Etching of steel prior to nickel plating

[Clive BarkerParticipant @clivebarker72854]

[Clive BarkerParticipant @clivebarker72854]

I wonder if anyone can advise about alternatives to hydrochloric etching prior to nickel plating. This is something new for me. I have watched a few videos, some of which advocate etching after surface preparation and degreasing. Unfortunately hydrochloric acid doesn't seem to be easy to purchase in small quantities. Some advocate using concrete/slab cleaner but it seems they don't all contain hydrochloric acid and some might even be alkali.

Is this etching just a stage of the cleaning which could be done other ways? Are there alternative ways to etch the steel?

Any advice would be most welcome.

Thank you, Clive.

[Paul LousickParticipant @paullousick59116]

My local hardware store sell hydrochloric acid in 500ml (and larger) bottles. Swimming pool supply shops also sell it.

Muriatic acid is a form of hydrochloric acid. But while hydrochloric acid contains only HCI molecules, muriatic acid is made up of HCI molecules as well as impurities such as iron. (used as a flux when soft slldering galvanizes steel)

Paul

[Marcus BowmanParticipant @marcusbowman28936]

You might try http://www.gaterosplating.co.uk

They sell plating kits, and the nickel plating kit contains a dry powdered acid. They sell replacement packs of chemicals for their kits, so may sell the cleaning acid separately. I have one of their kits.

There are several other suppliers of similar kits and possibly replacement chemicals, such as

http://www.frost.co.uk

http://www.classic-plating.co.uk

and Chronos.

Marcus

[Kiwi BlokeParticipant @kiwibloke62605]

Posted by Paul Lousick on 25/07/2021 23:55:38:

Muriatic acid is a form of hydrochloric acid. But while hydrochloric acid contains only HCI molecules, muriatic acid is made up of HCI molecules as well as impurities such as iron. (used as a flux when soft slldering galvanizes steel)

'Muriatic acid' is an archaic (although stubbornly current in USA) synonym for hydrochloric acid – without impurities. I think there's confusion here with 'killed spirits', zinc chloride solution, which is traditionally made by adding metallic Zn to HCl until no more Zn will react (the fizzing stops). Or you can buy Baker's Fluid (if it's still available…). It's an aggressive (and corrosive) soft soldering flux.

HCl used to be available to bricklayers for cleaning mortar off bricks ('brick acid' ). Easily available as such in NZ, but dunno about elsewhere.

Edited By Kiwi Bloke on 26/07/2021 09:04:33 – blasted silly winking face thingie removed.

Edited By Kiwi Bloke on 26/07/2021 09:06:00 – typos, and more typos…

Edited By Kiwi Bloke on 26/07/2021 09:08:42

[Clive BarkerParticipant @clivebarker72854]

Thanks all for your helpful comments and suggestions. On following the links I can see that HCL is available and that there are several alternative avenues. Many thanks once again. Clive.

[Oily RagParticipant @oilyrag]

Many moons ago I had an acquaintance who was involved in the electro plating business. On a visit to his works he showed me the plating process which was interesting to say the least!

Firstly the parts went into a high detergent wash tank to remove grease and oil, secondly a pure water wash tank, then through a drier before going into Hexavalent Chrome to etch, then a two stage wash, followed by a copper plate solution (which was IIRC copper dissolved in sulphuric acid – copper sulphate in effect ), followed by another double wash, followed by a electro plating copper bath, another wash, then a nickel plating bath, where it was subsequently diverted off line to either a finish wash for dull nickel plate, or a secondary nickel bath for a bright nickel plate. Other parts due for chroming went on their way to the final chromium baths and washes. I was staggered at the amounts of water used in the process – and also just how dangerous Hexavalent Chrome is (was! since it has now been virtually banned ) a piece of paper dipped in the Hex Chrome tank burst into flames when exposed to air!

Martin

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