Tip for grinding aluminum
There’s a bunch of things that work well for cutting fluid when cutting aluminum. In a pinch I’ll use WD40, spray pennetrant (PB blaster), or even kerosene, and paraphin wax works well on some bits at some speeds but not others. Some of the better stuff for the application (besides just getting proper cutting fluid from a machine shop supply) is anything with orange oil (D-lemonine) (about the best, a lot of aluminum cutting fluids are just this stuff or that stuff diluted with something, some of the machining boards like Orange Zep which you can buy in the cleaning section of HD…) or brake clean works really well for some applications.
Instead use a flap disk or a sanding disc pad for grinding and just don’t use it for cutting, bandsaw, something with a carbide tipped blade or in a pinch even a good high speed steel blade will work well… pretty much anything that will work well on hardwood will work well with aluminum. BTW, carbide cutting blades in aluminum are one of the few places that I use a lot of paraffin wax as a lubricant since nothing else really will stick to the blade and anything really liquid will make too big a mess with most of these tools.
Brandon
There’s a bunch of things that work well for cutting fluid when cutting aluminum. In a pinch I’ll use WD40, spray pennetrant (PB blaster), or even kerosene, and paraphin wax works well on some bits at some speeds but not others. Some of the better stuff for the application (besides just getting proper cutting fluid from a machine shop supply) is anything with orange oil (D-lemonine) (about the best, a lot of aluminum cutting fluids are just this stuff or that stuff diluted with something, some of the machining boards like Orange Zep which you can buy in the cleaning section of HD…) or brake clean works really well for some applications.
You should NEVER use an abrasive cutting wheel or grinding wheel on aluminum. It will fill the grain, cause it to overheat and expand and then the wheel explodes (which at 11K rpm gets ugly, I know someone that lost 2 fingers doing this).
Instead use a flap disk or a sanding disc pad for grinding and just don’t use it for cutting, bandsaw, something with a carbide tipped blade or in a pinch even a good high speed steel blade will work well… pretty much anything that will work well on hardwood will work well with aluminum. BTW, carbide cutting blades in aluminum are one of the few places that I use a lot of paraffin wax as a lubricant since nothing else really will stick to the blade and anything really liquid will make too big a mess with most of these tools.
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Brandon
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You can also get aluminum-specific grinding wheels at the welding supply house. I use them in my 8 in. bench grinder, and 4 1/2 in. angle grinder. They don't clog like standard wheels and keep cutting. They have a binder that lets the wheel wear faster, and the aluminum that does stick comes off with the abrasives as the wheel wears.

FWIW, if you’re doing this be CAREFUL, that lack of spiral that they cut on these things is because they were designed for a much more stable tool then a die grinder and if the thing bounces and tags your finger or even when it’s spinning down after you shut off it will give you an evil cut, where it would be rather minor with a normal burr.






