Beginner question/help

[Thomas Wilson80]

Hi All,

I am just in the finishing process of my first hollow form (about 8" x 6") and after putting on some Danish Oil, noticed a band of lighter coloring all around the piece at the widest area. I'm assuming this is from poor sanding technique or tool control issue. I used a drill to sand and was trying to be very careful sanding with light and even pressure. Any suggestions/tips?
Assuming the only way to fix this is to sand off the DO and redo, right?

Thanks,
Tom

413241

[Paul Williams]

It may be just the nature of the grain. At the widest point you are cutting "flat" across the grain. As you move towards either end your cut exposes the cut end grain. The end grain soaks up more finish than the flat grain making it darker. If you don't like the look you could try sealing the grain with shellac as your first finish coat. Several coats on really porous wood. I like the looks of your form. I have done several similar. Mine tend to have a wider, flatter top, if that makes any sense.

[Chris A Lawrence]

Sometimes you can wet sand by hand with 400 grit sand paper and the finish you used to make it disappear. Danish oil is easy to wet sand with since it takes a while to start drying.

[John Hart]

Sanding is an art all to itself...especially with woodturning. This is due to the many grain directions, the curvatures, and the grit of your sandpaper.
Sometimes it's necessary to stop the lathe and do some elbow grease in th pesky spots. Probably not necessary to remove all the DO but get the rough areas worked down. Maybe go to 320 and work against the grain until you have a glassy surface

[Thomas Wilson80]

Sometimes you can wet sand by hand with 400 grit sand paper and the finish you used to make it disappear. Danish oil is easy to wet sand with since it takes a while to start drying.

Interesting idea - what speed do you generally wet sand at?
thanks,
tom

[John K Jordan]

It may be just the nature of the grain. At the widest point you are cutting "flat" across the grain. As you move towards either end your cut exposes the cut end grain. The end grain soaks up more finish than the flat grain making it darker. If you don't like the look you could try sealing the grain with shellac as your first finish coat. Several coats on really porous wood. I like the looks of your form. I have done several similar. Mine tend to have a wider, flatter top, if that makes any sense.

I agree with Paul that it could be in the wood. Without seeing it with my own eyes it's hard to tell but it may very well be the wood itself. As well as the end grain soaking up finish differently, the light can interact differently with side grain (at the "equator") and the end grain (every where else in a form like that, to some degree). If it were a cutting or sanding technique issue, for example what I call "micro" tearout, you should see evidence by examining with a magnifier.

Also, look at the lighter band in a strong "point source" light, a small diameter bulb rather than, say, wide diffuse light from long fluorescent fixtures. In some cases you may see some chatoyance, i.e. the appearance will change as the piece is turned different ways in the light.

The grain in some woods returns light to the eye differently than in others. For example, you might see this effect more in darker woods such as mahogany and less in lighter woods. I've seen the lighter band in turned spheres, eggs, vases, etc.

Of course, it could also be poor cutting and sanding technique! It's easy to tell with your eyes if you know what to look for. Maybe let an experienced local turner take a look.

JKJ

[Chris A Lawrence]

Elbow grease speed. I do all my wet sanding off the lathe. I rarely finish anything on the lathe anymore. For danish oil i have a 5 gallon bucket of home made that i submerge the piece into if it fits in the bucket for an hour to overnight. Then pull it out, let it drip for a little bit followed by wiping off the excess. If i see any spots that the danish oil brought out i wet sand them this makes a slurry that fills in the pores and blends them in.

[Thomas Wilson80]

Thanks everyone for the info and tips.

tom