# Removing a broken tap



## va4ngo (Oct 16, 2009)

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?


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## DavesWimshurst (Oct 16, 2009)

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


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## va4ngo (Oct 16, 2009)

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


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## va4ngo (Oct 16, 2009)

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


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## rake60 (Oct 16, 2009)

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


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## va4ngo (Oct 16, 2009)

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


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## DavesWimshurst (Oct 16, 2009)

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


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## rake60 (Oct 16, 2009)

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


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## Maryak (Oct 16, 2009)

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


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## va4ngo (Oct 16, 2009)

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


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## kellswaterri (Oct 16, 2009)

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.


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## va4ngo (Oct 16, 2009)

Thanks John
I will try the Alum.

By the way I am in Asutralia.

Cheers
Phil


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## shred (Oct 16, 2009)

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


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## ttrikalin (Oct 16, 2009)

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


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## va4ngo (Oct 17, 2009)

Thanks Shred and Tom
I will try heating first

Cheers
Phil


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## Steve J (Oct 18, 2009)

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


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## va4ngo (Oct 18, 2009)

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


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## 4wheels (Oct 18, 2009)

Melbourne_Phil  said:
			
		

> 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,


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## rog/tn (Oct 20, 2009)

;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


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## rake60 (Oct 20, 2009)

A saturated solution is recommended.

RIck


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## shred (Oct 20, 2009)

Start with enough water to cover the part. Get the water nice and hot and put in as much Alum as will dissolve, then a little more. Extra doesn't hurt, and some crystals will grow as the water cools down.


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## Deanofid (Oct 20, 2009)

Diymania  said:
			
		

> I wonder if i still have those heatsinks with parts of drill bits and taps or screws stuck in them.
> 
> What could Alum be called in sweden ? ??? What is this Alum stuff normally used for ? Iask becuse it would help me figure out a possible equivalent where i live.



Diymania, look up Alum on Wikipedia and it will tell you the chemical name, if that will help you.
Here in the USA it's used for cooking. We buy it at the grocery store. It's kept in the spice section. You can also get it at a drug store or a from supplier of regent chemicals.


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## 4wheels (Oct 21, 2009)

I always thought it was used in the curing of animal skins! Also gets rid of (human) skin wrinkles but I wouldn't try it - might end up with a shrunken skull.
Cheers,


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## kellswaterri (Oct 21, 2009)

Hi all, here is the recipe for the alum...it was in an other forum I am in...

 Re: REMOVING BROKEN TAP
« Reply #7 on 2/21/06 at 17:09 »  

--------------------------------------------------------------------------------
Hello Folks,
to continue the saga of ''the broken Tap'', after the collective brain picking of this Forum and others, one in particular [the american horological society], the final result was to remove it with the use of ''ALUM'' i/e...aluminium potassium sulphate...this chemical is commonly used in the clock repair trade for removing rusted or broken screws from out of rare or antique clocks or watches when all else fails.
The process is slow but very sure as I have just proved.
During the tapping of a considerable number of 7ba threads, I managed to snap the Tap leaving approximately 3/8'' of broken tap in a blind hole.
The removal of the broken piece involved the use of a large sauce pan, a pyrex bowl, and 'ALUM', the pyrex bowl was filled with boiling water enough to cover the cylinder with broken tap by about 2'' of liquid, 'ALUM' powder was then poured into the bowl of boiling water until no more powder could be absorbed by the water, the bowl of liquid 'ALUM' was then put into the large saucepan which already had boiling water in it and left to simmer at just under boiling point for 15 hours over yesterday and today, that is what I mean by 'slow but sure', the gunmetal casting was not affected in any way and the remains of the broken tap had vanished.
It was amazing to watch the constant stream of tiny little bubbles erupting from hole where the broken bit of tap was being eaten away with the chemical.
For anyone who has never used this process before [like myself] I would heartily endorse it as an excellent ''MODEL ENGINEERS '' tool 

and a little about ''ALUM''

''ALUM'' quite a few of us on occasion have had to use this substance, but how of its History...

