Having performed this many times I can testify that it does work. Three years ago I made this video where I show the test of a clean, dull, file. Both before and after sharpening. The sharpening process is effective on files that still have teeth. Missing teeth will not be magically created. A file that is dull to the point of skating over a mild steel surface can be sharpened to where it will cut the same mild steel surface. My understanding of the process is that both surfaces of the file tooth are attacked by the acid. At the same time the tip of the tooth is also being attacked. The triangular cross section looses one atom from each face, and one atom from the point. The effect is to make the tooth thinner by the thickness of two atoms while it gets shorter by the thickness of one atom. Then there is the counter argument that it only cleans the teeth. If the teeth of the file are plugged with pinning, metal shavings that get jammed into the teeth from improper use, the acid will react with the pinning, depending on what material the pinning consists of, and eventually remove it. The problem with that comes from the shadowing effect caused by the pinning filling in the gullet of the file tooth. By filling the gullet the pinning prevents the acid from reaching the face of the tooth. The acid acts upon the pinned surfsce as if it were a flat surface and removes one atom at a time from all of the surface it in contact with. The file tooth gets shorter without a reduction in its cross sectional thickness. So why doesn't the file cut as well as it did when it was new? If you leave the file in the acid the teeth are eventually eaten away leaving a, more or less, flat surface. I said earlier that the acid, if used in this manner, will not create teeth. As it is eaten away, the tooths pitch, the distance center to center between the teeth, doesn't change. The acid removes one atom from the bottom of the gullet at the same time it removes one atom from the tip of the tooth. The tooth gets smaller in cross section in a two to one ratio with its reduction in height. Carried to the extreme the tooth disappears. The effect reduces the gullet, the space where the chip collects, between the teeth. The reduced gullet fills quicker. The file pins and stops cutting when the gullets are full, thus causing the file to slide on the pins instead of cutting. So why don't I sharpen drills with acid? Aha! You've got me there. You have found the fatal flaw in my argument. No one sharpens drill bits with acid. Why doesn't anyone sharpen drill bits with acid? Engineers, machinists, and shade tree mechanics should be jumping all over this method. If it worked they might. The problem is that pesky bit of logic that says the acid removes metal from every surface it touches. Drills come in many sizes. All of them sized by their diameter. Reducing their diameter means they cut a smaller hole. Not very effective. The preferred method, which is grinding, is selective. The cutting edges at the point of the drill are sharpened by removing material, much faster than one atom at a time, from the end of the drill in such a way as to reduce the cross section of the edge. Just like the acid does. Short answers: Acid only cleans the file. No. But it really needs to have a clean file to start with in order to work well. It's never as sharp as a new one. Yes. The teeth are shorter and won't hold as much chip load. You can't sharpen drills this way. Yes. Drills aren't files. Files don't need to be dimensionally stable. I hope I've answered your questions. If not you can go to Old Sneelock's Workshop and see me sharpen files and drill bits. If you really want to know exactly how this works you can perform your own hands on testing. Like engineers, interns, and apprentices do every day. When you have finished your capability studies come back with your facts and data and we can have a discussion. Until then, and I'm sure long after, I'll keep using resharpened files. Why? Because they work.
Thanks for asking. The vise on the table with the steel bar is for testing the sharpness of the files. After the first hour I pulled the tricorner files when they cut well. It took about 2 hrs n the acid for the large file since it was much duller than the tricorner files. After it's sharp I only put it in the baking soda for a few seconds until it stops foaming.
A piece of PVC pipe capped on one end makes a good acid vessel. I did it in my shop and for the first time in 30 years everything began to rust. On some other channel or web site I mentioned this technique and some know-it-all swore up and down that the process doesn't work but it does.
Yes you definitely want to do this outside and away from your tools. Sulfuric acid will eat up unprotected steel. That's why I flush the files with baking soda after sharpening them. We can only offer suggestions. if some choose to disagree then they are just missing an opportunity.
Glad it was helpful! I'm trying something that TH-cam recommended. I created a short referencing an older video. It is suppose to draw views for the original video. This has been one thing that YT suggested that actually worked.
I grew up slowly and gained followers based on the idea that I ask everyone to ask any question that they wish. I have been answering the most interesting questions.
You can use acid type toilet bowl cleaner for sharpening files and rotary rasps, it works better because surfactants have been added that will improve wetting and it will clean off any residual organics. It is also easier to find at the store.
That's SHARP (pun intended)! Never even had a clue about being able to sharpen a file. and didn't know you could. THANKS for a really unique video! A-PLUS!
You are the first person I have seen on TH-cam that uses a file properly!!! Most demonstrations show the "expert" dragging the file back across the job with as much gusto as they use on the cutting stroke, I suppose if they had to make their files as a gunsmith does they would have a little more respect for them, and maybe, just might understand how they work. On the strength of just this video I have subscribed! I have no doubt you will receive many comments about "you have just cleaned the file" these will be from the armchair critics that probably never handled a file. Many thanks for posting.
