Special file for aluminum - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 13, 2015, 11:11:06 pm
content: I was a little surprised when I noticed people at work using regular flat bastards for steel with aluminum. Of course the file clogged up instantly and you have to work 5 times harder to make little progress.I asked them "why not just get an aluminum file?"Turns out they never heard of that, so I brought mine in the next day and it was a revelation to them.To be fair, I don't work in a metal shop, we make RF stuff and I guess we just need tools for touch ups and what not, but still, the difference is like night and day.What do you use? You got a nice set to recommend?

author: ataradov
author_rank: Super Contributor
timestamp: December 13, 2015, 11:33:09 pm
content: I know about them, but I don't have a set. So I use steel files and a metal bristle brush to clean them from clogging.

author: v8dave
author_rank: Regular Contributor
timestamp: December 13, 2015, 11:42:09 pm
content: I used to use chalk on a metal file and this reduces the clogging and makes it easier to clean. Handy for the odd times you need to file some aluminium. I learned that technique when I was doing mechanical engineering in my teens. If you can find single cut files, they work good on aluminium too.

author: nctnico
author_rank: Super Contributor
timestamp: December 13, 2015, 11:45:05 pm
content: Never heard of such files but then again the files I have don't tend to clog when using them on aluminium. I did see a metal workshop where they had seperate files for non-ferro metals like brass.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: December 14, 2015, 12:03:14 am
content: I recommend you throw them out when you wear them out. They're files, not family heirlooms.We're in Canada so you can get Nicholson files cheap.(Note I'm a rabid anti-file-snob snob. I use files "both ways" just to annoy others.)

author: ataradov
author_rank: Super Contributor
timestamp: December 14, 2015, 12:21:49 am
content: Quote from: Paul Moir on December 14, 2015, 12:03:14 amIt is not about wear. Steel files will never "wear" when used on aluminum, but they will clog like crazy after just a few strokes and will not cut as well after that without cleaning. Separate files solve this problem.Separating files for ferrous and non-ferrous metals is a completely different story and totally relevant unless you run large scale fabrication shop.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: December 14, 2015, 12:25:56 am
content: Or you can just throw them out and get new ones.

author: ataradov
author_rank: Super Contributor
timestamp: December 14, 2015, 12:26:33 am
content: Quote from: Paul Moir on December 14, 2015, 12:25:56 amAfter each use?

author: Paul Moir
author_rank: Frequent Contributor
timestamp: December 14, 2015, 12:34:46 am
content: No, when they get worn obviously. WD-40 or similar (like chalk above, I have to try that one.) work well enough to keep chips from building up in a regular mill or bastard file, and you need a file card anyway. Just that it's not worth keeping separate files if you do mixed work.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: December 14, 2015, 01:13:23 am
content: oh shit i need one of those

author: Ian.M
author_rank: Super Contributor
timestamp: December 14, 2015, 02:15:16 am
content: Use a brass wire brush first. A file card has hardened steel bristles, and doesn't do the cutting edges any favours even brushing in line with the teeth. If a file is badly pinned with light alloys, warm lye solution will clean it up pretty quick by dissolving the Aluminium or Magnesium. Don't use lye if its pinned with copper alloys. Scrub out any remaining dirt with the line of the teeth, Wash off thoroughly with boiling water, dry in a warm place and wrap in VCI paper as it will now be absolutely grease and oll free so can flash rust if left out in damp polluted air..

author: Tomorokoshi
author_rank: Super Contributor
timestamp: December 14, 2015, 02:56:27 am
content: Welding shops have a paraffin wax kind of thing that you can scrape into the file first that makes it easier to clean the file.