1470: Alum (previously known in the Middle East) is discovered in Europe 
for the first time, specifically Tuscany. It was first found between 
1300 and 1310 in Rocca (Syria). The mineral Alum is 
the double sulphate of aluminum and potassium, AlK(SO4)2 + 12 H2O, 
is a common compound of Aluminum, which was not isolated until 
1825 by Hans Christian Oersted (although anticipated and named in 1807 
by Sir Humphrey Davy). Alum comes to be used for dyeing, leathermaking, 
medicine, paper sizing, and fireproofing.


Europe's problem since Roman times had been a chronic imbalance of trade. Bullion drained out of northern Europe into Italy and thence through the Middle East to the Far East, to pay for imports of alum, grain, oil, and wine, and luxury goods like silk and pepper. In exceptional times and places this problem did not apply. For example, the fur and slave trade through Russia that was run by the Vikings and then by the Russians themselves resulted in a flow of silver north of the Black Sea into northern Europe. But this did not last for very long, and did not affect southern Europe very much. Venetian merchants were always reminding their agents in the east to use barter wherever they could, but they were usually required to pay in silver and gold; failing that, in copper, tin, or lead. 

http://www.wovepaper.co.uk/alumessay1.html

Just a few snippets of its history, for those interested the web site gives an excellent review but a little long winded to down load... 
All the best for now,
John.


« Last Edit: 3/27/08 at 9:44 by lancelot » Link


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## rake60 (Oct 21, 2009)

4wheels  said:
			
		

> I always thought it was used in the curing of animal skins! Also gets rid of (human) skin wrinkles but I wouldn't try it - might end up with a shrunken skull.
> Cheers,



I was a licensed taxidermist at the age of 16.
I bought alum by the pound at that time to cure deer hides for mounts.
Every night I had to pull those hides out of the alum baths to work them over
a wooden beam. It was to keep them from hardening of shrinking.
It was a little tough on the hands. A lot of cracked and split skin on the knuckles.

I didn't know at that time alum could serve a better purpose down the road.
I dumped enough of it in the woods behind the house to dissolve hundreds of taps.

Rick


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## 4wheels (Oct 21, 2009)

Thanks Rick,
I'm pleased my brain still works after all these years. I was getting a bit worried reading the reply above yours. Makes me feel young again!
Cheers,


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## va4ngo (Oct 21, 2009)

Well

A Heartfelt thanks to all of you who actively participated in this wonderful animated lesson on Broken tap removal.

I was taken from the taxidermists, then on to chemistry school and in to the deep dark woods.


Thanks again for some wonderful information.

p.s.

I know of a resting place where we can all take our embedded taps into the the dark. dark woods.

Cheers
Phil


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## Wannabe2 (Oct 25, 2009)

Hi Phil,
You can buy the stuff at Bunnings in the pool section. It's called a flocculent and the active ingredient is Aluminium Sulphate. I spent ages trying to track some down here in OZ. Finally went to bunnings and found 1kg for about $15. Chemists were charging $15 for 10grams. I mixed my brew up in an old rice cooker to keep it warm and it took 3 hours to completely dissolve a 3mm tap in aluminium.


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## jihe (Oct 25, 2009)

Diymania  said:
			
		

> What could Alum be called in sweden ? ??? What is this Alum stuff normally used for ?


It's "alun" in Swedish. Ask for it at Apoteket, I think you can buy it there.


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## va4ngo (Nov 7, 2009)

Thanks Wannabee2, Bunnings looks like a good solution. IOften chemicals are known under different names

Regards
Phil


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## va4ngo (Nov 8, 2009)

Removing a broken 2mm tap from a piece of 1/2" x 5/8" x 1 1/2" brass

Here are my observations after having purchased some Flocculent (active constituent:-Aluminium Sulphate) from Bunnings Warehouse Australia in the pool section.

Cost
2Kg refill pack $9.60 from Bunnings Warehouse
100 gram from local pharmacy quoted $16.00 ( equals $192.00 for equivalent amount)

Method
Made up a Saturated solution of approximately 300 millilitres of water 
and placed in to an old Aluminium saucepan, placed on kitchen stove,brought to high heat then reduced to a low heat

After a few minutes, large (2mm) bubbles began coming from the broken tap area.
Used a shiny Stainless steel spoon for stirring the mixture.