I hate to tell you: In my limited experience people want to file backward! I've seen it many times. Engineering students, even a professor here and there. They'll do the same with a hack saw, too. I used to say that "Don't File Backwards!" would be on my tombstone. A great and very convincing demo for this is to do as we see here- clamp up a chunk of something, using a piece of black paper under the work. I use aluminum and a coarse file. Take a few strokes and it's just snowing aluminum in a very visible way. Filing or sawing backward doesn't produce any chips to speak of.
Hi there,just for the unbelievers,the acid etch works wonders! Just a tip,always use a file for steel and another for brass or non ferrous metals,as a file used for steel will not work correctly on non ferrous metals,and never allow one file to touch another file, keep each file wrapped separately,to avoid damaging their teeth.Then a good set of files will last many years at home.
Seems like most of the junk boxes that I got at auction had a least 2 files in them. After I learned the sharpening trick I cleaned, then sharpened them and now I have a bunch of them wrapped in paper in one of the bench drawers.
Thanks for sharing this information. I wondered how to sharpen small mill files. I sharpen hoof rasps/files using sulfuric acid. Works great and they are sharper than new. I use the acid right out of the jug poured into a capped 2" PVC pipe. It takes exactly 9 hours. I found that I can sharpen them 4 to 5 times before they are nothing more than knife blanks.
Glad it's working for you. A while after making this video I began exploring yhe idea of vinegar for rust removal. The test samples were auger bits so there was a good reason to find a way to submerge them in a smaller amount of liquid. Like you I went with 2" pvc. Probably those 12" long files work like the auger bits I was trying to clean. Haven't sharpened any since this batch either. Must not be doing as much filing as I use to. :-)
Old Sneelock's Workshop Thanks. Just an FYI: I use gun barrel bluing etch on the naked steel to help keep it from rusting. The etch comes in blue, brown and gray. It's a simple wipe on with a mop applicator much like a pvc glue applicator.
Hardnox Using the bluing is a great idea. I still have a bottle of Plum Brown somewhere. I used it when I made my black powder derringer 30 or so years ago. Has It been that long? I tend to hang onto things. :-)
Dwight Stewart in answer to your query: I wondered how that worked myself. I've speculated but never done any microscopic examination. I think that since the acid eats the metal away at a constant rate over the entire surface the acid is removing an atom from each side of the tooth at the same time it is removing one from the edge. That would mean the tooth is getting thin twice as fast as it is getting short. The effect would be to thin and sharpen the tooth. As far as whether I was "clearly pressed down harder" with the sharpened file you are welcome to invest in a force gage and test the theory on your own. Empirical testing data tells me the files are sharper after I have run them through the acid. You are free to believe what you wish.
So far I've tried a couple of experiments with masking the tips pf the teeth with marker and bluing. Unfortunately it "bled" too deep into the teeth to change the etching profile the way I wanted it to. The idea is that the longer you can keep the acid from attacking the tip, the sharper the file would get. I'll try a few more things and get back to you with results. Meanwhile you can try different things yourself.
Candle wax might work. Heat it to just above plastic state and gently stroke the wax over the file backwards. It's sticky and resists acids well. I'd be interested to hear about your results.
It is also eating away at the cutting Edge of the tooth, dulling it further. The file may be cleaner but is not sharper. If this theory were true, we could sharpen knives in Vinegar or other weak acid.... Think about it.
It works quite well. I like apple cider vinegar better than the white. White come at up to 10% concentration, but the apple cider vinegar smells much better than the white. Sulfuric is cheap and I can mix it to the concentration I want. It is also faster than vinegar. 10% sulfuric will work in about an hour or two depending on how bad the file is. Vinegar can take up to 24 hours for the same effect. I'm not that patient. 😁😎
My Vintage Plumb axe must be damn hard cos i tried this with citric acid and it's much the same,gonna buy a new file like i knew i'd have to.But it was worth a try. Same file worked good cross fileing the bevel on really mangled handplane blade. I stayed clear of sulphuric acid having used it at work n it scares the crap outa me.
Grobe out of Switzerland is highly recommended. I haven't bought a new file in 20 years. The last files I purchased were Nicholson. Since then the manufacturing has moved to Mexico and the quality has suffered.
I don't get it. Is the acid cleaning the debris between the teeth or is it actually sharpening blunt teeth? And why not just rinse the acid away with plain water. What difference does the baking soda solution make?
The file needs to be clean before you start etching it with the acid. Dirt masks the surface of the teeth preventing the acid from removing the steel evenly. Using a base neutralizes the acid rather than diluting it. Without the baking soda there will be weak acid in every pore of the files surface. The file will flash rust almost immediately and will continue to rust until the file is gone or neutralized. 😁😎
Hi, a question: can this procedure, which is illustrated in this video, also work for the file that some Victorinox multipurpose files have? Otherwise that kind of files and (especially) the metal saw they have incorporated, how can they be regenerated? Thank you.
