I need to cut a bunch of aluminum "L" stock (1"x1") to make brackets to hang skirt material on a bunch of new bathroom counter tops at a local hotel. I'm going to use my compound miter saw and an older blade. I'm curious if this will help sharpen the blade? I'll bring all of my old blades if it works.

 

Sharpen them? No. Be sure to cut slow, maybe flip them over so you are cutting into the back side of the L.

 

Depending on the size of your saw sharpening the blade (if it's carbide tipped) may not be economical. Do not use a dull blade. Use a fresh or sharp blade. A dull blade will tend to gall and make a more ragged cut. Don't worry about the aluminum dulling the blade. A carbide tipped blade can make thousands of cuts before it dulls.

Make sure to securely clamp, support or position your material so it cannot **** or twist during cutting. This is ususally a problem when your stock gets short and you are trying to get just one or two more pieces out of it. Unlike wood if the material shifts during cutting it can be quite nasty and snap teeth off the blade. So, safety glasses at the minimum.

 

None of my blades are that bad, I was just wondering if by passing the blade through metal if it would polish it enough to give it new life. Will probably cut in the orientation of an upside down "V" but I will practice to see what works best. In the past, tiling, I would cut using my wet saw and a diamond blade. I've used the miter to cut aluminum rails inside PVC porch railings, just never to the extent I have to make cuts on this job.

 

You might want to make a backer so there is only a saw cut behind your material, something flat with the backer sticking up for support.

Bud

 

A carbide blade will cut aluminum like butter. There will be very little to touch up on the cut. Just wear ear and eye protection.

 

Cutting metal might "polish" but it will not sharpen a blade. It will clean off rosin or sap that may be stuck to your blade but only sharpening will restore a nice sharp cutting face to the carbide teeth.

My manufacturing business does a lot of work with aluminum extrusions and we make thousands of cuts through lots of aluminum and the blades last a really long time. The temper of the aluminum has a big affect though. Almost all common alloys cut well when they have a T6 temper which luckily most do. So, if your stock has any paperwork or a stamp on it and you see T6 you should be good to go.

Some angles and bar sold in home centers are dead soft (no temper). So if the material bends easily or has a dull sound when tapped with a hammer be cautious. Un-tempered (not T6) aluminum will cut easily but can gall and stick to the teeth of the blade. When cutting with a clean blade you'll hear a loud high pitch "singing". Once you've heard that sound you'll be able to hear the pitch change and the tone is not as pure when a tooth gets clogged. You must clear the clogged tooth otherwise it causes more galling, making the situation worse. An ice pick is good for picking the stuck aluminum off the teeth. A constant air blast on the blade teeth can help a bit by improving cooling. Best is to use a mist lubricator and an aluminum cutting/machining fluid like Mistic Myst.