finishing.com -- The Home Page of the Finishing Industry
no_pop_no_spam
HomeFAQsBooksHelpWantedsForum  letter 36816

Serious Education ... plus the most fun you can have in metal finishing.

Stripping of bronze plating




Strip bronze from brass parts

(2005)

Q. Hello all,

We are looking for a stripper or a process recommendation that completely removes an alloy of Copper-Tin-Zinc plating from brass parts without etching the base brass metal.

This is in order to be able to strip and replate process rejections from our bronze plating line.

khozema
Khozem Vahaanwala
Saify Ind supporting advertiser
Bangalore, Karnataka, India

saify logo


(2005)

A. Hi Khozema,
Combination of hydrochloric acid, sulphuric acid and hydrofluoric acid in an electrochemical action should strip the deposit on brass substrate.
Well maintained stripping bath will not etch the brass.
Even though I haven't used this formulation to strip copper-tin-zinc alloy, this stripper will strip any deposit from brass.
Unfortunately I don't remember the ratio of the above acids (it's almost 4 years since I have used it). But if you play with these three chemicals for few days you can optimise the stripper bath.

Regards,

Venkat Raja
- Kitchener, Ontario, Canada


(2005)

A. I have to disagree with the stripping process aforementioned. Considering that bronze contains a lot of copper in the alloy and brass does too, I think it's extremely unlikely you'll strip bronze from brass and not damage the brass material. I'd do that on a very small scale first to make sure you don't damage the substrate.

Daryl Spindler
Decorative chrome plating - Nashville, Tennessee



Stripping bronze plating from steel parts

June 26, 2013

Q. It is being suggested to me that ammonia solution (specific gravity of 0.89) diluted to 10% with demineralised water could be used to strip bronze plating from alloy steel parts. I have experience of proprietary stripping solutions such as Enstrip S, but not of the above. Will this be acceptable for steel parts? And how will the solution evolve over time, i.e. does it just become ineffective and therefore need discarding or can it be replenished by adding fresh ammonia solution?

Simon Ford
- Wolverhampton, UK


August 30, 2013

A. We used Pure Assay Ammonia SG 0.890 with no dilution. It takes about five days in total. The ammonia was replaced daily, and the parts were agitated regularly. A light rub with "scotchbrite" was used to remove any black deposits left on the parts. No pitting or corrosion of the base metal was observed.

Jonathan Fletcher
- Birmingham, Warwickshire, England



Proper solution ratio for stripping bronze plating off racks

December 20, 2016 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

Q. Morning all!

I need some help. We just made some improvements to our plating strip tank. We've added a Carbolux unit to pull out carbonates which significantly lessens our disposal and haul-off costs.

What suggestions can you guys give me to help optimize my cyanide strip solution to remove bronze from our plating racks?

What's new for us is actually controlling the chemistry for the stripping solution (1100 gal of sodium hydroxide & sodium cyanide @ 140 °F). Before the Carbolux, we ran the tank until it "died" (the carbonates maxed out) and stopped stripping racks. We didn't really worry about anything but the carbonate levels (testing-wise). We would just dump the tank and re-charge fresh.

Now, we're adjusting chemistry but we're not seeing the expected bath life (we are able to get double to triple the bath life, but expected at least 4 weeks min). The solution is doing odd things, like leaving a heavy white film on the racks (even when the carbonates are relatively low) after they are pulled -- fully stripped but coated.

I'm guessing that it's a ratio issue with the chemistry, but I haven't had a chance to really test it.

Can you all help me out?

Thanks!
Dawn

Dawn Baeckeroot
- Bellaire, Michigan
  ^- Privately contact this inquirer -^

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & DevicesUsed & Surplus


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.