It should be removed from the knife before you attempt sharpening it. Plated files will not work as well. The plating will affect the amount of and where the etching the acid is doing will be.
Good advise. That's why I used cheap, clear plastic tumblers. You can see the reaction of the acid on the files bubbling away but even if you dropped one of the glasses it would just bounce.
I use a length of 1 1/2" diameter PVC pipe with a cap welded onto one end and a cleanout adapter welded onto the other. The end with the adapter has a threaded plug. In the plug I drilled a 1/8" vent hole. The cut the length of the pipe to be about an inch longer than my longest file. Works like a charm. I do all my etching outside.
@@OldSneelock Cool! I have been thinking of creating a jig to hold the fish hooks so only the point will be submerged in the acid. I also have a crazy idea of maybe hooking it up to a motorized lead screw controlled by an arduino on a timer and then slowly pulling the fish hook up and out of the acid (Maybe an hour or so) so that the tip is submerged the longest This should be an interesting project. Going to order some sulfuric acid to experiment with. Thanks! - Jeff
+John Nerren I use drain cleaner in this video. It is drain cleaner that has sulfuric acid as the active ingredient. I use a 10% solution of this drain cleaner to tap water. The regular drain cleaners have inhibitors to help prevent them from attacking the pipes. Straight sulfuric (100% acid) actually won't harm iron. Until there is water added to make the sulfuric an electrolyte the sulfuric can be stored in an iron tank. Just be sure to keep the tank lid on. I was the Plant Engineer at one of the United Technologies plants in Coldwater, MI. There was a sulfuric acid tank outside of the anodize operation. When the tank truck driver filled the sulfuric acid tank, he left the top off. It rained that night. By morning the acid ate through the 1/4" thick iron tank, but only at the water line where the rain sat on top of the acid in the tank. Made a real mess. Fortunately we had containment under the tank and it was filled with limestone so the acid was neutralized and none of it got into the ground water. We welded up the tank and kept using it for at least 5 more years until I left for another job. I'm sure someone will ask. Yes you should be careful when opening a drain with this concentrated type of drain cleaner. Be sure that, once the drain is open, you flush the drain with tap water. If you leave the drain filled with this heavy duty drain cleaner it can eat the pipes up. Also don't use battery acid. Battery acid is straight sulfuric. It will eat up your pipes. It is also heavier than water and doesn't mix well with water. It can stay in the bottom of the sink trap. A friend of mine didn't listen and had a real mess in his bathroom after the P Trap on the sink ate through.
At the weekend I visited a local steam rally and picked up 4 nice Sheffield made files amongst other things (plus 2 hacksaw blades, try square, pincers, try square, new caulk gun, part of a Stanley no. 4 plane, all for £3). Here in the UK it is very difficult to get sulfuric acid as it has stopped being sold in big box stores following some horrific attacks on young girls where it was thrown in their faces by some crazy people who felt that they should not be beautiful. Are there any other ways to sharpen files as I have cleaned them with the copper tool and run the file card over them. I saw that you were involved in a discussion on another channel but thought it best to speak here as the other channel did not seem as friendly as yours.
Hi Tony. Sorry I'm slow getting back to you. You don't have to have a really strong concentration of the acid. You don't have to use sulfuric either. The lower the pH the faster the sulfuric or most any of the acids works. I use sulfuric just because it is quick and easy. Common cooking vinegar will work quite well. The only problem I have run into with using lower concentrations of acid is it takes long enough that I forget to check and the acid eats the teeth off the file.
Sneelock, many, many thanks for this. We can certainly get cooking vinegar easily enough. Do not worry about the time as it has given me the opportunity to buff up the Stanley No 4 lever cap and it looks really nice on the plane I bought last year for the princely sum of £2. It is a really good rally which combines a steam event with a beer festival, heaven !. I will let you know how I get on with the files.
Old Sneelock, just a note to say a big thank you for the vinegar tip. I got 3 pints and soaked two files, one from Nicholson of Sheffield and another from Switzerland and it took off the surface rust and they feel sharper. Only about another 25 files to go !.
+John Nerren The iron, that gets eaten away, goes into solution and leaves the carbon behind. You can wipe off the carbon dust right after it comes out of the rinse with a scrub brush, if you want. The color doesn't really matter though.
How would an acid “sharpen” the teeth of a file? I'll give it a try sometime (when an old file is available - mine are all currently new), but I'm highly doubtful. Further, in the “sharp file” segments, you were clearly pressing down harder than the “dull file” segments, which only increases my doubts.
Try it or not as you wish. If you think I was clearly lying about the process then you can simply pass it off as another scam where I was tryijng to cheat you out of your hard earned...... Wait I don't remember asking you for anything? I'm sure I will be just fine if you never do anything more than go away sad.
In the US apple cider vinegar, or any cooking strength vinegar, is 5% acetic acid. Because it is a lower strength level of concentration it will eventually sharpen the file. I'm not that patient.