author: calzap
author_rank: Frequent Contributor
timestamp: December 14, 2015, 03:43:44 pm
content: There are also special grinding wheels for aluminum (or aluminium or element 13). They have a rubber base material with silicon carbide grit. Changing wheels on grinders can be a pain though, and one has to do a lot of aluminum work to justify a separate grinder. Regular grinding wheels clog pretty quickly with Al. Frequent dressing works OK, but wears them down pretty fast.Flap type grinders, available in disc, cylinder and wheel forms work pretty well on Al.Mike in California

author: d-smes
author_rank: Regular Contributor
timestamp: December 14, 2015, 05:07:57 pm
content: So what's different about the teeth? Looking at the image athttp://www.amazon.com/Nicholson-Aluminum-American-Pattern-Rectangular/dp/B006P2XB4Eit looks like a rasp style. Please enlighten us!

author: ataradov
author_rank: Super Contributor
timestamp: December 14, 2015, 05:13:30 pm
content: Quote from: d-smes on December 14, 2015, 05:07:57 pmThey are coarser and grooves between the teeth are wider, so filings don't have a place to stay jammed.

author: mikerj
author_rank: Super Contributor
timestamp: December 14, 2015, 10:43:56 pm
content: Quote from: Paul Moir on December 14, 2015, 12:34:46 amYep, I just use WD40 (or it's equivalent) and it works perfectly. A quick brush with a wire brush afterwards and the file is clean. This also leaves a smoother finish on the aluminium being filed.

author: TerraHertz
author_rank: Super Contributor
timestamp: December 15, 2015, 02:02:12 am
content: Nobody has mentioned the *best* way to file aluminum. Just squirt some kerosene on the file first. Suddenly it's like filing butter. The teeth never get clogged, and the workpiece gets an amazingly smooth, shiny surface as you file.I keep a screw-lidded jar half full of kerosene, with a glass syringe in it. Just pull some kero into the syringe, then squirt onto the file. No need to keep buying spray cans, etc. Kerosene is cheap, and you probably already have a drum of it.If you have any files already clogged with aluminum, use a scriber point or something sharp to run along the file grooves to clean out the chunks of aluminum. Then apply kero, and never have to do that again.Edit to add: Kerosene also works wonders when using a power jig saw to cut aluminum sheet and plate. Run a bead of kerosene along the marked cut line before starting. The blade stays clean, and the cut runs much easier. The only consequence is your cut line marking must be a scribe line, as marker pen, pencil etc will be washed away by the kero.

author: KL27x
author_rank: Super Contributor
timestamp: December 15, 2015, 02:06:04 am
content: QuoteI'd throw Nicholson files away, too.

author: robrenz
author_rank: Super Contributor
timestamp: December 15, 2015, 02:20:21 am
content: I have my files re-sharpened up to four times before they get thrown out. The service I use is very reasonable and they are usually sharper than when they were first purchased. Yes, I do a lot of filing.

author: KL27x
author_rank: Super Contributor
timestamp: December 21, 2015, 09:06:37 pm
content: A good file lasts a long time. My favorite is from an estate sale. I can't find any logo on it. It's a relatively fine grit, yet it cuts a lot faster and smoother than any file I have bought new at a hardware store, and it just keeps on trucking. I lucked out, because I wouldn't have known how good it was by looking at in. In fact, I bought two files, and one turned out to be a total bust.QuoteI'm sure there are some newer and more expensive methods for sharpening special/expensive files. One very simple method is putting the file in some phosphoric acid for few hours. You can do that yourself. It works well for a limited number of sharpenings.

author: langwadt
author_rank: Super Contributor
timestamp: December 21, 2015, 09:13:28 pm
content: Quote from: TerraHertz on December 15, 2015, 02:02:12 amI find ethanol works much better and it doesn't leave a mess

author: cs.dk
author_rank: Unknown
timestamp: December 22, 2015, 08:37:34 am
content: Quote from: langwadt on December 21, 2015, 09:13:28 pmI agree, it works really well and everyone has it in their home. Easy to wipe off afterwards, or just a blow with compressed air - and your done.It's also great for drilling and tapping aluminium.

author: krivx
author_rank: Frequent Contributor
timestamp: December 22, 2015, 08:47:23 am
content: Quote from: robrenz on December 15, 2015, 02:20:21 amHow does that work? The sharpening process I mean. A tiny grinding wheel between the teeth?

