thunder550

iTrader: (70)

If anyone is grinding aluminum and having issues with the soft metal clogging up your bit, get a spray bottle and fill it with water, then give the bit a shot of water every few seconds. Keeps the metal from getting hot enough that it gets soft and clogs up the bit. Worked like a charm for me when I enlarged the intake hole on my Radix.

ROCNDAV

iTrader: (100)

Never tried the water but WD-40 and wax also work.

MrDude_1

iTrader: (4)

when my right angle grinder starts to clog with alum, i just grind a piece of steel real fast, and it all flys off.... probly doenst work for bits, but works great for big grinding wheels.

cbrich

If you are just grinding try a flap disc, they work well for me.

Silverback

Water isn’t that great an idea… you can get shocked if you’re using an electric grinder, and it will cause steel collets and other bits and pieces to rust.

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.

xfactor_pitbulls

iTrader: (16)

Agreed, when porting or grinding wax stick, or WD40 are both good tools. The wax is meant for burs that have a tighter cut, like a typical master cut. WD40 burns off alittle fast and you have to respray fairly often to keep from loading. A wider cut like the aluma, or any other aggressive works well with WD40. You can also use a light weight oil, that works best, but obviously makes the most mess. Air tool oil is what I use when doing alot of stock removal on port work, you can just get a small pool going on work your bur in and out of it.

Brandon

Silverback

Good point... I've had better luck with wax on steel and anyplace you'd use a finer burr, and much better luck with WD40 on something like a coarse cut, single cut aluminum burr. In that kind of application the first couple of times it seems like the WD40 just disappears right away, but after spraying it down a few times suddenly you find that you can grind for like 20 min or more without re spraying it.

xfactor_pitbulls

iTrader: (16)

Maybe on steel you could last that long, but it isnt good for your bur. That is how you get them hot and burn off the sharp edges. No matter what, you end up having to spray down fine cut burs about once a minute to keep from loading and its good to hot the wide cut every few minutes. The wd40 really helps to cool them down at intervals, and keep an edge longer.

Brandon

CTSmechanic

iTrader: (2)

Flap disc or 3 inch ro-loc wheels...what I have always used nothing pisses me of more than when some idiot fills a grinding wheel up with alum..

MikeGyver

iTrader: (5)

I use a 1/4 in. shaft router bit in my die grinder. 3/8 in. half round profile, carbide tipped, 2 flutes. It is just like carving wood. It snows aluminum flakes all over me when I use it.
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.

smoknta

For those of you that dont know, they make special grinding wheels just for aluminum. If you are using one for on aluminum that is specified for steel, it will clog. They make different ones for SS, Aluminum, and steel.

Silverback

Heh, I do that all the time, as long as you have some steady hands it works great… I just used a ¼” straight cutting bit as an end mill, and previous to that I used a half round like you’re talking about at a friends house to blend together an opel cadet intake manifold with a flange for a slant six 1bbl carb (yea, weird project) when he brought up “yea, killer job maiting the two together, but how are you going to match the bore shapes, I don’t have any burrs…” “got any router bits?”

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.