Very informative, thanks! I would like to offer something I learned in high school metal shop over 50 years ago. Dress your files with a stick of blackboard chalk. This keeps metal filings from building up in your files, but helps them cut even better, I think. If you try it, you will always use this trick.
+Emory LastNameNoLastName Yes it will. In the US apple cider vinegar, or any cooking strength vinegar, is 5% acetic acid. Because it is a lower strength level of concentration it will eventually sharpen the file. I'm not that patient.
OldJesusFreak1958 Muratic or any acid will perform the sharpening. Muratic has a drawback though. Muratic is another name for Hydrochloric Acid. On low carbon steel it doesn't cause a problem but on high carbon steel like springs and files the hydrogen in the acid migrates into the steel and causes Hydrogen Embrittlement. You can look it up, but in a nutshell, the hydrogen atoms lock up the iron/carbon matrix and makes the steel brittle so it cracks. Sulfuric acid doesn't have that problem and is easily obtainable. If you can't find sulfuric drain opener then battery acid will work.
That's a good point you are making Old Sneelock. Hydrogen embrittlement is dangerous when the part is a fastener or spring. Electroplating can also introduce HE into a part. The remedy is to bake the part at around 400 deg F for a certain period of time and the hydrogen precipitated out.
That's what I use, and yes, it works well for my files. Old Sneelock makes a good point below; however, regarding Hydrogen Embrittlement. The solution to that is to bake the part at a low temperature for a given amount of time.
The idea of using old battery acid seems OK but if you try to buy sulfuric acid in New Zealand you will need police clearance - apparently because this acid is a precursor to the manufacture of P
Old Sneelock's Workshop Did you ever get to try Ernie's using the toilet cleaner? Just interested how well it did because as he said, I can get it and not the straight sulfuric. (me)
Thanks for bringing this question up again. I do not recommend using toilet bowl cleaner. A majority of toilet bowl cleaners use hydrochloric acid in strengths from 10% to 23%. Hydrochloric acid can cause a condition that is called hydrogen embrittlement. failure-analysis.info/2010/12/hydrogen-embrittlement-part-3/ With high carbon steels the hardness causes the steel to be less ductile. Hydrogen atoms have properties that cause them to easily penetrate the surface of the steel and become embedded in the steel/carbon matrix. By taking up room in the matrix it causes the steel be even less ductile. The steel will develop surface cracks and checks that will cause the steel to break. I recommend the sulfuric because it does not cause cracking. The sulfuric acid drain opener is available at the big box stores near where I live and plumbing supply houses carry it also.
Old Sneelock's Workshop Thanks Uncle Snee. Like I was told a long time ago to run a torch a little rich and it'd make the edge of the cut a little harder. Hope I wasn't getting packed full of smoke on that one. Your cure would work fine. Maybe somebody will want to give away a jug of sulfuric around here but the most powerful substance here is moonshine. Thanks again, Pal. (me)
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Having performed this many times I can testify that it does work. Three years ago I made this video where I show the test of a clean, dull, file. Both before and after sharpening. The sharpening process is effective on files that still have teeth. Missing teeth will not be magically created. A file that is dull to the point of skating over a mild steel surface can be sharpened to where it will cut the same mild steel surface.
My understanding of the process is that both surfaces of the file tooth are attacked by the acid. At the same time the tip of the tooth is also being attacked. The triangular cross section looses one atom from each face, and one atom from the point. The effect is to make the tooth thinner by the thickness of two atoms while it gets shorter by the thickness of one atom.
Then there is the counter argument that it only cleans the teeth. If the teeth of the file are plugged with pinning, metal shavings that get jammed into the teeth from improper use, the acid will react with the pinning, depending on what material the pinning consists of, and eventually remove it. The problem with that comes from the shadowing effect caused by the pinning filling in the gullet of the file tooth. By filling the gullet the pinning prevents the acid from reaching the face of the tooth. The acid acts upon the pinned surfsce as if it were a flat surface and removes one atom at a time from all of the surface it in contact with. The file tooth gets shorter without a reduction in its cross sectional thickness.
So why doesn't the file cut as well as it did when it was new? If you leave the file in the acid the teeth are eventually eaten away leaving a, more or less, flat surface. I said earlier that the acid, if used in this manner, will not create teeth. As it is eaten away, the tooths pitch, the distance center to center between the teeth, doesn't change. The acid removes one atom from the bottom of the gullet at the same time it removes one atom from the tip of the tooth. The tooth gets smaller in cross section in a two to one ratio with its reduction in height. Carried to the extreme the tooth disappears. The effect reduces the gullet, the space where the chip collects, between the teeth. The reduced gullet fills quicker. The file pins and stops cutting when the gullets are full, thus causing the file to slide on the pins instead of cutting.
