Forming chisel side bevels.

[D_W]

I think my real issue is lacking the discretion to stop using the files before they're clapped out. Infills aren't the only thing I use them on, but they certainly get used the hardest there. For hours, and they get hot.

But, I like the aesthetic of planes without machine tool limitations (until you get into rarefied machining like Karl or others - i'll never get to that, it's too much to learn).

Boggs here charges somewhere around $3-$4 for resharpening. I'm tempted to send some real beaters to them to see how they turn out. Otherwise, as you say, most people counting them as consumables in a budget just go for the easy way (buy new), and new vs. acid treated (from my experience with phosphoric - which is really cheap here) creates a fairly significant time difference. 4 hours of filing may become 6.

 

[ED65]

I think my real issue is lacking the discretion to stop using the files before they're clapped out. Infills aren't the only thing I use them on, but they certainly get used the hardest there. For hours, and they get hot.

Yes if the intent is to try to resharpen a file (regardless of the method employed) then it's important not to use it past a certain stage. It'll presumably be something like the recognition point that sandpaper should be retired, a "Yeah it still cuts but nothing like it did when I started..." kind of thing.

I don't know that this applies equally to files but there's likely a sliding slope with heating, where wear increases markedly. So barring some efficient means to cool the file having a second one of the same type to tag in might prove useful.

Boggs here charges somewhere around $3-$4 for resharpening. I'm tempted to send some real beaters to them to see how they turn out.

IIRC, from posts on Practical Machinist or Blade Forums most likely, they are upfront about not starting the process on a file they identify has gone beyond the point of salvage.

 

[D_W]

I usually buy mill files and body files in 5s or 6s because of that very thing - to not fight one that's going around the bend. If they were $20 each instead of $5 or $6, though, I might not buy so many so fast.

This process may still be useful to me for swiss barrette files and other expensive files that don't do a lot of heavy work, but that I wouldn't like to rebuy at $25 each. Some of mine are on the bubble after 8 or so metal planes.

 

[--Tom--]

Slight derail, but any links to more reading on resharpening files? Is it just a case of suspending in acid for a period of time?
Cheer, Tom

 

[D_W]

Yes, but the time period depends on the acid strength.

If you use lant, it can be indefinite.

 

[AES]

Just to add some "lack of clarity", personally I've never tried it. Only electro de-rusting for a few of my Dad's oldest (worked fine).

As per my write up on files & filing a while ago, as an apprentice I was told that for all practical purposes, re-sharpening files is not really possible. So I'm reading all this with great interest (you learn something new every day!). Thanks chaps

 

[ED65]

Is it just a case of suspending in acid for a period of time?

Basically yes, with soak time dependant on acid strength and concentration.

As to the process, I learned almost everything I know about this from a friend who'd picked up all the important bits online, so the info is out there somewhere. There'll be multiple mentions of this on any long-standing metalworking forum I'm sure. The process is at heart very simple and can be boiled down to just a few bullet points, but there are finer details naturally. If you'd like to start a thread on it memzey might post to it and I'll add my process. I just did most of the files in a large job lot so I got to compare results across a wide range of files, and a couple of rasps.

 

[custard]

As per my write up on files & filing a while ago, as an apprentice I was told that for all practical purposes, re-sharpening files is not really possible. So I'm reading all this with great interest (you learn something new every day!). Thanks chaps

I have heard from old cabinetmakers that, to get an extra bit of use from a worn out file or rasp, you leave the tool overnight in wet grass to get a light coating of rust, and then you either de-rust it or just use the tool as is.

I can see how in desperation that might win you a tiny bit of additional utility, but I'm sceptical that it delivers much real or enduring benefit. As far as I'm concerned, when a file's worn out then it's worn out. But if someone can post a well structured WIP to the contrary then I'd be open to changing my mind.

 

[AES]

@ custard (& all): QUOTE: I have heard from old cabinetmakers that, to get an extra bit of use from a worn out file or rasp, you leave the tool overnight in wet grass to get a light coating of rust, and then you either de-rust it or just use the tool as is. UNQUOTE:

I hadn't heard that one before either, interesting. I guess (purely guess mind you) that a light layer of rust builds up and when you remove that (which you would, even just by using it next morning) you not only remove the rust but also the little bits of "curl overs" on each tooth, which at the start anyway, is what normally makes a file blunt. Interesting, as said.

I would only add to that that IMO anyway, you MUST store (and use) files so that they don't "clang together". That will break off (relatively large) chunks of teeth, especially at the edge of the file. Embarrassing, but DAMHIKT please.

But personally I am very interested in this and if memzey et all fancy a post/s explaining the method/s in detail I for one would be very interested. Aside: I was shocked the other day in the local decent tools shop to see how much an ordinary, bog standard 8 or 10 inch file of decent quality (Nicholson or Oberg, I can't remember) costs these days. Over 30 francs each (that's over 20 quid equivalent)!

 

[DTR]

I have heard from old cabinetmakers that, to get an extra bit of use from a worn out file or rasp, you leave the tool overnight in wet grass to get a light coating of rust, and then you either de-rust it or just use the tool as is.

I've read the same somewhere, and I think I've mentioned it on here before. If I can remember where I saw it, I'll post it up.

 

[memzey]

I’d be happy to post up my process for re-honing files. I just did a batch last week so don’t have any blunt ones at the moment but if I make it to a car boot this weekend I’ll pick up a few more (there are always loads of finer files but few mill or turnip grades for some reason) and post a proper wip with photos and some tests. It’s not hard really (seeing as even I can do it (homer)) but I can see how a step by step might be useful to someone who hasn’t done it before.

