Finishing question

Bart, maybe you burnished the wood with the file and could have used a flat piece of hardwood or shavings. If so, the fibers were laid out nice & flat, but on finishing will likely rise again to fight another day. Please correct me if the piece finished as nicely as after 'filing'.

Turn to Safety, Arch Fortiter

Burnished.

You can do the same with a handful of shavings, extremely fine sandpaper, or a toolrest that wasn't properly tightened and twisted into the rotating bowl.

Maybe your file is sharper than you think. I've used one to smooth certain things before. I don't think it is the same as burnishing.

Pretty close, when you're talking a mill file. As you know, wood is normally cut with rasps - toothed files - to avoid packing the fiber into fine mill marks. Such a file would really be the equivalent of the side of a board, once loaded.

As you don't know files are like a bunch of chisels lined up. And if they take wood away they aren't burnishing and they aren't like the side of a board. I used files to take knots off natural wood canes and they leave the best. I've done and seen it work have you?

OK, have it your way. But a mill file is a shallow bite, and fills up quickly. How about a look with a magnifier next time you're working to see how quickly they clean.

Thanks for the great replies. I'm building a banjo and I'd sanded the barewood neck working my way up to 600. After reading the replies I tried rubbing the neck with a small piece of wood to see what would happen. Holy cow, the whole thing started gleaming like it'd been sprayed with laquer, just totally beautiful! I'm hoping this smoothness will remain once I put the oil finish on it. Thanks again, Bart.

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I didn't want to argue but if they fill up quickly that means there is wood in there and that means they are cutting not burnishing. They do leave a nice glass like finish. I came across it by accident one day after using a file to sharpen some things. I had some small branches that I had cut off on some canes and was out of sand paper so I just thought I'd try a file and see how it would work. Took em down pretty good and didn't need any sandpaper. Couldn't get a better finish any easier than this.

Tim, once they fill, they no longer cut. They cut when they're clean, just like sandpaper. The metal worker keeps tapping to release, or uses a file card (wire brush) to get the material out. I'm sure you've noticed that loaded sandpaper heats and brightens the surface, leaving a background of scratches, at one time or another. I even clean sandpaper with a file card when sanding wet wood.

As the OP was thinking of trying it on a rotating piece, he had virtually no chance of cleaning it. Ditto if the wood is damp.

A mill file is probably closer to 320 than 220 in "grit," and is meant for non-fibrous material like steel. Fibrous material like wood responds best to a self-cleaning rasp. If you keep it clean with a brush, you've got sandpaper on a stick, if you don't keep it clean, you've soon got the stick.

Of course, both Tim & George are correct, but for the bewildered like me:

It's known that two hundred and eighty seven angels can dance an old mill file: two hundred eighty eight on a rasp. Both might cuturnish wood to a better finish than the traditional sandscrape method. Then there are those flat boards and cabinet scrapers, not to mention bundles of reed. Where will it all end? :) HTH!

Turn to Safety, Arch Fortiter

Hi George I guess you'll just have to try it. I have never had a file fill up so it wouldn't cut. That's with dry wood. If a mill file is so close to

320 or 220 why does it give a glasslike finish. It's more like cutting with a chisel than sanding. If there is wood dust on the bench it is still cutting. Just because a mill file is for metal doesn't mean it won't cut wood.

Off course But think of the implication Arch, no more expensive sand/grit sheets, al we have to do now is to find some round files to do the bowls on the inside, you have some?? Have fun and giggles and take care Leo Van Der Loo

Believe me, in over forty years of school and home woodworking, I've grabbed a mill file more than once, even for wood. I've also demonstrated the difference in wood-removing ability between a rasp and a file ("lemme get this bastard over here") many times.

You mentioned "knots," which to me means you're cutting end grain. That's smaller particle size, almost like metal, which is what the file's for, and should clear approximately as metal. As it comes to longer aspect on the grain it either slides and scores or fills. It then becomes a much finer grit - less exposed tooth above packed groove equal to smaller particle size glued to paper. Makes finer scratches if at all. Same thing with the old garnet paper, which was variable grade. You cracked the big pieces, and the remaining smaller came into play, or the much-admired Tormek, where dulling the edges of the big grains with a rock makes them cut effectively finer, because there is less surface difference in particle height. This is good on a Tormek, and bad on any other grinder, where you must continuously freshen the surface to the detriment of its diameter.

The thread police are on us, so before I anger them once again....

Hi George, A silly attempt to lighten up, not meant to be an angry policeman, tho it does come across that way. Sorry. Please continue the dialog. FWIW, I thoroughly enjoy your cogent comments. They keep this ng running.

Turn to Safety, Arch Fortiter

I never said to throw away your sandpaper, I just said it wasn't burnishing it was cutting. I stand by that. End grain or with the grain it doesn't make much difference. I agree that files and sandpaper can get filled with the material sanded or filed but not in this case. If the blemish was gone like he(Bart V) said were did it go? Can you burnish blemishes away? I've never done that have any of you? Somebody out grab a mill file and try to fill it up with wood so it won't cut anymore. I tried to fill one up but my arms got tired.