So why don't I sharpen drills with acid? Aha! You've got me there. You have found the fatal flaw in my argument. No one sharpens drill bits with acid. Why doesn't anyone sharpen drill bits with acid? Engineers, machinists, and shade tree mechanics should be jumping all over this method. If it worked they might. The problem is that pesky bit of logic that says the acid removes metal from every surface it touches. Drills come in many sizes. All of them sized by their diameter. Reducing their diameter means they cut a smaller hole. Not very effective. The preferred method, which is grinding, is selective. The cutting edges at the point of the drill are sharpened by removing material, much faster than one atom at a time, from the end of the drill in such a way as to reduce the cross section of the edge. Just like the acid does.
Short answers:
Acid only cleans the file. No. But it really needs to have a clean file to start with in order to work well.
It's never as sharp as a new one. Yes. The teeth are shorter and won't hold as much chip load.
You can't sharpen drills this way. Yes. Drills aren't files. Files don't need to be dimensionally stable.
I hope I've answered your questions. If not you can go to Old Sneelock's Workshop and see me sharpen files and drill bits. If you really want to know exactly how this works you can perform your own hands on testing. Like engineers, interns, and apprentices do every day. When you have finished your capability studies come back with your facts and data and we can have a discussion.
Until then, and I'm sure long after, I'll keep using resharpened files. Why? Because they work.
Rory and joey
Thanks. Thoughtful explanation.
Thanks for asking. The vise on the table with the steel bar is for testing the sharpness of the files. After the first hour I pulled the tricorner files when they cut well. It took about 2 hrs n the acid for the large file since it was much duller than the tricorner files. After it's sharp I only put it in the baking soda for a few seconds until it stops foaming.
A piece of PVC pipe capped on one end makes a good acid vessel. I did it in my shop and for the first time in 30 years everything began to rust. On some other channel or web site I mentioned this technique and some know-it-all swore up and down that the process doesn't work but it does.
Yes you definitely want to do this outside and away from your tools. Sulfuric acid will eat up unprotected steel.
That's why I flush the files with baking soda after sharpening them.
We can only offer suggestions. if some choose to disagree then they are just missing an opportunity.
I'd forgotten about this video. I've got a few dull files, too. Thanks for posting and thumbs up.
Glad it was helpful!
I'm trying something that TH-cam recommended. I created a short referencing an older video. It is suppose to draw views for the original video.
This has been one thing that YT suggested that actually worked.
@@OldSneelock Ahh! I've seen Diresta making shorts of some of his older, more interesting vids, and I had wondered if this was why.
You appear to have a better class of commentators on your channel than on the "other" file sharpening channel! Keep up the good work.
I grew up slowly and gained followers based on the idea that I ask everyone to ask any question that they wish. I have been answering the most interesting questions.
You can use acid type toilet bowl cleaner for sharpening files and rotary rasps, it works better because surfactants have been added that will improve wetting and it will clean off any residual organics. It is also easier to find at the store.
people like you, doing videos like this, are awesome! cheers
That's your fist thumbs up from me. No more dull files (or buying new ones just because they are dull) Thanks bud!
Very informative and this will bring life back to a tool most just toss in the trash.
I knew you could sharpen files, I just didn’t know you could do so at home. Interesting video.
It was an experiment that worked. I have been using the method for about 15 years with great success. 😁😎
That's SHARP (pun intended)! Never even had a clue about being able to sharpen a file. and didn't know you could. THANKS for a really unique video! A-PLUS!
You are the first person I have seen on TH-cam that uses a file properly!!! Most demonstrations show the "expert" dragging the file back across the job with as much gusto as they use on the cutting stroke, I suppose if they had to make their files as a gunsmith does they would have a little more respect for them, and maybe, just might understand how they work.
On the strength of just this video I have subscribed! I have no doubt you will receive many comments about "you have just cleaned the file" these will be from the armchair critics that probably never handled a file. Many thanks for posting.
I wrote out the whole process and post it at a moments notice. The Ed Prices of the world don't bother coming back after the second time.
Could't agree more!
I hate to tell you: In my limited experience people want to file backward! I've seen it many times. Engineering students, even a professor here and there. They'll do the same with a hack saw, too. I used to say that "Don't File Backwards!" would be on my tombstone. A great and very convincing demo for this is to do as we see here- clamp up a chunk of something, using a piece of black paper under the work. I use aluminum and a coarse file. Take a few strokes and it's just snowing aluminum in a very visible way. Filing or sawing backward doesn't produce any chips to speak of.
Now that is just cool. I have some files that are gonna get dipped. Thanks for the education.
Hi there,just for the unbelievers,the acid etch works wonders! Just a tip,always use a file for steel and another for brass or non ferrous metals,as a file used for steel will not work correctly on non ferrous metals,and never allow one file to touch another file, keep each file wrapped separately,to avoid damaging their teeth.Then a good set of files will last many years at home.
Seems like most of the junk boxes that I got at auction had a least 2 files in them. After I learned the sharpening trick I cleaned, then sharpened them and now I have a bunch of them wrapped in paper in one of the bench drawers.
Good info Jeremy. I always insulate my files from clanging together.
