Best files for aluminium, best ways to clean them and avoid clogging

There are at least two files made for filing aluminum. One is a Type A file. I do not know what the other type is called. The type A is better for filing small things as the other type has a very course pattern. I would look in McMaster Carr or MSC catalogs. Can not help you on places as I got most of my files at Boeing Surplus years ago.

Dan

They make special files for soft metals. Also, get some chalk and rub it into the teeth. It keeps the aluminum from sticking.

Paul K. Dickman

Paul, I don't know what current thinking is, but when I was writing about it, 40 years ago, a file expert from one of the big file companies told me "chalk for steel and bronze, chalk or oil for soft brass, and oil for aluminum."

The reason NOT to use oil on hard metals it that it can cause the file to skate, which will quickly ruin it.

I use oil for aluminum. Otherwise, chalk.

Thanks for the tips. I've ordered a file card for starters, and four different files - first cut, dreadnaught, bastard, millenicut. Getting myself ready!

The best method of cleaning a file I was taught was to use a small piece of brass sheet maybe 1/2" to 3/4" wide and around 18swg - 16swg and long enough to grip, 2" or so, and push it into the teeth at about 45 degrees and push it parallel to the teeth and it will clean the file far better than a file card in my experience. By pushing the brass down on to the teeth it is soft enough to form little teeth which shifts any debris stuck between the teeth.

My favourite file for finishing work is a mill saw file as they seem to give a better finish as they don't have the little nicks along the teeth.

File cards are usually bad for files. This is because the wires are usually hard and will tend to dull the file teeth. A better solution is to keep the file clean in the first place. Using a light oil on the file is good for filing aluminum. And after a few strokes, especially when the file is new and sharp, wipe the file clean on a piece of lint free cloth. Denim works well. Wipe the file in the direction parallel to the teeth. This means that if you were to be standing up and wanted to wipe the file against your jeans and on your thigh the file would be pointed down almost vertically. The file would then be wiped almost horizontally. This wiping action pushes the chips along the length of the grooves and out. When you do get stubborn chips loading up the file use a piece of 1/2 hard brass to push them out of the grooves. This can be done by setting the file on edge on a bench and then a brass rod is pushed along the file grooves toward the bench. The brass will be soft enough to be cut easily by the teeth so that it can reach the bottom of the groove while at the same time hard enough that it will hold its shape a while. When it stops working just file the end of the brass rod flat and start over. Eric

Does this cleaning process work with copper as well as brass?

Copper will work but it won't work as well for as long. 1/2 hard brass, the most common hardness when in rod form, is just the right hardness. Practically any bronze will work as well. Avoid aluminum bronzes. But silicon bronze will be fine. Eric

I've actually gone so far as to scrape each groove with a carbide scriber! ;>) This will form a new sharp cutting edge.

I use the wire side of the file card on safe edged, single cut "hand" files, drawing it parallel to the teeth. Of course on double cut files the wires would drag over the oppositely angled cutting edges.

Just in case it hasn't been mentioned and the poster does not already know...

If you use real aluminum like from McMaster Carr, instead of using soft aluminum like from Lowe's, it won't stick to your cutting tools.

Good point - I'm in the UK but I've worked with soft aluminium and medium hard aluminium and there's quite a difference, even in colour. The stuff I'm working on for this is indeed soft aluminium.

Well ... *I* like 6061-T6 aluminum for most purposes. (I'm not sure what the nearest equivalent would be in Europe or the UK). This aluminum is soft enough to accept roll threading nicely, and roll threading does not generate chips the way normal thread cutting taps do, so for threading the end to screw onto the razor (assuming that I'm picturing the right sort of razor), it would be easier to use. (I lube the roll threading tap with Molybdenum DiSulfide, and for through holes in aluminum I usually use spiral point thread cutting taps and WD-40 for cutting lube.)

Enjoy, DoN.