- Thread starter stuvy
- Start date
I think it is passivating and before that you put a layer of electrolytic galvanizing under it.
You can maybe use this with google translate?
https://oldtimerrestauratie.com/ind...gorien/oppervlaktebehandelingen/106-verzinken
Don't thik this will work with stainless though, maybe Titanium nitride like on toolbits?
You can maybe use this with google translate?
https://oldtimerrestauratie.com/ind...gorien/oppervlaktebehandelingen/106-verzinken
Don't thik this will work with stainless though, maybe Titanium nitride like on toolbits?
Parm
Respect The Sound System
- Messages
- 18,009
- Location
- Towcester
Now for the serious answer, it’s called passivation. Definitely works on steel. I’ve seen the process at Caterpillar, they do it on the steel hydraulic pipes. It’s a form of trivalent chromium. They use this in preference to normal hexavalent chrome as it’s self healing. Ie if it gets scratched the anodising heals to prevent rust getting in.
It always has a dull finish, never seen it that shiney and never seen it on SS
Brad93
Member
- Messages
- 19,089
- Location
- Essex, United Kingdom
Anodising is building a thick oxide layer of aluminium oxide with a dye added for colour.
with steel you can only really plate it. So you’d get you’re gold zinc plating, silver or black and blue through nitriding or blueing.
you could get bright blue or bright gold through nitriding like they get on drill bits. Can’t imagine it would be cost effective.
with steel you can only really plate it. So you’d get you’re gold zinc plating, silver or black and blue through nitriding or blueing.
you could get bright blue or bright gold through nitriding like they get on drill bits. Can’t imagine it would be cost effective.
willie.macleod
Member
- Messages
- 898
- Location
- Western Isles, Scotland
Frost sell a zinc passivate kit which they claim will give you a gold iridescent finish.
https://www.frost.co.uk/superbright-zinc-plating-complete-kit-with-blue-yellow-passivate/
https://www.frost.co.uk/superbright-zinc-plating-complete-kit-with-blue-yellow-passivate/
Brad93
Member
- Messages
- 19,089
- Location
- Essex, United Kingdom
Frost stuff is usually pretty decsnt, worth a go
stuvy
Member
- Messages
- 9,304
Agroshield
Member
- Messages
- 6,065
In addition, as I understand it, hexavalent chromium is also very nasty for health and environment.
The Binky people are putting the same passivate on all their nuts and bolts so you could see where their kit comes from.
Probably not good to use it on any type of spring (high carbon) material as hydrogen embrittlement is possible.
rtcosic
Forum Supporter
- Messages
- 2,909
- Location
- Warwickshire
1960's would have been cadmium plating wouldn't it? Zinc then blue-yellow passivation would be the modern less hazardous replacement process?
I'm sure @Parm has some documentation about that 'back at base'. Or he knows a man who can!
I would use passivated zinc to replicate the original coating as linked by @willie.macleod
I'm sure @Parm has some documentation about that 'back at base'. Or he knows a man who can!
I would use passivated zinc to replicate the original coating as linked by @willie.macleod
Munkul
Jack of some trades, Master of none
- Messages
- 7,788
- Location
- Cumbria
Not to mention, a lot less toxic in-process!
Technically it's a plating technique which is self-passivating, on top of the galvanising . Both Cr6 and Cr3 are both passivating, but cr6 is "chromating" with a thicker layer. Cr6 coatings traditionally have self-healing properties, cr3 coatings do not. Although maybe they have developed self-healing Cr3 coatings by now... you can get yellow chromate colour with both Cr types now..
Last edited:
Woody.v8
Blue gluer
- Messages
- 4,209
- Location
- staffs
My local plating place has stopped doing the gold passivate now and only do silver, He said something about them banning one of the chemicals ?, I will ask him next time.
The silver is better for corrosion resistance but it seems to go on thicker so can cause clearance issues on mechanical fit ups.
The silver is better for corrosion resistance but it seems to go on thicker so can cause clearance issues on mechanical fit ups.
Parm
Respect The Sound System
- Messages
- 18,009
- Location
- Towcester
Cadmium plating is bad news, but no worse that hex chrome.
With good control measures anything is possible. I do believe some specialist military applications still use cadmium plating
Is it not an option to send the pieces off to get them professionally plated?
These used to be one of the best in the country (although I haven't been there in 15 years)
http://derbyplating.co.uk/
Parm
Respect The Sound System
- Messages
- 18,009
- Location
- Towcester
I know that place very well, done alot of work there as a consultant. They are very good and widely respected in classic car restoration circles. They produce very good work.
I think I suggested them a few weeks ago, think it may have been for @mtt.tr ?
AndersK
Member
- Messages
- 1,490
- Location
- Sweden
Isn't it the process of Cd plating that is hazardous and not the coating itself?
Yellow chromating on the other hand is both and why it's banned within EU since sep 2017, for automotive use.
Some of the new passivation processes produce quite yellow result but not as the old.
Hard chromium plating is still allowed, for a short while, since the hexavalent chrome isn't transfered to the product.
Parm
Respect The Sound System
- Messages
- 18,009
- Location
- Towcester
Any plating process is quite hazardous
rtcosic
Forum Supporter
- Messages
- 2,909
- Location
- Warwickshire
Yes they do. No 2 son was responsible for the line that plated shell cases for a Royal Navy contract. Crown exemption and all that?
AndersK
Member
- Messages
- 1,490
- Location
- Sweden
Yes of course, but question was if the finished coating itself is hazardous