My pleasure. Thank you for watching. I hope you found something you can use.
Thanks for the tip Ernie. I'll have to try that on the next batch.
Thanks for sharing this information. I wondered how to sharpen small mill files. I sharpen hoof rasps/files using sulfuric acid. Works great and they are sharper than new. I use the acid right out of the jug poured into a capped 2" PVC pipe. It takes exactly 9 hours. I found that I can sharpen them 4 to 5 times before they are nothing more than knife blanks.
Glad it's working for you. A while after making this video I began exploring yhe idea of vinegar for rust removal. The test samples were auger bits so there was a good reason to find a way to submerge them in a smaller amount of liquid. Like you I went with 2" pvc. Probably those 12" long files work like the auger bits I was trying to clean.
Haven't sharpened any since this batch either. Must not be doing as much filing as I use to. :-)
Old Sneelock's Workshop Thanks. Just an FYI: I use gun barrel bluing etch on the naked steel to help keep it from rusting. The etch comes in blue, brown and gray. It's a simple wipe on with a mop applicator much like a pvc glue applicator.
Hardnox Using the bluing is a great idea. I still have a bottle of Plum Brown somewhere. I used it when I made my black powder derringer 30 or so years ago.
Has It been that long? I tend to hang onto things. :-)
Dwight Stewart in answer to your query:
I wondered how that worked myself. I've speculated but never done any microscopic examination. I think that since the acid eats the metal away at a constant rate over the entire surface the acid is removing an atom from each side of the tooth at the same time it is removing one from the edge. That would mean the tooth is getting thin twice as fast as it is getting short. The effect would be to thin and sharpen the tooth.
As far as whether I was "clearly pressed down harder" with the sharpened file you are welcome to invest in a force gage and test the theory on your own. Empirical testing data tells me the files are sharper after I have run them through the acid. You are free to believe what you wish.
So far I've tried a couple of experiments with masking the tips pf the teeth with marker and bluing. Unfortunately it "bled" too deep into the teeth to change the etching profile the way I wanted it to. The idea is that the longer you can keep the acid from attacking the tip, the sharper the file would get. I'll try a few more things and get back to you with results. Meanwhile you can try different things yourself.
Candle wax might work. Heat it to just above plastic state and gently stroke the wax over the file backwards. It's sticky and resists acids well.
I'd be interested to hear about your results.
Old Sneelock's Workshop
Great idea! I'll be sure to add that to my attempts.
It is also eating away at the cutting Edge of the tooth, dulling it further. The file may be cleaner but is not sharper. If this theory were true, we could sharpen knives in Vinegar or other weak acid.... Think about it.
I found it works on files that are slightly dull but doesn't do much for those that are very dull. That's been my experiance
Glad you liked the video.
New sub from the Wranglerstar channel.
Great info, I have several files that need this treatment. Thanks for sharing your knowledge.
Glad I could help.
Thanks, I’ve been pondering this.
Acetic acid (vinegar) is a known rust remover. A very weak acid but it must have some etching effect as well.
It works quite well. I like apple cider vinegar better than the white. White come at up to 10% concentration, but the apple cider vinegar smells much better than the white.
Sulfuric is cheap and I can mix it to the concentration I want. It is also faster than vinegar. 10% sulfuric will work in about an hour or two depending on how bad the file is. Vinegar can take up to 24 hours for the same effect. I'm not that patient. 😁😎
Thank you for video.
Glad you liked it. 😁😎
My Vintage Plumb axe must be damn hard cos i tried this with citric acid and it's much the same,gonna buy a new file like i knew i'd have to.But it was worth a try.
Same file worked good cross fileing the bevel on really mangled handplane blade. I stayed clear of sulphuric acid having used it at work n it scares the crap outa me.
Great tip, thanks
Thanks for watching.
Thanks for the video. Can this also be done to sharpen a farrier's rasp? Thanks.
I was curious who comes to mind when it comes to high end quality files?
Grobe out of Switzerland is highly recommended. I haven't bought a new file in 20 years. The last files I purchased were Nicholson. Since then the manufacturing has moved to Mexico and the quality has suffered.
I don't get it. Is the acid cleaning the debris between the teeth or is it actually sharpening blunt teeth? And why not just rinse the acid away with plain water. What difference does the baking soda solution make?
The file needs to be clean before you start etching it with the acid. Dirt masks the surface of the teeth preventing the acid from removing the steel evenly.
Using a base neutralizes the acid rather than diluting it. Without the baking soda there will be weak acid in every pore of the files surface.
The file will flash rust almost immediately and will continue to rust until the file is gone or neutralized. 😁😎
Hi, a question: can this procedure, which is illustrated in this video, also work for the file that some Victorinox multipurpose files have? Otherwise that kind of files and (especially) the metal saw they have incorporated, how can they be regenerated? Thank you.
It should be removed from the knife before you attempt sharpening it.
Plated files will not work as well. The plating will affect the amount of and where the etching the acid is doing will be.
