Refinishing black seatposts (Steel, XT, XTR)

[fettler]

Am sure that would have been anodised

XT posts are made of steel with an ally head. It's not painted but blacked with a surface treatment but it's not anodizing.

Just looked at my NOS one and you can actually feel little tiny burrs on the surface like the turning tool was a bit blunt or cutting speed too slow.

 

[stephan]

I think most materials can be anodised, from an alloy mix with steel to copper, most nonferrous materials can have the anodising process done. I could be wrong, does the Shimano technical data sheets state on the finish? Does a magnet stick to the seat post?

 

[fettler]

I think most materials can be anodised, from stainless steel to copper, most nonferrous materials can have the anodising process done. I could be wrong, does the Shimano technical data sheets state on the finish?

Anodising is increasing the oxide layer, on aluminium this creates a hard surface on an otherwise soft material. Trying to oxidise steel just creates rust.

 

[stephan]

Anodising is increasing the oxide layer, on aluminium this creates a hard surface on an otherwise soft material. Trying to oxidise steel just creates rust.

Am curious if a magnet gets attracted to that seat post tube.

 

[stephan]

Ah, if it is steel - it may have been Arc Coated -

 

[ishaw]

I have a very left field idea. Hear me out....

Kurust (or equivalent).

Why?

Well, I've used it on cars, it turns rust into a black, inert finish that van be painted over, but in this case I'm thinking no paint needed.

If the post is steel, perhaps you could try some and see what it does on the post as is. If it does require rust, a bit of water on the exposed tube, let a light rusting develop, the kurust on it to turn it black.

Like I said, left field, but could be a cheap solution to making the post look black from a distance, I doubt it would give you a perfect match, but who knows.

 

[stephan]

I have a very left field idea. Hear me out....

Kurust (or equivalent).

Why?

Well, I've used it on cars, it turns rust into a black, inert finish that van be painted over, but in this case I'm thinking no paint needed.

If the post is steel, perhaps you could try some and see what it does on the post as is. If it does require rust, a bit of water on the exposed tube, let a light rusting develop, the kurust on it to turn it black.

Like I said, left field, but could be a cheap solution to making the post look black from a distance, I doubt it would give you a perfect match, but who knows.

The seat post has no rust on it though, am sure it has had an Arc coating during its process from the factory on creation and finish, if its steel. (I could be wrong though)

 

[fguki]

I said: "In a perfect world!".










... where the post is made of alloy with a steel head

 

[Tootyred]

Cerakote..done it loads of times. Hard, thin, various colours. Gloss level can be adjusted by mixing and there is a clear coat option if needed for ultra shiny surfaces.

 

[Tsundere]

Am curious if a magnet gets attracted to that seat post tube.

Magnet sticks.