Stuborn sanding marks

[William Bachtel]

Dok Yaker above answered that question, (What is the very best sand paper) and he added a link to it.

[Bill Jobe]

So he did.
My appologies, Dok Yager, and thanks for the link.

[John K Jordan]

You got some very good advice so far. I learned quickly to use good paper - I personally like Klingspor Gold in rolls but there are many others. Paper from HD/Lowes/hardware store would be my last choice.

On most pieces, especially open-grained wood like walnut, I like to apply a coat or two of sanding sealer before sanding. Either shellac or lacquer-based sealer is fine.

When I sand on the lathe I stop the lathe after every grit and sand by hand across the other scratches until they are gone. Think about it: if you can't remove, say, 220 scratches with 220 paper you will never remove them with 320!! (At least not easily)

When sanding by hand with all but the finest grits I often like to use a Magic Rub eraser as a small, flexible sanding block. But always without much pressure. When held in the hand, if the paper gets hot you are pressing too hard. Too much pressure with coarse grits can create deep sub-surface deformation almost impossible to remove, almost as bad as tear out. Too much pressure with intermediate and fine grits can cause checking in some woods from the heat. I learned that the hard way on my 3rd bowl!

I rarely power sand but mostly by hand and primarily with the lathe off. With cleaner cuts you can start with finer paper. I don't even have any coarser than 80 and don't even use that - I rarely start with coarser than 220 or 180 in worst cases. If I have to power-sand I do so with a tiny Grex random-orbital sander at a very low speed using 1" or 2" disks.

That said, instead of coarse sand paper I use small hand-held curved cabinet scrapers. These leave an amazingly good surface on bowls, platters, and forms. Much or most of my scraping is with the lathe off. After using the hand scrapers I can often START with 400 grit paper and sometimes with 600 or finer on smaller turnings.

I would absolutely use cabinet scrapers on a piece like you show, probably one with a flat edge to smooth the convex areas, with the lathe turning very slowly. They are available from woodcraft and elsewhere and are sharpened like conventional flat cabinet scrapers.

JKJ

[Doug Reesor]

I alternate between the 2 or 3 inch diameter pad sander on my drill and straight sand paper. That way as I step up to the next level of grit sandpaper you can see that all the lines of the courser fit are eliminated. Also, I use my trouble light to shine from the back of the piece as I rotate to inspect whether I have finished each grit before moving up a level. The pad sander makes the marks at a distinct angle to the regular paper and they can be easily seen.

[John K Jordan]

...Also, I use my trouble light to shine from the back of the piece as I rotate to inspect whether I have finished each grit ...

Doug, you make an excellent point about the lighting, one often not addressed. Broad, diffuse light such as from a series of long fluorescent bulbs overhead, or worse, from behind your head, makes scratches harder to see. (Worst of all is a headlamp.) Light that is too diffuse or coming from too close to the eyes also hurts truning in another way - it makes it harder to see and evaluate the compound curved surfaces we make in nearly every turning.

The best lighting to evaluate scratches is a "point" source, a light from a small, bright source, ideally at a glancing angle. This makes a shadow in the bortom of the scratch grooves and makes them much easier to see. A single bright light like your trouble light or a bright LED handheld is ideal.

I find that using several small but bright lights positioned around the work is a good compromise for general turning. I use several on swing arms or goosenecks so I can reposition them as needed. I often position one low behind the work and turn it on as needed (but I need to fix it somehow to keep the small reflector from filling up with shavings.) Besides helping me see the scratches, they let me better evaluate the surface curvature. I do have long, bright T5 fluorescents overhead for general work but switch them off while turning.

BTW, over 40 years ago while exploring caves I learned the value of using a glancing light where possible instead of a headlamp. A headlamp was invaluable when climbing or when both hands were otherwise occupied, but as the sole light source it removed shadows and wiped out my depth perception - it was hard to see small rocks and uneven ground. Glancing light from a handheld flashlight was far better. This is the same reason light from a strobe mounted on the camera makes a horrible flat photo compared to lighting from off to the sides.

JKJ

[Bill Jobe]

BTW, over 40 years ago while exploring caves I learned the value of using a glancing light where possible instead of a headlamp. A headlamp was invaluable when climbing or when both hands were otherwise occupied, but as the sole light source it removed shadows and wiped out my depth perception - it was hard to see small rocks and uneven ground. Glancing light from a handheld flashlight was far better. This is the same reason light from a strobe mounted on the camera makes a horrible flat photo compared to lighting from off to the sides.

JKJ

And red eye, or in the case of wood, glare that prevents viewing the entire piece.