Loo

On Tue, 31 Jan 2006 12:26:22 GMT, "George Saridakis"
wrote:

Hi Folks,

Even though I sand to 800 grit, cocobolo still shows sanding swirls.

Has anyone used wet/dry paper in 1000+ grits with dense hardwoods like
cocobolo to eliminate sanding marks?

George,

As others have said, it sounds like you have either skipped a grit or
two, or have just not sanded sufficiently with each grit. You
shouldn't move on to the next grit until you have removed all the
sanding marks from the previous grit.

Let me caution you, when sanding cocobolo. Be particularly careful to
not generate too much heat, because this wood, like many others, is
quite prone to heat checking, and you won't remove those marks with
_any_ sandpaper.


--
Chuck *#:^)
chaz3913(AT)yahoo(DOT)com
Anti-spam sig: please remove "NO SPAM" from e-mail address to reply.


September 11, 2001 - Never Forget

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In news:George Saridakis typed:
Hi Folks,

Even though I sand to 800 grit, cocobolo still shows sanding swirls.

Has anyone used wet/dry paper in 1000+ grits with dense hardwoods like
cocobolo to eliminate sanding marks?

thanks
George

Best way to get rid of rotational sanding scratches in any wood is to sand
perpendicular to existing scratches with same grit paper till rotational
scratches a gone, then move to the next grit. You can basically stop at
whatever grit you like, depending on the surface sheen you would like. I
rarely go beyond 400 grit on the raw wood itself. I do however, go to 3000
grit wet or dry on the finish before polishing. Sanding scratches will show
less in blond woods and show more in darker woods like cocobolo & ebony.
Ebony is the most sensitive.
--
Ted Harris
http://www.tedharris.com

Hi Folks,

I tried some wet/dry paper to 1200G and some stearated paper to 1200G - no
real improvement.

Micro mesh to 12000G made the swirls disappear.

I should have originally stated that I am using kiln dried lumber which has
been acclimatized to my studio for months.

George

"George Saridakis" wrote in message
news:OHIDf.1503$8U2.730@trndny06...
Hi Folks,

Even though I sand to 800 grit, cocobolo still shows sanding swirls.

Has anyone used wet/dry paper in 1000+ grits with dense hardwoods like
cocobolo to eliminate sanding marks?

thanks
George

In news:George Saridakis typed:
Micro mesh to 12000G made the swirls disappear.

George

Not if you look closely...
the only way to get rid of rotational scratches is to sand perpendicular to
the rotational scratches. It is also a lot less work than trying to get rid
of the scratches by rotationally snading them out.
--
Ted Harris
http://www.tedharris.com

Hi Ted,

I am talking about swirls visible to the customer. I use a lit magnifier and
if I cannot see them (unfinished) under those conditions, they do not show
up after finishing. My technique on lathe sanding in the final grits is to
continuously move the paper back and forth while rotating at slow speed.
Seems to work for me.

George

"ted harris" wrote in message
...
In news:George Saridakis typed:
Micro mesh to 12000G made the swirls disappear.

George

Not if you look closely...
the only way to get rid of rotational scratches is to sand perpendicular
to
the rotational scratches. It is also a lot less work than trying to get
rid
of the scratches by rotationally snading them out.
--
Ted Harris
http://www.tedharris.com