View Full Version : help please, removing alum from burr

08-26-2010, 12:34 PM
i have gunged up both my aluminum die grinder burrs and would like to know the secret for getting the "glued" on swarf from their teeth.

i thought someone mentioned it a while back, something to do with acid. . . .

and i need them to finish a job im sweating over. . .


(for you brits, gunged up is similar to "aaarrrrgggggg" )

08-26-2010, 01:17 PM
I asked that question and someone suggested soaking it in lye. I used the purple Zep cleaner from Home Depot since it's what I had on hand and it worked fine.

Don't know how long it took since I dropped the end mill in a cup of the stuff and forgot about it for a few weeks.

08-26-2010, 01:27 PM
use them to grind on some soft cast iron. the cast iron will push the glued material out if the cutting edges.

edit: next time keep the bit wet with Wd40, the finish will be beter and the chips will not stick.

08-26-2010, 02:08 PM
Make sure you are actualy using aluminum carbide burrs on aluminum, they generaly have fewer teeth with no crosscut and bigger gullets to prevent cloging.

Rich Carlstedt
08-26-2010, 02:13 PM
sodium Hydroxide ( Lye ) will take it off in minutes, especially if at 160 degrees...DANGER...Wear EYE and Body protection.

The Fixer
08-26-2010, 02:35 PM
Muriatic acid available @ your hardware store

08-26-2010, 03:45 PM
Muratic acid doesn't sound right to me as Acids don't work very good on aluminum without a catylist to break down the surface film. I have heard of the use of Lye but have never tried it.

Forrest Addy
08-26-2010, 04:28 PM
Careful there with those harsh chemicals, carbide will etch too. The tungsten carbide powder in the sintered matrix is fairly inert but the cobalt that bonds it is not bullet proof.

I pick the pins out with a scribe. Alum expands about 5x that of carbide. A little heat to, say, 900 degrees will loosen the bond between alum and carbide making the picking easier when it cools. Don't quench, carbide is brittle.

Dr Stan
08-26-2010, 04:29 PM
I've used this for rust removal and have been told it works to sharpen files and to remove aluminum.


08-26-2010, 04:31 PM
thanks, workedgreat. . .

08-26-2010, 04:32 PM
Put some Tap Magic for Aluminum on it and keep going. It will get it off and keep it off. It's the best cutting fluid for any kind of aluminum cutting.

08-26-2010, 05:12 PM
Havent read the rest but the following works;
metal bucket, pint of water add pearl caustic soda til it boils, allow reaction to slow then add some more, add burrs wait 8 hours Al gone
Std practice for Al extrusion dies by the way but the tanks is somewhat bigger

Dr Stan
08-26-2010, 05:21 PM
thanks, workedgreat. . .

Which one?

08-26-2010, 06:26 PM
sorry, the cast iron thing. i suppose it heated the stuff up enuf and in cooling its just poped off.

Dr Stan
08-26-2010, 11:27 PM
sorry, the cast iron thing. i suppose it heated the stuff up enuf and in cooling its just poped off.

Thanks, guess I'll keep that chunk of cast iron.