Weld Penetration Etching... What Do We Use Now???

[zzr1200]

It appears that Nitric Acid is no longer available to the general public unless you apply for a licence, my son is just learning to weld (mma) at college and wants to practice at the weekends, he's also asked me to help him with mag/mig and tig.

Does anybody use (or know of) a substitute that can be purchased, sensibly priced of course.

 

[Bill Edwards]

Products that convert rust seem to work, I think it is phosphoric acid they use.
Battery acid would probably be fine and should be easy to obtain. I think it was sulfuric acid that I used when in college, I don't know the strength but it won't have been anything special.

It might take a little longer when the acid isn't very strong, but I'm sure you won't be in a mad rush and can wait a few minutes!

 

[TechnicAl]

Im told this is stuff works
1 part iodine
2 parts potassium iodide
10 parts water

never used it myself so Ive absolutely no idea how quick/slow it is


I think the Nitric ban is due to our bomb making citizens..........it could be an ingredient

 

[pedrobedro]

Try cheap Cola, it seems to rot everything else on contact so it might etch steel.

 

[hotrodder]

Ammonium persulphate is dirt cheap and is mentioned as an alternative to nital in several AWS and ASM International papers for example http://products.asminternational.org/fach/data/fullDisplay.do?database=faco&record=345&trim=false
10% solution in water

I've not played with ammonium persulphate but have with the usual houshold chemicals (brick acid which is typcially hydrochloric and/or phosphoric in various concentrations) and stuff like battery acid (sulphuric, 33%?) etc and while they all kinda work the results are nowhere near as detailed as with nital

ETA mentioned here too... http://www.struers.co.uk/resources/elements/12/97489/Application Notes Welding English.pdf along with other reagents for various flavours of metal

 

[awemawson]

How much do you need - masses on ebay !

http://www.ebay.co.uk/itm/Nitric-Ac...Equipment_Lab_Supplies_ET&hash=item25747b543a

Perhaps the 'general pubic' doesn't use eBay !!!!!

 

[hotrodder]

Scroll down the listing and after it says blah blah, licences, blah blah go to this .gov site (same as the link in the OP) to read about licensing for home users of explosive precursors and find out how to apply* for one etc it says

Sales to Limited Companies will not be affected, but all companies will be subject to standard routine due diligence checks, including completion of a Declaration of Use. Please note our due diligence checks may result in a slight delay in despatch of your order

and

Please note without provision of a license we will be unable to complete any orders to an individual and will refund and cancel as appropriate

* Appears to be justify your need for the stuff and then pay for a criminal record/background check in exchange for a licence and agreeing to repeat the i'm not a terrorist, honest guv forms every 6 months

 

[Fintray]

Im told this is stuff works
1 part iodine
2 parts potassium iodide
10 parts water

never used it myself so Ive absolutely no idea how quick/slow it is


I think the Nitric ban is due to our bomb making citizens..........it could be an ingredient

Can be used to make nitroglycerine if you're brave enough

 

[TechnicAl]

Can be used to make nitroglycerine if you're brave enough

Which is what happens if you make Nital the wrong way round

Acid to alcohol NOT alcohol to acid

Tried it once just to see (in a fume cupboard). It went brown, boiled and started fuming............stopped it then

 

[Fintray]

Which is what happens if you make Nital the wrong way round

Acid to alcohol NOT alcohol to acid

Tried it once just to see (in a fume cupboard). It went brown, boiled and started fuming............stopped it then

Perhaps just as well you did!

http://news.bbc.co.uk/1/hi/england/bristol/7330656.stm

 

[Shox Dr]

Perhaps just as well you did!

http://news.bbc.co.uk/1/hi/england/bristol/7330656.stm

You can't legislate against idiots. What did he think he was doing.

By the age of 8 I had been taught never to add anything to an acid, ALWAYS add the acid, that way you have the smallest amount of acid, that might react.

 

[awemawson]

Lucky I bought a 5 litre bottle a couple of years back then

 

[TechnicAl]

Perhaps just as well you did!

http://news.bbc.co.uk/1/hi/england/bristol/7330656.stm

Wow. He must have got it really wrong. "Mr Baird was sizzling"..........thats a sobering thought.........

 

[Richard.]

Wow. He must have got it really wrong. "Mr Baird was sizzling"..........thats a sobering thought.........

I only use nitric acid/methanol mix for etching.
Obviously we were shown how to make the solution correctly and in the correct sequence.
Another question springs to mind about that particular case
Why was mr Baird not wearing a full face shield and gloves when dealing with acid.
Obviously he c##ked up the marriage of the two chemicals but PPE could of saved him a few scars and pain.
It's instant dismissal for us if we are seen not wearing it which is right. A drop of that neat acid in your eye is the last thing you need.

 

[bigbadbugga]

Here ya go, here's how Jody does it...