Getting rid of surface swirls

[Webb Willmott]

Hope I don’t lose my hair imitating Richard Raffan making a box when I turned this today. It finished out nicely but I can see sanding swirls upon close examination. I can rechuck it without leaving chuck marks and refinish the surface. I’m thinking the course grit sandpaper was the culprit. Also this was a practice project so any helpful advice is appreciated.

If this was you, how would you fix it?

As a side note, my friend and local mentor Gerald Lawrence stopped by the other day to give me a lesson on sharpening bowl gouges. Fortunately I had that figured out before he got here so he gave me a tutorial on roughing out green bowls using my freshly sharpened bowl gouges. He also checked out my new lathe.

He also brought me a piece of Ipe which I’m trying to figure out how to purpose and a piece of bloodwood which I made the finial for the lid of the box. It’s also funny how 2 pieces of cherry are different colors.

 

[Don Stephan]

If talking about sanding scratches around the surface of a spindle blank, I have learned several things to reduce/eliminate them.

First, don't apply heavy pressure through the sandpaper onto the spindle blank, just enough pressure to yield sanding dust.
Second, after each grit with the lathe running, reduce the speed to zero and hand sand the length of the spindle blank, against the sanding scratches around the diameter.
Third, don't skip too many grits. I've found it seldom necessary to use the next grit (80 then 100, 100 then 120, . . .) A suggestion I've often read is not to jump more than 150% of the current grit (80 then 120, 120 then 180, 180 then 240, . . . or 100 then 150, 150 then 220, . . .).
If sanding scratches are still pestering when sanding completed, after sanding with the next grit in a sequence reduce the speed to zero and direct a "raking" penlight light along the length of the sanded area to highlight scratches as shadows.

 

[Richard Coers]

I don’t consider those as swirls. You get swirls off a random orbit sander when you don’t get rid of the swirls from the last course grit. To get rid of rings from the course grit, you shut the lathe off and sand with the grain with a thick felt or cork backed sanding block. Another help is to dampen a rag and wipe down the wood with the lathe shut off. This swells up the scratches and fuzz, and makes it easier to sand off when the wood dries.

 

[hughie]

Yup too much pressure with initial coarse sand paper, the quickest way is as Richard has mentioned or else you laboriously go down through the grits.

 

[Kevin Jenness]

Use better light. Reduce the ambient light level and use a raking light from one or both ends of the lathe across the work to make the sanding scratches more visible. Then work your way through the grits, making sure each one eliminates the previous grit's scratches. Alternating rotary power sanding, hand sanding with the lathe on and/or hand sanding with the grain is a good way to distinguish the marks from successive grits.

 

[Gord Cameron]

Some tips to add to those above...

It appears from those scratches that when you were hand sanding with a coarse grit, you might have held the sandpaper in one place (and probably pressed harder than you needed to). When you are hand sanding, make sure the lathe is at a relatively slow speed (maybe 300-400 rpm) and move the sandpaper quickly back and forth (parallel with the lathe bed) so that the wood is contacted by a different part of the sandpaper (and thus different abrasive particles) each time it passes the sandpaper. I find that this matters most with the coarser grits, but helps on all grits.

Also, you could try spending more time on the next-finer grit until you can confirm that the rings from the coarser grit have been sanded away.

The judicious use of an inertial or rotary sander reduces the sort of ring pattern you get when hand sanding with coarse grits.

 

[Chris Lawrence]

I sand with 3x readers and after sanding a grit with the lathe running I sand across those scratches with the lathe off till there gone. That way I know I got all the previous grit scratches out. Nothing worse then getting down to 320 grit and seeing a 100 grit scratch still there.

 

[Tim Hunter]

‘looks more like burnishing marks from turning.

Tim

 

[Webb Willmott]

I’m going to rechuck and lightly touch the surface to start with a new surface to sand. It does look like I was way too heavy handed with the course grit trying to get the end grain smooth.