author: MikeW
author_rank: Regular Contributor
timestamp: December 22, 2015, 08:51:05 am
content: Quote from: robrenz on December 15, 2015, 02:20:21 amAre you trying to escape from prison?

author: FrankenPC
author_rank: Unknown
timestamp: December 22, 2015, 08:52:34 am
content: I wonder if aluminum shrinks significantly more than high carbon steel when dipped in a ice bath? It would be awesome to rig up a ultrasonic ice bath with a mild lubricant to just shake the aluminum bits off.

author: algorhythm
author_rank: Contributor
timestamp: December 22, 2015, 10:49:26 am
content: Yes, aluminum will shrink more. Please rig up a chilled kerosene bath and show us video.If I don't have an aluminum file handy, I usually dust baby powder onto a normal file and just wipe it across my leg every few cuts. The file tends to stay unclogged and cuts fine...

author: Pjotr
author_rank: Frequent Contributor
timestamp: December 22, 2015, 11:17:37 am
content: Quote from: cs.dk on December 22, 2015, 08:37:34 amThat works indeed really good. Point is merely that alu "welds" very easily to the cutting edges of the tools. The same with machining of alu (drilling, turning etc.). Regular household ethanol will "cool" the cut to avoid welding. But be careful, is is not only highly flammable, it is also a pretty good degreaser. Don't be surprised your files, vice etc. are rusty next day.Another very old trick is to chalk your file with school board chalk sticks.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 22, 2015, 11:38:47 am
content: Quote from: calzap on December 14, 2015, 03:43:44 pmIt's not a good idea to use the same grinder for ali. and steel due to the risk of accidental thermiteI don't do much filing, but for other machining, especially step drills, I find that Servisol switch cleaner makes an excellent cutting lubricant. This stuff is fairly similar to WD40

author: calzap
author_rank: Frequent Contributor
timestamp: December 22, 2015, 04:44:33 pm
content: Quote from: mikeselectricstuff on December 22, 2015, 11:38:47 amDanger of a thermite reaction is nil IF you clean-up dust and shavings (aka swarf) after each use. Reminds me of an anecdote in the second of Guy Lautard's Machinist's Bedside Reader series. These books are worth reading just for the anecdotes but also contain a wealth of information and tips on machining.There was a young ME that needed some very large sheaves turned on a lathe, and the closest shop with a large lathe was owned and run by a crusty old machinist. ME gave him the job but commented that he should clean-up the area under the lathe, which was piled with swarf from a variety of metals. Old machinist had a fit and told the ME he had been doing work before the ME was born, so butt out. Sure enough, before the job was completed, a thermite plus magnesium fire ignited and cut the giant lathe in half. Destroyed the sheave that was mounted in it too.Mike in California

author: Chris Jones
author_rank: Regular Contributor
timestamp: December 24, 2015, 06:39:17 am
content: Quote from: Paul Moir on December 14, 2015, 12:25:56 amThat is like saying that you can use masonry drills on wood, and if it doesn't work well you just throw them out and buy new masonry drills to keep drilling the wood.Having recently tried using an aluminium file, after previously struggling to file aluminium with ordinary files that clogged, I know that there is a huge difference even when the files are new and have only been used for a few minutes. The aluminium file is definitely worth having, even if you could get it done eventually with an ordinary file and chalk and/or various waxes and lubricating oils.Chris

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: December 24, 2015, 08:10:40 am
content: This is the best method I've seen for quickly removing said clogging

author: robrenz
author_rank: Super Contributor
timestamp: December 26, 2015, 05:30:14 pm
content: Quote from: krivx on December 22, 2015, 08:47:23 amIt is a wet abrasive blasting process at the right angles

author: robrenz
author_rank: Super Contributor
timestamp: December 26, 2015, 05:45:25 pm
content: Quote from: MikeW on December 22, 2015, 08:51:05 amI make a living as an engineer/machinist. The parts I make all require extensive deburring/chamfering therefore lots of filing.