Need help sanding Ash

[Pat Scott]

I've got a couple of White Ash salad bowls that I'm making, and I'm having a problem when sanding the inside. I can cut the inside with a gouge so that it's smooth, but when I sand it you can feel bumps across the grain. At first I thought it was because of sapwood/heartwood density, with the softer sapwood sanding away more easily. But I've also got the inner cores which are all heartwood and I still have the problem, so I know it's something I'm doing wrong.

I have the lathe running about 500-600 rpm, I started with 120 grit with the drill running a little faster than I normally would. I thought maybe with the higher lathe and drill speed that the sandpaper wouldn't have a chance to dig in as much. I'm using a 3" hard pad and trying to use a light touch with the drill.

The outside is still perfectly smooth when I get done sanding. Maybe I need to move the drill faster from side to side? I'm not going super slow, I would say I'm moving the drill at my normal speed (whatever speed that is). I'm also trying to hold the pad as flat to the surface as possible to present the broadest surface and minimize the edge from digging in.

Any suggestions? My wife says I'm the only one that would notice, but I'd like to get the inside as flat as possible. It's smooth to the touch, you can just feel the growth rings.

[Roger Chandler]

I think it is likely the growth rings being softer than the surrounding sapwood. I have done several ash pieces, and they seem to do better when sanded with a light touch and I have found with a number of softer woods that the more sanding you do, the more pronounced the undulations that end up on the piece.

If you have room to take a fresh cut off the surface with a sharp bowl gouge, then lightly sand through each grit, you may be successful on minimizing the soft/hard difference........sometimes it helps, sometimes not, but it might be worth a try. I would stick with hand sanding only and not use a drill on this one.

[Thom Sturgill]

You need a good FIRM backup pad to minimize the effect of the seasonal growth rings. This is why a lot of turners sandblast ash...

[Reed Gray]

Like Thom said, you need a firm backing pad for grits up to 180 or 220. The softer pads just won't cut as well, and won't level out ridges. Slower speeds also cut better with both the bowl and the drill. Ash can be beautiful if it has the brown center. If it is just white, it doesn't sell as well for me.

robo hippy

[Tom Wilson66]

Why sand with the lower grits if you have a smooth surface to start with? Use the higher grits to remove any raised fibers and make a uniform surface and you're done sanding.

[Pat Scott]

I am using a firm sanding pad for all grits (from The Sanding Glove). It's better than medium density for sure, but I was hoping it wouldn't dig in at all. I have considered making a shallow round bottom wood sanding block and hand sanding, I might try that.

Reed I'll try a slower speed for the lathe and drill and see what happens. I was thinking slower would allow the sandpaper to dip down into the softer areas.
Tom I started sanding with 120 grit, was that too coarse? I left the tenon on the bowls so I can remount them, use a negative rake scraper to smooth out the high points, then start sanding with 180 grit and see if that helps.

[Thom Sturgill]

Pat, my take on sanding is that 220-240 is the tipping point - anything lower can and will take away enough wood to change the form, anything higher is just refining scratches.

[Reed Gray]

The advantage to firm sanding pads is that they won't dig down into softer wood. You have a broad surface, so pressure is spread around. The firm interface pads I use, from Vince, are pretty ridged with no flex to them. The slower speeds allow the abrasives to cut better. Too fast is like spinning your wheels when drag racing. You just don't get the traction. As for which grit you need to start sanding with, that depends on the finish you get from your tools. Tear out needs a coarser grit to start with, but if there is any, I would start with 120 minimum, and most of the time coarser than that. Like Thom said, coarser grits, up to 220 are for removing tool marks and smoothing out bumps. Well, if you have much in the way of bumps, you probably need 80 grit, but some times it takes more work to remove the 80 grit scratches. Once you get to 220 or so, then you can round over a sharp edge, but not much else. Above that, you are polishing out the scratches from the previous grit. I spend more time with 120 and 180 than I do with 220, 320, and 400.

robo hippy

[John K Jordan]

This is a case where I reach for my cabinet scrapers before sandpaper. I have a variety of curved scrapers that when properly sharpened will smooth and take out tool marks even on tricky early/late wood. I've been using these for many years and they usually clean up a problem surface much faster than sandpaper (and without all the sawdust!)

I reshape the scrapers to get the curves I want, file smooth, then sharpen with a burnisher exactly like I sharpen a cabnetmaker's scraper. I use with a very slow lathe speed, often with the lathe off. Follow with perhaps 320 grit sandpaper. These scrapers have solved many problems for me, from ring and figure variations, punky wood, problem end grain, and soft woods like eastern red cedar bowls where the heat of sanding can cause checking. Great for flattening the little nub in the center.

I just used one today to smooth the end grain bottoms of a baker's dozen little weed pots I made for my kindergarteners to "make" mother's day presents tomorrow. Sanding end grain in dogwood or Osage orange, ack! - the little scraper followed by fine paper is MUCH quicker and gives me a better surface. In this case I could not use the other tool I usually use for end grain, a 3/8" round neg rake scraper, since the little vases were finished held in a relatively delicate jam chuck.

JKJ