Nice video. You left the tricorner file in for one hour. How long did you leave the others in? Also how long in the neutralizer solution?
Be sure to use all plastic containers as a tap on the bottom or a drop of the file on or in the glass mayl result in a acidic mess...
Good advise. That's why I used cheap, clear plastic tumblers. You can see the reaction of the acid on the files bubbling away but even if you dropped one of the glasses it would just bounce.
I use a length of 1 1/2" diameter PVC pipe with a cap welded onto one end and a cleanout adapter welded onto the other. The end with the adapter has a threaded plug. In the plug I drilled a 1/8" vent hole. The cut the length of the pipe to be about an inch longer than my longest file. Works like a charm. I do all my etching outside.
Nice! Would this method work for sharpening fish hook points? I think I will try it.
I haven't tried it. If I did I would only put the point in the solution. No reason to reduce the shank size. Let me know how it works. ☺
@@OldSneelock Cool! I have been thinking of creating a jig to hold the fish hooks so only the point will be submerged in the acid. I also have a crazy idea of maybe hooking it up to a motorized lead screw controlled by an arduino on a timer and then slowly pulling the fish hook up and out of the acid (Maybe an hour or so) so that the tip is submerged the longest This should be an interesting project. Going to order some sulfuric acid to experiment with. Thanks! - Jeff
@@jeffd4927 If you did this, it would be great to see the video. Got to be worth a like for just giving this a try.
Thank-you sir
Thanks. I appreciate you sharing my work.
thanks for posting--
If using drain cleaner what would be the ratio of water to cleaner ?
+John Nerren I use drain cleaner in this video. It is drain cleaner that has sulfuric acid as the active ingredient. I use a 10% solution of this drain cleaner to tap water. The regular drain cleaners have inhibitors to help prevent them from attacking the pipes.
Straight sulfuric (100% acid) actually won't harm iron. Until there is water added to make the sulfuric an electrolyte the sulfuric can be stored in an iron tank. Just be sure to keep the tank lid on.
I was the Plant Engineer at one of the United Technologies plants in Coldwater, MI. There was a sulfuric acid tank outside of the anodize operation. When the tank truck driver filled the sulfuric acid tank, he left the top off. It rained that night. By morning the acid ate through the 1/4" thick iron tank, but only at the water line where the rain sat on top of the acid in the tank. Made a real mess. Fortunately we had containment under the tank and it was filled with limestone so the acid was neutralized and none of it got into the ground water.
We welded up the tank and kept using it for at least 5 more years until I left for another job.
I'm sure someone will ask. Yes you should be careful when opening a drain with this concentrated type of drain cleaner. Be sure that, once the drain is open, you flush the drain with tap water. If you leave the drain filled with this heavy duty drain cleaner it can eat the pipes up.
Also don't use battery acid. Battery acid is straight sulfuric. It will eat up your pipes. It is also heavier than water and doesn't mix well with water. It can stay in the bottom of the sink trap. A friend of mine didn't listen and had a real mess in his bathroom after the P Trap on the sink ate through.
+Old Sneelock's Workshop Thanks for the info.
Useful info. Audio quality was mighty sketchy. Try a lapel mike, so you mouth is always the same distance from the mike throughout the video. 👍
Darwin Schierer This was shot on a Nikon point and shoot 5 years ago. Made an upgrade 3 years ago to a Canon 70D with a shotgun mic.
At the weekend I visited a local steam rally and picked up 4 nice Sheffield made files amongst other things (plus 2 hacksaw blades, try square, pincers, try square, new caulk gun, part of a Stanley no. 4 plane, all for £3). Here in the UK it is very difficult to get sulfuric acid as it has stopped being sold in big box stores following some horrific attacks on young girls where it was thrown in their faces by some crazy people who felt that they should not be beautiful. Are there any other ways to sharpen files as I have cleaned them with the copper tool and run the file card over them. I saw that you were involved in a discussion on another channel but thought it best to speak here as the other channel did not seem as friendly as yours.
Hi Tony. Sorry I'm slow getting back to you. You don't have to have a really strong concentration of the acid. You don't have to use sulfuric either. The lower the pH the faster the sulfuric or most any of the acids works. I use sulfuric just because it is quick and easy. Common cooking vinegar will work quite well. The only problem I have run into with using lower concentrations of acid is it takes long enough that I forget to check and the acid eats the teeth off the file.
Sneelock, many, many thanks for this. We can certainly get cooking vinegar easily enough. Do not worry about the time as it has given me the opportunity to buff up the Stanley No 4 lever cap and it looks really nice on the plane I bought last year for the princely sum of £2. It is a really good rally which combines a steam event with a beer festival, heaven !. I will let you know how I get on with the files.
UK Tony High pressure steam and beer. What could go wrong? :-)
UK Tony
Old Sneelock, just a note to say a big thank you for the vinegar tip. I got 3 pints and soaked two files, one from Nicholson of Sheffield and another from Switzerland and it took off the surface rust and they feel sharper. Only about another 25 files to go !.
