Splotchy-looking nickel finish

[vic valis]

Having some trouble getting even coverage with the Plug 'n Plate kit on the pieces I'm plating... at an arms' length, in indoor lighting, the finish looks pretty good, although smeared with fingerprints. Up close, it looks like you can see the overlapping of uneven coverage. Some of it refuses to polish out. Think some of this may be from the brush-coating; some of the dark streaking just wants to stay. Some idges and a few spots just do not want to accept the plating. I'm thinking of carefully recleaning and re=polishing what I have done so far (the plating seems very good, just differes in color) and giving the parts a final overall coat using the dip method, on the assumption that what looks like overlap from several plating sessions is indeed overlap. Any idea what advantages/disadvantages to this approach? Any problems woth plating over previous layers one more time?

jeff

[mcaswell]

Yes, sounds like a cleaning issue. You don't mention the base metal or what sort of plating you're doing?

If you're nickel plating (or copy chroming) over existing nickel (or copy chrome) plate, you will need to activate the nickel using a weak solution of muriatic acid.

[vic valis]

The base metal was brass, and after some recleaning I was able to plate the entire surface. Some of what looked like overlap turns out to have been scuffs on the brass, so that I can live with: it's a hundred-year old device, I don't want to get rid of all the character. Some polishing afterwards also helped to smooth out the look of the finish. Maybe not a pefcect finish, but still pretty good. Still have other parts to plate, and will apply my newly gained knowlege knowlege. Any suggestions where Imight find muric acid in small quantities?

jeff

[mcaswell]

Muriatic acid is sold as concrete cleaner or swimming pool cleaner. Check a hardware or pool supply store.

[vic valis]

Thanks... I was looking for it by the corruption of it's spelling (muric) and was having no luck. I think somewhere either on these boards or on the Caswell site there is info on how to prepare the nickel surfaces, but was not smart enough to bookmark it (overconfidence). Could someone direct me? Also where plating over nickel where it appears in small spots on brass surfaces, will this treatement affect the brass differently, i.e.: will it affect the polished surface of the brass?

jeff

[vic valis]

Oh yeah, I should also mention that I'm using the Plug-n-Plate nickel kit... can it be adapted for reactivating the original nickel? Can the brush system be used if the spots to be reactivated are small in relation to the overall part?

jeff

[tbloss001]

Here's a little info that might help.

When I started out plating, I bought muratic acid, also known as hydrochloric acid, at a pool supply shop. The minimum I could buy was two gallons of this fowl stuff, so I used maybe two cups of it and was stuck with the rest. I had to wait until my city had a "Toxic Chemical Collection Day" to get rid of it (I don't own a pool).

Now I know that if I need a little muratic acid, I can make up a batch by mixing Sodium bisulphate powder with distilled water.
Sodium bisulphate can also be purchased at pool supply and hardware stores as a "PH Adjuster". It's also sold in jewelry supply stores under the brand name "Sparex". Also, in a pinch, you can go to your local supermarket and buy some toilet bowl cleaner called "Sani-Flush", which is basically pure Sodium bisulphate with a little coloring added to it.

Add the Sodium bisulphate to distilld water until the crystals no longer dissolve and you'll have a 20% muratic acid solution.