alum to remove a broken tap from aluminum

[Rudy Formanek]

Years ago I posted a thread where I failed to make alum work as an agent to remove broken taps. Today I stumbled on this info, so it looks like I was wrong. Maybe in the future I will try it again, but someone else will have be the guinea pig until then. Seems like it does stain ort discolor the aluminum. Holding at just below boiling for a couple hours seems to help.

 

[Terry Keeley]

Broken taps suck.

I find starting a center point with with a ball nose end mill then cutting through the middle with a carbide burr works too.

 

[John Beardslee]

Broken taps suck.

I find starting a center point with with a ball nose end mill then cutting through the middle with a carbide burr works too.

My students built a few tap burners using automotive capacitive discharge electronics from Mallory electronic ignition components. We worked out a good deal on cost and bought components direct from them. We used K&S brass tube as the electrodes. 1/8” max O.D. Which with a little dremel work you could burn out a 1/4” tap. Did I have them do one for me? No, I always had access to EDM’s elsewhere. Sure wish I had one of the little ones now. I might try you tube to see if people still build them.

 

[Duke Mordja]

Learned something new for the shop. I could have tried the alum solution a few months ago.

I'm glad mcmaster sells these tap extractors:

https://www.mcmaster.com/tap-removers

worked great and took 30 seconds from time I broke tap to having it removed.

 

[mr_fons]

Years back a member in our district broke a tap in aluminum and used Hydrochloric Acid to remove it.
Let it sit in the acid for a few days and eats steal but not the aluminum.
But BE CAREFUL.