Collated from newsgroup postings.
Sanding for me is still one of my biggest hurdles in producing quality work (quality at least in the sense it's the best I am capable of).
An area where I pretty consistently end up with less than perfect sanding is on the outside of bowls where two surfaces meet. Like next to a bead or at the foot. I can't seem to get right next to the raised surface as well as I need to.
I use a combination of hand and power sanding with the usual assortment of tools and papers and typically sand through about 600.
Anyone have any advice on a way to hold/move sandpaper to get these transitions crisp and perfect?
Transitions do need to be crisp.
Freshly sharpened tools are invaluable when you attempt delicate clarifying cuts into or at detail transitions.
Light, delicate, accurate shear cuts, or shear scrapes into these areas is the ideal. On bowls for instance, I'd nip in with a light, precise shear-cut wherever possible. If you do it right, you virtually eliminate ANY real sanding needs in these restricted areas.
If you do need to sand in these areas, use scissors to cut strips of sandpaper cleanly. Pull the crisp edge of the sandpaper into the area in question, and slide the sharp edge of the sandpaper back and forth as needed.
Sometimes, depending on the contour, I might fold sandpaper in half so that I've got a double sided "knife" of sandpaper I can slide into the appropriate place.
On a bowl foot, my last little cuts where shear-cuts oriented in a direction parallel to the first rim of the foot driving INTO the bottom of the bowl. That's the teensy little vertical off the bottom of the bowl that transitions into a little o-gee. My spindle gouge (freshly sharpened) was oriented out in space so the nose/toe was pointed straight into the bottom of the bowl. I eased forward taking a light teensy cut nipping that first little flat true, then STOPPED the cut when the nose of the spindle gouge touched where I thought the bottom of the curve should meet that little vertical. I then did a teensy little shear-scrape out away from that vertical to nibble the curved transition of the bottom of the bowl true to that.
I did follow up with 220, 320, 400 as described previously, but the surface was good, so it was quick.
If you're not using a high quality sand paper, try changing brands. You may also have better luck sanding with the lathe off. I have a nice magnifying lense to look through, which really helps with the detail work.
Do it (scraping) with a skew. Put it on its side, and put the point into the detail corner, first from one direction, then the other. No need to sand in here. The skew, used this way, will handle it well enough so it's ready to finish. Just use a light touch, and experiment.
I often leave a foot on a bowl, and I've had good results with a diamond-point scraper. I made mine from a flat parting tool that I wasn't using - just ground the end to a point and with the usual scraper bevel on each side of the point. So I use one side on the foot, carefully take the point right into the line of transition, then come out of it with the other side scraping the bowl wall. Takes a little practice but it works great. Like all scrapers, if it's REALLY REALLY sharp you won't have to do much sanding.
I agree with everyone who suggests using a really sharp tool to form the internal corner you're talking about. I always make a very fine cut to form the corner. It gives any piece a more professional look and also marks the edge of your sanding. However, you nevertheless often have to sand. The suggestion about cutting a crisp edge and using that is definitely the way to go. I would just add two points.
Hold the sandpaper in a curve which approximates the radius of your surface, so that you don't cut away either of the adjoining faces.
I've found that most people get into trouble by sanding with too much pressure. Sanding lightly is faster because you can get away with using coarser paper, and you don't risk ruining your shape. If you're losing grit or clogging up the paper with burnt dust, you're pressing much too hard.
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