How might I do this?

[texaxile]

Hi,
I've recently obtained some parts which are outer trim, but instead of being plastic and black as per the original they are stainless steel. someone has suggested I get them zinc coated and then either vinyl wrapped or "passified" - which I've never heard of before.

I had a brainwave and after some blank looks and googling, I realised that the guy informing me to do it was Dutch, so I looked it up and got this (google : passified Dutch):

"Before coating, steel is alkaline de-greased, phosphated and passified".

Can someone perhaps explain what treatment he is suggesting please?. Also, is it necessary to do it or can I simply degrease and get them sprayed matt black?.

TIA Pete

[shakotan]

texaxile said:

Hi,
I've recently obtained some parts which are outer trim, but instead of being plastic and black as per the original they are stainless steel. someone has suggested I get them zinc coated and then either vinyl wrapped or "passified" - which I've never heard of before.

I had a brainwave and after some blank looks and googling, I realised that the guy informing me to do it was Dutch, so I looked it up and got this (google : passified Dutch):

"Before coating, steel is alkaline de-greased, phosphated and passified".

Can someone perhaps explain what treatment he is suggesting please?. Also, is it necessary to do it or can I simply degrease and get them sprayed matt black?.

TIA Pete

Passivating is just plating. Black screws you see about are black zinc passivated.

[Equus]

The term you are probably looking for in the UK is 'anodised'.

[mph]

Equus said:

The term you are probably looking for in the UK is 'anodised'.

Anodising is an electrical process, passivating is a chemical one.

[Equus]

mph said:

Anodising is an electrical process, passivating is a chemical one.

Wikipedia disagrees with you and defines anodising as 'an electrolytic passivation process'.

But regardless: we're guessing on a translation of meaning from Dutch coloquial to English, not trying to win a competition for most anally retentive ahole on PistonHeads.

Passivation of stainless steel results in a dull silver finish, which is clearly not what is being suggested if the OP requires them to be black. Black anodising, on the other hand, is perfectly possible.

[T70RPM]

I'm fairly sure CAD is silver & CAD & PAS is gold.

[shakotan]

Equus said:

mph said:

Anodising is an electrical process, passivating is a chemical one.

Wikipedia disagrees with you and defines anodising as 'an electrolytic passivation process'.

But regardless: we're guessing on a translation of meaning from Dutch coloquial to English, not trying to win a competition for most anally retentive ahole on PistonHeads.

Passivation of stainless steel results in a dull silver finish, which is clearly not what is being suggested if the OP requires them to be black. Black anodising, on the other hand, is perfectly possible.

Passivation can be various colours depending on the chemicals used. Black hardware (screws, nuts bolts) are black passivated.

http://www.actonmetal.com/passivation_stainless_st...

[52classic]

Are they really stainless! If so I'd forget about passivation or plating of any kind, no vinyl wrap either.

Why not get them powder coated black? This can be done very cheaply when the supplier is running something else in the same colour.

[Mike-tf3n0]

Cad is cadmium plating, now illegal as it is a heavy metal. Pas is passivating which is the gold colour you find on most woodscrews and the like and is additional protective microcoating created through chemical reaction with the base material. Anodising is also a protective chemical process invariably used on Aluminium but not steel to inhibit oxidisation. If your bits are stainless then leave them as they are.

[InitialDave]

I use Plastidip-type spray (actually Halfords own brand is what I have on hand at the minute) to give a "plastic" look to stuff like that, such as parts I've 3D printed. It's only a tenner for a can, and you can peel it off if you don't like it, so give it a go.

Cadmium plating can still be done if you want it, but I don't think that's what you're after for this application.

[texaxile]

Thanks for all the replies, I had no idea of what the process was.

I might go for powder coating, merely because it is easier to find a powder coating company than it is one who specialises in the passivation process (locally at least). It is a long lasting improved aesthetic look I'm aiming for, a smooth finish on the metal and hopefully one which is durable.

The original parts are plastic and as such after 35 years are brittle (they are windscreen trim surrounds) I've broken two already and they are NLA from Mitsubishi - so I managed to source some from the Philippines while on holiday and bring them home.

Once again the PH collective delivers. Virtual beers all round, cheers guys.