At 15 minutes, 
the shiny stainless steel spoon became a dull stainless steel spoon, Wife not happy( could be useful for making a Satin finish) 
The old Aluminium saucepan became a cleaner Aluminium Saucepan. Wife not impressed. ( could be useful for cleaning oxidised Aluminium) Metal stove top can become discoloured if spillages occur. Didn't alert wife to this.

At 30 mins
Small (less than 0.2mm) Bubbles still escaping from broken tap area.
Will give final results when completed

Phil


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## tel (Nov 8, 2009)

> Will give final results when completed



Good Phil, I saw that flocculent at Bunnings and wondered if it would work


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## tmuir (Nov 8, 2009)

Wow, Bunnings is selling something useful that is hard to get elsewhere.
That's got to be a first.
I've not broken a tap yet but I'm sure I will at some point.

I've been thinking about buying one of those bench top ovens with a hob on top of it for curing paint and having a go at jappaning.
This has just given me another reason to get one.


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## Wannabe2 (Nov 8, 2009)

Good one Phil but I think you had better find another heat source while you can still walk. :big: Not worth upsetting SWMBO.
Good price too. That's cheaper than what I saw it going for.
Someone gave me an old rice cooker an I used that. They'd broken the glass lid which is why they had given it to me but I stretched a bit of plastc over the top to cut down on evaporation. I've seen these rice cookers going at Aldi for $19


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## va4ngo (Nov 8, 2009)

at 1 hr and 45 minutes, added more water as some has evaporated.

I can now poke a toothpick in to one of the holes where the tap used to be in the vertical hole.

Note
There are two broken taps in this rectangular piece. One is vertical on the part and the other is horizontal, 75% of the vertical tap has been dissolved, however the horizontal tap is still intact. The vertical tap seems to be more affected by this process and I would now suggest this may be the preffered way to help dissolve the part i/e Place the part in the pot so the broken tap is upright.

Aluminium pot has become somewhat scummy , probably remains of some of the dissolved HSS tap. Pot which is in contact with the solution is verty clean. Wife still not impressed.

At 2 Hrs, the horizontal tap has now begun to bubble. Rearranged the part in the pot so that other broken tap is now sitting vertically.
In order to still have the part covered, I needed to add extra water ( approx extra 300 Ml. Now I suspect that the solution is no longer saturated so may need to add extra Alum and re saturate the solution. ( add extra Alum until it will no longer dissolve)

I am now also thinking that because of the effects on the Aluminium pot and the Stainless steel spoon that perhaps I should not be using these materials for trying to dissolve the part as some of the active ingredients are actually dissolving the parts I dont need to be dissolved. Perhaps a brass pot with a plastic or brass spoon or even better a pyrex pot may speed up the process and use up less Alum.


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## va4ngo (Nov 8, 2009)

Hello Wannabee2
Is the rice cooker of Ceramic material?
I dont have the pot covered

Phil


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## Wannabe2 (Nov 8, 2009)

Melbourne_Phil  said:
			
		

> Hello Wannabee2
> Is the rice cooker of Ceramic material?
> I dont have the pot covered



The cooker I used was one of those teflon coated ones.
I had a bit of blackish ozidisation on my part after I was finished but it cleaned off easily.

Just drape a bit of Gladwrap or clear shopping bag loosely over your pot so it hangs lower in the middle. Poke a couple of small holes in it to help release the pressure. That way when the water evaporates it will drip back into the pot and cut down on your evaporation.


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## shred (Nov 8, 2009)

FWIW, heat is not actually required; it just speeds the process. When I had to get a drill out of a brass block, I made the solution hot, then stuck the part and solution in a covered jam jar and left it there, shaking occasionally, for a couple days and the drill was gone. Lots of Alum crystals formed in the process as the solution cooled but didn't seem to hurt anything.


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## va4ngo (Nov 8, 2009)

Thanks Wannabee2 and Shred both good tips especially as I dont want to dull any more stainless steel spoons.


Left the part overnight on stove top turned off.

Both Taps are now completely dissolved and was able to put a screw in the hole without any further tapping required. I must have been at the bottom of each hole when the taps broke.

Highly Recommend this method of broken tap removal. Am now trying to remove a broken tap from an Alumiinium block from my v-4 Oscillatong cylinder engine from 20 years ago.


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## wm460 (Jan 25, 2010)

Very interesting link, Glad to see that Alum is readily available in Aust.


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