Broken drill bit

[oregonsteam]

I am building the "Little Kathy" steam engine and while drilling with #50 drill to tap 2-56, the drill bit broke off inside the castin. How can I get the end out so I can tap for the screw?

Thanks!!!

 

[Metal Butcher]

I am building the "Little Kathy" steam engine and while drilling with #50 drill to tap 2-56, the drill bit broke off inside the castin. How can I get the end out so I can tap for the screw?

Thanks!!!

I removed a 1/2" of a 4-40 tap with sulfuric acid . It took quite a few days.

I'm sure members will have other recommendations. Like other acids, alum, etc.

You are in luck since bronze is resistant to many corrosives.

Mechanical removal is another option, and then plug and re-drill and tap. This is a little more difficult for the less than experienced.

Oh, and swearing at the broken off piece doesn't work. Trust me.

=MB

 

[bearcar1]

Hello Oregonsteam, A saturated solution of Alum dissolved in water will dissolve any ferrous metals such as drills and taps that have become the prisoners of brass, bronze and aluminum. Use the solution in a Pyrex pan as the liquid vat will eat its way through a steel pan as well. Keep the solution at a simmer on the stove and replenish the water as it cooks off. You can do a search here for 'removing broken tap' or 'broken drill' and get some more info if you so desire. Good luck with you "Kathy" engine.

BC1

 

[Metal Butcher]

Hello Oregonsteam, A saturated solution of Alum dissolved in water will dissolve any ferrous metals such as drills and taps that have become the prisoners of brass, bronze and aluminum. Use the solution in a Pyrex pan as the liquid vat will eat its way through a steel pan as well. Keep the solution at a simmer on the stove and replenish the water as it cooks off. You can do a search here for 'removing broken tap' or 'broken drill' and get some more info if you so desire. Good luck with you "Kathy" engine.

BC1

bearcar1, Is this the stuff to look for?

http://www.idealtruevalue.com/servlet/the-29818/Detail

Or is this spice the right stuff?

http://www.amazon.com/dp/B0000DCWT7/?tag=skimlinks_replacement-20

Thanks, -MB

 

[speakerme]

Hello,

It is my information that the potassium salt is the one typically used, usually grocer variety.

Best Wishes

Chuck

 

[bmuss51]

there has been 3 methods i have used in the past: 1. redrill as mentioned before in a post. 2.if the hole is going to be a thru hole, then mark the exact spot on the other side and carefully drill (sacrifice drill bit) till you meet the broken drill and the slow down the rpm and push. this is about 75% effective but you have to be careful not to break the second drill and if this happens you might be able to take a punch and knock out both. 3. if there is a machine shop close by, take it to them to have it burnt out by a discharge machine which will be about an hours charge.

 

[gilessim]

I had the same problem with a No.50 bit but I could still see the flutes, I used some alum as described above, and with some very tiny circlip pliers, I managed to twist it out counter clockwise, it worked for me, just my 10 cents worth!

Giles

 

[shred]

Man those #50's... I broke one in a bearing block and used the alum to get it out. Took one day and overnight of sitting in the alum solution (mix it so there are still a few crystals in the bottom of the liquid) before it came loose.

 

[bearcar1]

MB, your second link is the correct item for this usage. Alum is used in the pickling of fruits and vegetables so you 'may' find it at a good food market or pharmacy.


BC1

 

[bob ward]

Getting OT here but I remember from a school visit to the water works that alum is also used in the treatment of drinking water. It coagulates the fine suspended particles into clumps which then settle to the bottom of the treatment tank.

 

[Wannabe2]

alum is also used in the treatment of drinking water. It coagulates the fine suspended particles into clumps which then settle to the bottom of the treatment tank.

As Bob has said it's used as a flocking agent (to make water clear) for treating water. I found this out out after having all sorts of troubles trying to locate some here in Aus and is available at places where you buy pool chemicals.
I had broken a 3mm tap off in a piece of aluminium but wasn't having much success using the Alum (Aluminium Sulphate) until I applied a bit of heat. As soon as I did that the tap started bubbling and 3 hours later there was nothing left of the tap except for a black sludge with no damage to the aluminium.

 

[jwsvandr]

Oh, and swearing at the broken off piece doesn't work. Trust me.

=MB

But it feels sooo good and gives you time to contemplate your options