What coating/plating is this?

[SED]

What is the brownish/gray coating on the spring tubes, fork links, shifter and ratchet, cush-drive, seat springs?  The catalog photo seems to show the same coating - not chrome or paint.


          
             

[RinkRat II]

   A) Patina
   B) Iron Oxide
   C) Salt Air Corrosion

       Paul B

[fotoguzzi]

What are "spring tubes"?

[SED]

What are "spring tubes"?

Hold the springs for the swingarm.

[oldbike54]

 Probably a form of Parkerizing .

 Dusty

[redhawk47]

   A) Patina
   B) Iron Oxide
   C) Salt Air Corrosion

       Paul B

in other words: rust

Dan

[SED]

Probably a form of Parkerizing .

 Dusty

It isn't as corroded as the chrome so I discounted iron phosphate Parkerizing.  Is there a way to make it more weather resistant?

[oldbike54]

It isn't as corroded as the chrome so I discounted iron phosphate Parkerizing.  Is there a way to make it more weather resistant?

 Not an expert , but I am aware of different techniques using zinc or manganese that give different results . We need someone who knows what the Italians were doing in that era .

 Dusty

[SED]

Not an expert , but I am aware of different techniques using zinc or manganese that give different results . We need someone who knows what the Italians were doing in that era .

 Dusty

I've seen that internet searching but they said both manganese and zinc needed a top coat.  Paint and oil were the recommended top coats.

[oldbike54]

I've seen that internet searching but they said both manganese and zinc needed a top coat.  Paint and oil were the recommended top coats.

 True , Parkerizing is really just a base coat , which I think is what you are seeing .

 Dusty

[SED]

   A) Patina
   B) Iron Oxide
   C) Salt Air Corrosion

       Paul B

    

[larrys]

Zinc park is gray. Manganese park is black. The British used to use manganese park with black paint on top for their military firearms. Most other countries used manganese park and oil. That doesn’t look like parkerising on that bike.
Larry

[Groover]

Makes me think of the same metal type used for strapping steel to strap heavy bundles, also used on stuff that needs to click back into place in mechanical-type gizmos. Springy type metal, typically dark, Just a guess. I'm also intrigued.

[SED]

Groover, I've been thinking the same thing.  I've got 100 year old pliers that are bare steel and don't rust easily.  Something about the steel protects it.  Modern Channel Lock pliers have the same type of coating at the teeth.

I'm starting to think it might be zinc or manganese phosphate with an oil film.  In the past I've used something called LPS3 that goes on as a liquid, but dries to a waxy film.  Once wiped off a thin brownish film remains.  Some of the brown may also be very small rust specks beginning to form.

In the photos, the fasteners, moving parts and links all seem to have the same coating and many repop parts come from Italy coated in black manganese rather than chrome, zinc or cad that is much more common now - even spokes are black.

Was there ever an industrial process where zinc or manganese phosphate coating was then coated by, say, boiling in linseed oil?

Any other ideas?

[John A]

[quote author=SED link=topic=103899.msg1645496#msg1645496 date=1577121106
Was there ever an industrial process where zinc or manganese phosphate coating was then coated by, say, boiling in linseed oil?

Any other ideas?
[/quote]


I think that’s it, linseed oil. Raw linseed oil does not dry,  boiled linseed oil dries into a very durable coating.  Either will spontaneously combust and will burn your shop down if rags are not kept in airtight containers so it’s use has largely been discontinued.  On gunstocks or other bare wood you rub in raw linseed oil, then boiled.  Then if the wood is scratched it won’t even be noticeable.  On ferrous items the boiled is baked on.

[Rough Edge racing]

 I have used a product called CLR on mild rust to clean it up and the end result is a smooth brown patina....Custom car and bike guys use it .....Then they wax over it to ffer a bit of protection...Some even clear coat it

[John A]

If you can find battery terminal protective spray that is not red,  it makes a good coating on nuts and bolts.  I used to be able to find it in silver but haven’t found that in years

[SED]

Thanks for the help guys! 

Might have to set up the camp stove in the driveway and boil some nuts in linseed oil!   

[Muzz]

I have used a product called CLR on mild rust to clean it up and the end result is a smooth brown patina....Custom car and bike guys use it .....Then they wax over it to ffer a bit of protection...Some even clear coat it

Went and had a look.  I always assumed it was Phosphoric acid at the heart of it but it is something called Sulphamic.  Never heard of that one.

Googled it,  H3NSO3.  Very useful sort of acid indeed.