Alum for broken stud removal

[Walrus]

Just seen this video on YouTube: https://www.youtube.com/watch?v=fqZYgReuywM, using Alum to remove a broken stud. Would this be safe to do on a VW T25 engine? It may not be quick but it *looks* easy...

[Oldiebut goodie]

No reason why not provided you can devise a suitable containment for the solution around the offending steel stud/bolt. Saves wrecking the threads in a valuable case. I am surprised that it isn't used more rather than the heat/welding etc techniques.

[itchyfeet]

Thanks, will be trying this

Where would you buy Alum?

[Walrus]

Health food shops apparently! or Amazon/fleabay sell it for ~£5 for half a kilo.

[itchyfeet]

maybe Asian shops too, Fatakdi powder

[multisi]

Interesting and funny - keep yer dick in a vice

[itchyfeet]

same stuff?

Aluminium Sulphate 17% Iron free Al2O3  in sulphate form.

http://www.ebay.co.uk/itm/500g-of-ALUMI ... 1123026367" onclick="window.open(this.href);return false;

[Oldiebut goodie]

I think that it is the potassium alum that is generally used. KAl(SO4)2.12H2O may be wrong though.
But then I have read of the ammonium alum having the same effect so it may not matter too much, speed of reaction different?

[itchyfeet]

Looking at Alum page on wikipedia I think its
Aluminium potassium Sulphate
Or Potassium alum
or Fatakdi powder

[Mr Bean]

Well I like the idea as it would appear to be a bit cheaper than Spark erosion and in some cases do able in situ.
I am surprised that I never came across it as a Salvage Scheme (Posh Bodge) when I worked in Aerospace.
CS

[Oldiebut goodie]

I can recollect seeing it mentioned on a Yank forum a long time ago but never gave it much thought. An ideal solution as a solution to those broken head studs that you petrol guys have trouble with. If it saves damaging an expensive crankcase well worth persevering with to get the remains out however long it takes. It seems to be effective with a supersaturated solution.

[Mr Bean]

As if we petrol heads would use anything else
CS