?? about files...

[Bill White]

Seem that I remember as a kid, (640 yrs. ago) I heard about being able to "soak" files in an acid bath to sharpen them. Am I having a senior moment, or do any others know about this?
Bill

[Robert Rozaieski]

http://www.sawmillcreek.org/showthread.php?t=69170&highlight=boggs

[Mike K Wenzloff]

Seem that I remember as a kid, (640 yrs. ago) I heard about being able to "soak" files in an acid bath to sharpen them. Am I having a senior moment, or do any others know about this?
Bill
We use citric acid. Keep them clean, fairly strong solution (I use a palm full in a gallon jug, but add to it now and again so I don't really know how strong it is) for over night every week. But we use the heck out of rasps and files.

Clean the files really well. They will develop a black gunk after a while, rinse that off once or twice during the soak. If there is metal or wood stuck in the teeth after cleaning, make sure to use the file card on them when you clean them off.

After the first time or two you'll get a better feel for how long to soak them and how much to clean them during the process.

Certain rasps like the Aurious are case-hardened. Too long a soak or soaking too many times will eventually destroy them. But I use citric acid to renew the teeth for X number of times. Nicholson pattern maker rasps are hardened all the way through like files.

Take care, Mike

[Brian Hale]

What is this Citric Acid and where can i get it?

TIA!

Brian :)

[Marcus Ward]

Citric acid is an acid found in citrus fruits. You can get it at most hombrew shops or at www.morebeer.com. I use a pound in 3 gallons which is about as strong as what Mr. Wenzloff indicated above.

[Nick Clayton]

I get mine from either VWR or Sigma-Aldrich. It works well on restoring planes too.