Removing a broken tap

[va4ngo]

I am unsure if I have ever successfully removed a broken tap from brass but its worth asking the question.

After having posted a topic in " Mistake s, Blunders and Boo Boos" I have actually broken the 2mm tap in brass. The broken is only just above the flat brass face and I am unsure if I can grab it with a tool.

What can I do? the part involved 2 hours work and I am reluctanty to scrap the job. My solution if I cant get it out is to put a false screw in its place and silver solder the job in place.
What are your suggestions?

 

[DavesWimshurst]

Phil,
I did the same thing, broke a 2-56 tap in a bronze part that had several hours work on it. Soaked it in a warm solution of alum from the kitchen spice rack. I just left the jar with the part in a warm place and went to bed. By the next evening the tap remains just crumbled away and the the bronze had only the faintest of color change.
Hope this helps.
Dave

 

[va4ngo]

Hello Dave and thanks for your reply

The Tap is a HSS tap and I am unsure what Alum is as I heve never seen it used here unless under some other name. That sounds like an easy solution.
Please advise of Alum

Regards
Phil

 

[va4ngo]

Further to my last post.

I have already repaired pert of the bilds with super glue in the valve hole.

Is this Alum likely to affect the super glue?

Phil

 

[rake60]

A long soak in Acetone (AKA fingernail polish remover) will dissolve the
Super Glue. Then simmer the brass part in a saturated solution of alum and water.
An electric hot plate on the back porch set at it's lowest heat works well and
it won't make your house smell like a burnt dill pickle.

Rick

 

[va4ngo]

Thanks Rick

I still dont know what Alum is. I am In Australia and perhaps we know it by some other trade name

What is the base ingredient in Alum?

Phil

 

[DavesWimshurst]

Phil,
Just checked my tap was a cheap hardware store tap and sparked like carbon steel. Alum was used as part of some pickling methods, I just Goggled it. Mine came from the grocery store, in the aisle where spices are sold. Don't know if it affects super glue though a long water soak alone may be bad for the joint. It was just a tip I read in an old book and my first test of the method.
Dave

 

[rake60]

Go to the local pharmacy and ask the pharmacist about alum.
In the USA we buy it at the grocery store in the spices section
as a pickling agent. In the UK it is a pharmaceutical aid for the
treatment of bed sores.

Rick

 

[Maryak]

Phil,

As a fellow Ozzie, it's called Alum and is readily available in garden shops and pool stores. In Adelaide before the water filtration plants it was used as a flocculation agent to get rid of the river Murray mud in swimming pools and also to break down soils consisting of reactive clays.

Best Regards
Bob

 

[va4ngo]

Thanks Bob
I'll try Bunnings for Alum, never heard of it and very surprised that it will attack HSS, I'd have thought the brass would disappear before the HSS

Regards
Phil

 

[kellswaterri]

Hi Phil, ''Alum'' is...
Alum is hydrated aluminum potassium sulfate.

This link will take you to another website and show you how I used it...

http://modeleng.proboards20.com/index.
cg...read=429&page=1

This is where I obtained it...

http://www.hswalsh.com/

Hope you get on all right ...
All the best for now,
John.

 

[va4ngo]

Thanks John
I will try the Alum.

By the way I am in Asutralia.

Cheers
Phil

 

[shred]

I used Alum on an HSS drill bit in a block of brass. Took a couple days of sitting in the jar but worked.

 

[ttrikalin]

showing off my ignorance here, but if you heat (boil) the part, the brass part and the hss tap have different expansion coefficients, and the tap might get unstuck and easy to remove by unscrewing -- you say there's a bit of it protruding that you may be able to catch with a tool...

just a thought.

t

 

[va4ngo]

Thanks Shred and Tom
I will try heating first

Cheers
Phil

 

[Steve J]

go to tips and tricks on this forum and look up alum tap removal. a thread exits there. when you are heating the alum and water solution look for bubbles coming off the broken tap. that will indicate that the tap is oxidising. somtimes it will take 8 to 10 hours of heating but it does work with no damage to the part. steve

 

[va4ngo]

Thanks Steve, that has improved the already good info, I checked the thread you suggested and will try that concise method.

 

[4wheels]

Thanks Steve, that has improved the already good info, I checked the thread you suggested and will try that concise method.

Hi Phil,
Please let's know how you get on - sounds an interesting exercise and if it works it will be a great trick to file away for future use.
Cheers,

 

[rog/tn]

;D Well I just robbed my wife's spice rack and getting ready mix my solution of Alum and water to start soaking my brass part with broken drill bit. ??? What is the proper mixture to achieve desired results? ie one table spoon per cup of water??? Thanks for advice
rog

 

[rake60]

A saturated solution is recommended.

RIck