Things were going great right up until ...

[mrcodewiz]

Is this end mill salveagable?

[Geof]

Sure (probably), just use a bit of aluminum rod as a punch to knock the wadded up chips out of the flute.

And use coolant/lubricant next time. If you do not have a coolant system just brushing coolant on the workpiece can work quite well.

[mrcodewiz]

I have a mister - apparently I wasn't misting quite enough.

[tikka308]

Were you milling aluminum? Looks like a high helix end mill... (which should be the right tool....)

[Geof]

Originally Posted by tikka308 Were you milling aluminum? Looks like a high helix end mill... (which should be the right tool....)

An acceptable tool. If you have the spindle speed available to compensate for the fewer cutting edges two flute cutters are better because there is more space for chips in the flutes. Also you can get carbide cutters with a higher angle helix than that and this also helps, but nothing can help better than plenty of cutting fluid of the correct type.

[mrcodewiz]

Yeah, it was 6061 doing a profile (read slots). I am using a Nogan mister with Kool-Mist mixed about double what they recommend (double the coolant). Before I installed the mister, I would just stand there with a can of WD40 and occasionally spray the work - I honestly think it had better cooling and produced a better finish than the Kool-Mist. is there anything else I could put in the mister that works better? I kind of wish that I had just gone directly to flood cooling now.

-Kevin

[lerman]

The question is, "What attacks aluminum but not steel?"

Just get some lye and dissolve it in water. Then soak the mill in it until all the aluminum is etched away. It may take a day; but it works great.

Ken

[Matt@RFR]

Originally Posted by lerman Just get some lye and dissolve it in water. Then soak the mill in it until all the aluminum is etched away. It may take a day; but it works great.

Or if you don't want to wait forever, just use a small flat blade screw driver and carefully pry the melted aluminum out of the gullet of the endmill. With caution you can do it without ever touching the cutting edges with either the screw driver OR your fingers. I don't even take the tool out of the spindle most of the time. Time is money and all that...

And mrcodewiz, that's nothing. You know when you've screwed up when half the endmill is in the spindle and the other half is a permanent part of your project. Particularly fun with a 3/4" solid carbide endmill.

[ImanCarrot]

Lye= Sodium Hydroxide (NaOH) in case you didn't know and it will disolve aluminium.

Be careful with it, it'll disolve your skin too. And wear eye splash protection.

[mrcodewiz]

Thanks for the help! I managed to knock it out with a piece of aluminum rod. I don't think I messed up the edge but I'll give it a shot and see.

[Geof]

Originally Posted by mrcodewiz Thanks for the help! I managed to knock it out with a piece of aluminum rod. I don't think I messed up the edge but I'll give it a shot and see.

So everything after the second post was redundant?

It looks like a HSS tool so it is highly unlikely you damaged the edge, with carbide it can happen.

[mrcodewiz]

No, not necessarily. I have some other HSS tools (end mills but also lathe bits) that appear to have a small amount of aluminum welded to them (although they still cut fine). I wonder if they could stand a short dip in lye to clean this up or if it even matters?