 

[D_W]

As per my write up on files & filing a while ago, as an apprentice I was told that for all practical purposes, re-sharpening files is not really possible. So I'm reading all this with great interest (you learn something new every day!). Thanks chaps

Thousands or millions of craftsmen peeing in jars for centuries would suggest otherwise!! From the point of view of a master having you work in a business setting where you're getting paid an hourly rate, it's probably true that it's not economically advantageous.

For an el-cheapo working in his or her basement squeezing pennies and not counting hours, there's at least some merit to it, especially if some of the filing isn't heavy removal steel filing.

(my "wood files" are all worn out double cut metal files - some I bought used with that intention because they are the right size and shape with teeth that are just dulled on the ends. they cut about as fast as a fine rasp, even with worn teeth, and aren't catchy - much cheaper to buy than a rasp with a wider range of shapes and sizes, too...and they still work well on brass, even if they don't bite well on steel). A rasp seller in the US turned me on to that years ago - scouting bigger toothed double cut files to replace raps so as not to get into the foolishness of buying $1,000 worth of hand cut rasps to make a few handles or table legs.

re: the liquid honing, this is the place most people in the US use.
http://www.boggstool.com/page5.html

I haven't used them yet, but will. they claim to test files and mark those with teeth too short to come back a gain, about $2.00 a file average (according to them, a process in use for over 100 years).

The people who use these guys (another woodworking forum) say that the files are better/faster/sharper than they were new after the first sharpen.

 

[AES]

Thanks D-W. Very interesting, and your link now saved. Who knows?

 

[D_W]

(peeing in jars was a bit of an oversimplification - use of lant is more accurate. I did notice when someone brought this up years ago that most of the information about lant - and its use in files, beer, bread, collection for widespread ailment, etc - seemed to have an English origin. I'm satisfied to use commercial acids at this point, if not for any other reason except that they must be a lot faster than aged urine).

While everyone likes to bring up lant once it's a known topic, I don't know anyone (including me) who has ever actually attempted it. I understand that through the aging process, it loses its volatility, but I can't really get past it or in good conscience even try it and then have someone else coming to my shop grabbing all over my files. Too inconsiderate to them.

Phosphoric etch is about $12 a gallon here, anyway. So long as you don't spill it on concrete (which is what the gallons are intended for in the first place - concrete etching). Very useful even for basic things like finding a small chip on the corner of a car panel and neutralizing the surface under the chip before touching up the paint.

 

[memzey]

Bought some good quality files that had seen better times at the boot fair this Sunday (please excuse the snazzy footwear):

From the right there is a medium grade half round Roebuck from Sweden, a coarse Oberg square, a coarse 12” Heller Nucut, a fine 8” Stubs half round and finally, to the extreme left, a very fine 6” something from Sheffield.

I don’t have the time to test and treat them tonight as I need to make some more progress on my little girl’s slime box but I hope to be able to write up something by the end of the week.

In the meantime another file related question from me I’m afraid: does anyone know what this pattern is for:

The are US made Nicholsons and the only grade identifiers are the words “FLAT STANDARD”. Anybody know?

 

[D_W]

Milled tooth files (like those) are used, usually for wood, plastic, non-ferrous metals and auto body work.

They will work on mild steel if you don't mind ruining them. If they're dull, they can also be water honed - probably a better candidate even than a standard file because they have so much relief.

 

[AES]

Oooooh, they look nice! +1 for the description above. The one on the L may be a bit worn, but the one on the R looks almost band new/unused. Good find, n good brand too.

The LH one could do with a good "doing over" with a scratch card and perhaps a bit of brass sheet to clear the teeth. Sorry, never heard of water honing, I bow to superior knowledge.

 

[D_W]

liquid honing was probably what I should've said. I don't have any superior knowledge! I believe it's just blasting the files in an appropriate way with a liquid that has abrasive in it, taking an even layer off which results in rounded tooth edges becoming a point - without acid-related embrittlement or heat (and it's cheap).

 

[memzey]

So are you saying that these aren’t good candidates for acid honing then David?

 

[D_W]

Not sure. I haven't acid honed mine, and I've only acid honed files with phosphoric. They sort of had a "dead cat bounce" with phosphoric - a little initial sharpness resurgence, but without the durability of the original file teeth.

That said, milled teeth file are much more "a little bit of air and a whole lot of space", so they work well even with a little bit of wear, the same as a large tooth rip saw will still bite nicely even when it's a little dull.

First thing I'd do after scrubbing/wire brushing them off with a good legitimate cleaner is use them as is and see how they work. I never used milled tooth files with any frequency until I started *planing* mild steel on infill planes to flatten it (something that is far to slow to do lapping by hand on fresh abrasive). Files like that are common here in nicholson or vixen brand, the kind of thing you run across from time to time when you're not looking for it, but never when you are, so I've picked them up when they're a dollar here or there.

For use on wood, nicholson super shear files are much better, but they are much harder to find used and cheap. And for those into little factoids, the 12" super shear is always sharper than the 10". I thought that was a joke once when George Wilson told me to get one of each, but the bigger would be sharper than the smaller. I guess cooper's tooling never changes, because they made them that way decades ago, and the last ones that I got (US made) were still the same. The big one brand new would take skin off your fingers if you weren't careful.

Point with them is more, if you ever see a super shear in the wild, buy first and ask questions later - they leave a waxy planed looking surface whereas the milled tooth files of the vixen type (like yours) can be a bit more trick to learn. Still useful, though.