No moosic? Aaww... I love that country lick.
Tried it and it seems to work but my files are much darker now. Did I do something wrong ?
+John Nerren The iron, that gets eaten away, goes into solution and leaves the carbon behind. You can wipe off the carbon dust right after it comes out of the rinse with a scrub brush, if you want. The color doesn't really matter though.
It doesn't hurt to degrease them before etching. I use muriatic acid and the come out a nice even matte grey.
How would an acid “sharpen” the teeth of a file? I'll give it a try sometime (when an old file is available - mine are all currently new), but I'm highly doubtful. Further, in the “sharp file” segments, you were clearly pressing down harder than the “dull file” segments, which only increases my doubts.
Try it or not as you wish. If you think I was clearly lying about the process then you can simply pass it off as another scam where I was tryijng to cheat you out of your hard earned...... Wait I don't remember asking you for anything?
I'm sure I will be just fine if you never do anything more than go away sad.
Can u use apple cider vinger.
In the US apple cider vinegar, or any cooking strength vinegar, is 5% acetic acid. Because it is a lower strength level of concentration it will eventually sharpen the file. I'm not that patient.
nice tip thanks.
Very informative, thanks! I would like to offer something I learned in high school metal shop over 50 years ago. Dress your files with a stick of blackboard chalk. This keeps metal filings from building up in your files, but helps them cut even better, I think. If you try it, you will always use this trick.
Could vinegar work for this?
+Emory LastNameNoLastName Yes it will. In the US apple cider vinegar, or any cooking strength vinegar, is 5% acetic acid. Because it is a lower strength level of concentration it will eventually sharpen the file. I'm not that patient.
Old Sneelock's Workshop Okay, thanks!
The short answer is....it works !Does create a new file ? No ! It sharpens the dull file!
Got it in one. :-)
Will muratic acid work as well?
OldJesusFreak1958 Muratic or any acid will perform the sharpening. Muratic has a drawback though. Muratic is another name for Hydrochloric Acid. On low carbon steel it doesn't cause a problem but on high carbon steel like springs and files the hydrogen in the acid migrates into the steel and causes Hydrogen Embrittlement. You can look it up, but in a nutshell, the hydrogen atoms lock up the iron/carbon matrix and makes the steel brittle so it cracks. Sulfuric acid doesn't have that problem and is easily obtainable. If you can't find sulfuric drain opener then battery acid will work.
Thank You very much. I'll purchase some today.
That's a good point you are making Old Sneelock. Hydrogen embrittlement is dangerous when the part is a fastener or spring. Electroplating can also introduce HE into a part. The remedy is to bake the part at around 400 deg F for a certain period of time and the hydrogen precipitated out.
That's what I use, and yes, it works well for my files. Old Sneelock makes a good point below; however, regarding Hydrogen Embrittlement. The solution to that is to bake the part at a low temperature for a given amount of time.
The idea of using old battery acid seems OK but if you try to buy sulfuric acid in New Zealand you will need police clearance - apparently because this acid is a precursor to the manufacture of P
Old Sneelock's Workshop Did you ever get to try Ernie's using the toilet cleaner? Just interested how well it did because as he said, I can get it and not the straight sulfuric. (me)
Thanks for bringing this question up again. I do not recommend using toilet bowl cleaner. A majority of toilet bowl cleaners use hydrochloric acid in strengths from 10% to 23%. Hydrochloric acid can cause a condition that is called hydrogen embrittlement. failure-analysis.info/2010/12/hydrogen-embrittlement-part-3/
With high carbon steels the hardness causes the steel to be less ductile. Hydrogen atoms have properties that cause them to easily penetrate the surface of the steel and become embedded in the steel/carbon matrix. By taking up room in the matrix it causes the steel be even less ductile. The steel will develop surface cracks and checks that will cause the steel to break.
I recommend the sulfuric because it does not cause cracking. The sulfuric acid drain opener is available at the big box stores near where I live and plumbing supply houses carry it also.
Old Sneelock's Workshop Thanks Uncle Snee. Like I was told a long time ago to run a torch a little rich and it'd make the edge of the cut a little harder. Hope I wasn't getting packed full of smoke on that one. Your cure would work fine. Maybe somebody will want to give away a jug of sulfuric around here but the most powerful substance here is moonshine. Thanks again, Pal. (me)
Lewie McNeely Vinegar and Citric acid will work too. I'm just not patient enough to wait the day or two that it takes for vinegar.
Is the vineger and citric acid in a fixed measure or do you stand back and pour???
Acid actually dulls the cutting edge of a file tooth and makes them smell like pickles.
Gord Baker If you are using sulfuric to make pickles that explains a lot.
I was referring to Vinegar which is a weak acid. .
Gord Baker Did you watch before commenting? This video is about how to use sulfuric acid based drain cleaner to sharpen a file.
Wrong! Try it.