Anyone here with basic chemistry skills to help with plating pickle?

[rcx132]

Can anyone decipher this simple recipe for making pickle for preparing parts for plating.

I was told to use 10-15% HCl as a pickle. So I took some HCl 36% and mixed it with 1 : 1.9 with water which, according to my calculations takes it to 12.5% (36/12.5 - 1 = 1.9). But the pickle is super strong and looks way too strong.

So I checked the recipe in a textbook, scan below, but I can't decipher the instructions.



Also does anyone have a recipe for zinc plating electrolyte? My kit came as 150g/l Ammonium chloride and 62.5 g/l Zinc chloride. But my textbook says to use 120 g/l Ammonium chloride and 20 g/l zinc chloride.

 

[rtbcomp]

Choose either imperial or metric measures, metric is easier.

Take 200 mls of conc. acid and add it to 1 litre of water to dilute it.

You'll need to show you are a business before you can (legally) obtain conc. hydrochloric acid.

 

[rcx132]

W

Choose either imperial or metric measures, metric is easier.

Take 200 mls of conc. acid and add it to 1 litre of water to dilute it.

You'll need to show you are a business before you can (legally) obtain conc. hydrochloric acid.

What concentration is concentrated HCL? I have a bottle of HCl 36%.

 

[rtbcomp]

http://www.sigmaaldrich.com/chemist...technical-library/reagent-concentrations.html

https://en.wikipedia.org/wiki/Hydrochloric_acid

I would say 36% is concentrated enough for your purpose

 

[rcx132]

Take 200 mls of conc. acid and add it to 1 litre of water to dilute it.

That equates to mixing the HCl 1:5.
By my calculations (not confident in them), mixing 36% HCl at 1:5 would take me to 6%.
I currently have 12.5% and seems too strong. Wikipedia says that 18% is used for pickling.

So not sure which one to use

 

[Maker]

You'll need to show you are a business before you can (legally) obtain conc. hydrochloric acid.

Strangely, this isn't true for sulphuric acid, we've got 5L of 96% in the shed.

 

[rtcosic]

'conc HCl' is near enough 100% for the purposes of this discussion.

So 200 mls of 100% HCl added to 1000ml of water gives you 1200 mls in total.

200/1200 = 1/6 = 16.7%.

So, as these are not critical values somewhere around 15% is fine.

12.5% is fine.

18% is fine.

10% would be fine - so if you think your pickling solution is a little too 'fierce' for your application dilute it down to 10%


You're overthinking this.