Anyone sharpened a file or rasp?

Re: Anyone sharpened a file or rasp?

Larry Clinton At Frankfort, (Central) Indiana

Barry, I have done it several years ago. First thing is the file must be totally clean, free of any wood or loose metal particles. Then cleaned with a solvent to remove all oil. As i recall, I used battery acid, though I have heard of using many different types of acid from Vinegar (weak acetic acid), pure sulfuric, Muriatic, etc..

I was somewhat successful, although the tools did leave a rougher surface then they did originally. I think the "teeth" were somewhat irregular in height. I may have left them in too long.

I ran into a large group (Kennedy tool box full) of good files and rasps at an estate auction a few years ago so have more than I will ever use now.

I took all the excess files I have and wrapped them in oil soaked cloths and stored them in the box I found them. I just toss one when it becomes dull and get a new one from my box.

Re: Anyone sharpened a file or rasp?

William Duffield

It depends on how strong your acid is. I leave them in acetic acid up to 24 hours, but in something stronger, like hydrochloric or sulfuric acid, a half hour or hour will suffice. Hang them in the acid vertically, with the teeth away from the walls or other obstructions. Since my rasps and files are in various sizes, and I don't like to waste even something as inexpensive as distilled white vinegar, I choose a cheap poly graduated cylinders to suspend the rasp in. They are a lot more convenient than cutting the top out of a water bottle.

https://www.amazon.com/gp/product/B007FZZUF8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Bob Rozaieski has a useful entry on the subject on his Logan Cabinet Shoppe blog. Read the responses as well.

https://logancabinetshoppe.wordpress.com/2010/12/03/quick-tip-7/

File sharpening service *LINK*

JL

Boggs does a decent job. SaveEdge also is reasonable.

https://www.saveedge.com/file-sharpening/

YMMV


Boggs Tool

Re: Anyone sharpened a file or rasp?

John C Lucas

On the metal.working forums they suggest vinegar.

Vinegar is what I use

Ron in Sterling, CT

Hi Barry,

I soak them in vinegar for 12 to 24 hours, depending on condition. I take them out and immediately rinse them with boiling hot water, followed by an immediate drying with a heat gun (hair dryer will also do). They are not as good as new, but a heck of a lot better than before the treatment. My 2 cents.

Ron

They come back better than new

Bill Tindall, E.Tn.

We use Save Edge

I don't see why an acid soak would sharpen a file. By the nature of chemical reactions the points are going to dissolve fastest for that is where the most surface area is. I would like to see photomicrograph evidence of what is happening.

Re: They come back better than new

Henry Higginbotham

I wondered how that could work, too. It sounds similar to electropolishing, which removes the sharpest, most exposed particles of metal until the surface is mirror-smooth.

On the other hand, just a couple of days ago I was ordering something on Microplane's web site and noticed that they claim to use "a chemical process called photo-etching that defines and sharpens the edge of each tooth on the grater."

Interesting. I think I'll leave a browser tab open and come back to it later.

Citric acid

Derek Cohen (in Perth, Australia)

Barry, I have sharpened many files with citric acid. This is available as a small tub of powder in my local supermarket. I mix 3 of the small tubs (about 120gms) in a gallon bucket warm water, and then leave the files there for 24 to 48 hours (test them after 24 hours).

The files need to be rinsed with soapy water,dried with a hair dryer (you cannot use a cloth), and then I rub them down with oil (camellia or 3-in-one) to prevent flash rusting.

This results in a significant improvement if the teeth are not already destroyed.

Regards from Perth

Derek

Re: Anyone sharpened a file or rasp?

Ray - Middletown, IN

In the old days Nicholson sharpened them by sandblasting. It cleaned off the layer of surface rust from being stored in water and a final sharpening before packaging.

Ray

Re: Vinegar is what I use

Brad Patch

My experience is that cheap imported files/rasps do not react well to a Vinegar bath. A vintage USA made file, that's not already destroyed, will usually show significant improvement with Vinegar. There are two grades of vinegar commonly available, food grade and cleaning grade. The cleaning grade has a little higher acid content. Cleaning grade can be found in the detergent isle at the supermarket.