Any Chemists out there??

[spread-tee]

I need to get rid of some Chrome plating from parts of a motorbike I am restoring. I have had some quite pleasing results Nickel plating bolts, nuts, spacers etc for the purpose of corrosion proofing and to give a little shine, so I thought I would have a go at the kickstart and gear lever. The problem I am having is no matter how I prepare the surface, where the original chrome is intact the new plating will not stick, it just wipes off with a damp rag.
I have tried immersing in strong caustic soda for days, various types of sanding/wire brushing, even tried reverse plating all to no avail.
Any ideas??

Also need some bits turned up on a lathe, may have asked this one before.

Desp

[AE-NMidlands]

I understand that HCl will strip Chromium - my boss in the lab told me that our gents urinal flush bar was plain copper because he caught the cleaner applying lime-scale cleaning acid to it and saw the chrome disappearing! The rest of the building was spared that treatment.

https://www.evilution.co.uk/mod/removin ... h-acid.htm has other recipes too...

[NoraBatty]

Hydrochloric will do the job, but more importantly what is the underlying metal? because it may also eat that too if you arent careful.

[Countrypaul]

Hydochloric acid is also known as brick acid (just in case you didn't know).

[Paul_F]

Would you not be able to use Electroless nickel plating?

[Moxi]

Hi Desp,

Have a read of this as its very informative

https://www.runsom.com/technology/ways- ... 20chromium.

Moxi

[spread-tee]

Thanks for the replies chaps, I am using diluted brick acid for the pickle before the plating , but even undiluted I don't think it is very strong, I also like the idea of using Caustic as the base material is steel so HCL could do some damage, but I will wizz out and get some spirit of salts tomorrow, I think that is about 35-40% HCL.
Paul I don't know anything about electroless Nickel plating, I will have a google up Thanks.

ATB

Desp

[Countrypaul]

Concentrated hydrochloric acid is about 38% (any higher is very prone to loss of strength) also known as muriatic acid and spirits of salts, brick acid is usually 18% iirc.

I thought I read somewhere that only 10% strength is needed to remove chrome plating though.

[spread-tee]

Thanks,

I just dunked the kickstart lever in some Sika brick and patio cleaner that just states <10% HCl and there doesn't appear to be much activity yet, even on the bare steel, it's only been a few minutes though. I'm gonna try to find some spirit of salts drain unblocker and see what happens.

I'll probably get a visit from the bomb squad

Desp

[Stinsy]

Make sure you only use it outside and don't inhale any fumes...