How do you folks sharpen your files?

[michael langman]

I think that the key to getting the most out of your file is to clean them often, as you are using them.
I have a brush with soft bristles that I use most of the time.
File cards do more harm then good in my opinion.
I never used chalk, but it sounds like it would help greatly filing aluminum.

[george wilson]

regular chalk works fine. Very useful when filing copper,WROUGHT IRON (The real stuff,which is very gummy!!!) ,or any metal that sticks in the teeth.

[Stanley Covington]

All the blacksmiths I know here in Japan anneal their worn out files, cut new teeth, and then heat treat often without tempering, I had Takijiro do this to two of my old files, and they cut better now than when new.

Any decent blacksmith can do this.

[Chris Fournier]

Muriatic acid works well, you'll get it at a box building store. Do this outside away from your shop. Chalk reduces loading of the gullets.

[Jim Koepke]

Any decent blacksmith can do this.

Yes they can, but how much would they charge for their time to do it?

jtk

[Stanley Covington]

Yes they can, but how much would they charge for their time to do it?

jtk

He charged me ¥3000/ file. New ones of lower quality and much softer hardness would have cost more. I had to wait 3 months, though so he could heat them in the same fire as the saws he made for me.

[Pat Barry]

If a file is truly dull it really can't be sharpened, with acid or by other means. It may be that the acid can attack the rust and or built up gunk and dissolve those things away, but thats it. Any actual acid etching of the file will just dull it more. What Stanley described is really not a cost effective process. If you can't clean it up with a card scraper / brass bristle brush then its probably time to chuck it.

[Patrick Chase]

He charged me ¥3000/ file. New ones of lower quality and much softer hardness would have cost more. I had to wait 3 months, though so he could heat them in the same fire as the saws he made for me.

I think we may be talking about very different sorts of "files" here. I think the OP is talking about the sort that cost quite a bit less than $30/Y3000 new.

[Stanley Covington]

If a file is truly dull it really can't be sharpened, with acid or by other means. It may be that the acid can attack the rust and or built up gunk and dissolve those things away, but thats it. Any actual acid etching of the file will just dull it more. What Stanley described is really not a cost effective process. If you can't clean it up with a card scraper / brass bristle brush then its probably time to chuck it.

The files I am talking about are larger handmade ones, with lots of meat, and start around ￥6,000. It would not be cost effective for cheaper files.

There is a trick to using the wide chisel to cut the closely-spaced lines in the annealed file, and not all blacksmiths are good at it. The older guys are more frugal, and take pride in reworking their old tools, like files, and making their own hammers, tongs, and sen from scratch.

However, if you wanted to upgrade a cheap file, so long as it has adequate thickness, it would improve performance.

Stan

[Joe Tilson]

Patrick is correct, I am talking about the files we use for everyday filing. Saw file or flat files.
To think of it, Stan makes a good point. Good files are worth the effort.
6000 yen is quite of money to throw away.
Oh for the days of 365 yen to the dollar!!!
Sorry Stan, You wouldn't able to make a good profit that way.

[dennis davidson]

I sent several old files to Boggs File Service. Very satisfied with the result.