Broken tap removal Alum method

[PJW]

Hi, I am sure I read this on this site but cant find it now, I have broken a 2mm tap in a manifold block and would like to remove it. I if can be desolved with alum it would make me a happy bunny! the manifold is aluminium. first how is it done & where do you get Alum?

[b.lindsey]

Peter, I found it here in the spice aisle at the grocery. I was doing only a small part though so didn't need a lot to make a saturated solution. Others may have sources for larger quantities.

Bill

[PJW]

thanks for that Bill, my piece is only 15mm square X 45mm it has a 2mm plug tap in to a depth of 8mm. What is the method for the use of the alum? is it a strong solution and is heat used?

Peter

[dsquire]

Hi, I am sure I read this on this site but cant find it now, I have broken a 2mm tap in a manifold block and would like to remove it. I if can be desolved with alum it would make me a happy bunny! the manifold is aluminium. first how is it done & where do you get Alum?

Hi PJW

A while back there was this thread.

 http://madmodder.net/index.php/topic,9167.msg100875.html#msg100875

This should give you the info that you need.

Cheers 

Don

[sshire]

Peter
I've had great success with carbon steel taps and alum. No luck with HSS.
Heat greatly accelerates the disintegration. I make a saturated solution and put it on the stovetop at barely a simmer. Every 30 minutes or so, I add water to make up what's lost. Generally a few hours for me.
I've done what Mosey suggested with HSS taps. Carbide end mill barely oversize then plug.

[1dbweldor]

PJW
 If you have access to a tig machine, you may be able to tig weld the tap with 304 stainless wire to above flush and get on it while it's hot with small vise grips . When it cools enough to rock it back and forth without breaking off. Work the tap out.
 Aluminum is one of the easiest metals to get a broken tap out of if you know the trick.
 We used to do this trick on turbine shells with great success.
 I am in Utah, If you want to get the part to me I will get it out for you.

[fumopuc]

Hi, I am sure I read this on this site but cant find it now, I have broken a 2mm tap in a manifold block and would like to remove it. I if can be desolved with alum it would make me a happy bunny! the manifold is aluminium. first how is it done & where do you get Alum?

Hi PJW, I have just recognized that you are in the UK. A couple of weeks ago I have bought my alum at German ebay.
http://www.ebay.de/itm/Alaun-Kalialaun-Kaliumaluminiumsulfat-Kristalle-zuchten-Knete-Hortensien-500-g-/360736777838?pt=Mineralien_Fossilien&hash=item53fd96666e
I have seen that the supplier will also ship to GB by request.

[PJW]

thank you all for the response, and offers, I will try to get Alum locally & iff not I will get some from auction,

Peter

[Kim]

Hi Peter,
You can see my run-in with a broken tap & using Alum to dissolve it here:
http://www.modelenginemaker.com/index.php?topic=3209.45
There are a lot of helpful comments from others here too.

It worked for me.  Hopefully it will work for you too!

Like Bill, I found the alum in the spice section at the supermarket.  I used several cans of it, so be sure to pick up enough!

Good luck,
Kim

[Admiral_dk]

BEWARE - the stuff to make Hortensia flower turn blue is NOT the stuff we can use 

The right stuff has the chemical formula :

KAl(SO₄)₂ = Kalium Aluminium Sulfat = aluminium potassium sulphate.

Hope this helps.

[fumopuc]

BEWARE - the stuff to make Hortensia flower turn blue is NOT the stuff we can use 

The right stuff has the chemical formula :

KAl(SO₄)₂ = Kalium Aluminium Sulfat = aluminium potassium sulphate.

Hope this helps.

Hi Admiral, that was exactly my recommendation.
http://de.m.wikipedia.org/wiki/Aluminiumkaliumsulfat-Dodecahydrat
In my understanding, the same as offered by the ebay shop.

[Admiral_dk]

Hi Achim

I just noticed the part of your link that said "Hortensien" and since the first batch I got also was called Alun and meant to colour hortensia flowers and wasn't the right formula - I'm normally sceptical, but your right about the seller claiming it to be the right formula .... My apology.

Best wishes

Per

[Tennessee Whiskey]

This is a great awakening to how global we are. No good old Southern gal would even think of putting away some nice crispy homemade pickles without being able to put her hands on some alum. It was also used, for shall we say, some very homemade uses in the days of saloons and brothels during the rush of the Great Gold Rush in the land of fruits and nuts. Great stuff apparently.

Whiskey

[b.lindsey]

And you know this how Whiskey??   

Bill

[Dave Otto]

Yes inquiring minds would like to know?