Sand blasting steel question

[simplyprops]

Hi all, I am doing a small project and I went to sand blast a steel workpiece. It turns out to have a very light colour as if it was anodised. Does anyone know if sandblasting a steel will cause a protective layer to form on the steel? The colour of my workpiece does not look like my original steel at all....

Also what are the ways to darken the colour of my sand blasted steel. Thanks all..

 

[Sidewinder]

Sandblasting won't give a protective layer. What type of steel is it?

SAS

 

[Zombie Killer]

You can't anodize steel. What color was the coating?

 

[GrenadeKing]

I think he's saying that, after he sand blasted it, it had a lighter finish of the same color and texture normally associated with anodized aluminum.

This is normal when steel has been sand blasted. It is not a protective coating. You need to oil it, paint it, clear coat it, or polish it... whatever. You need to put a finish on it FAST because steel will rust very quickly after it's been blasted. In fact, it's probably already starting to rust.

 

[simplyprops]

Well I'm not sure what grade of steel. Hmm...okay it'll rust that quickly? Anyway is there anyway I can dull the sand blasted colour, I mean make it like darker? Thanks all...

 

[simplyprops]

I'm actually thinking of soaking it in coke...I heard it can remove rust and darken the colour...

 

[GrenadeKing]

Coke is not going to protect the finish. Bare steel WILL rust if it's not coated in something.

As for what, that depends on how dark you want it. Oil will darken it as well as protect it or, for a more maintenance free finish, any clear coat will protect the surface as well as darken it.

The only other way really is paint or some type of chemical process.

Since it's blasted, you could rub black paint into it before you clear coat it... that could work reasonably well, if you want it that dark.

 

[cheech9898]

As GrenadeKing said. Oil will slightly darken it. Treating it with a phosphoric acid prep/rust converter (oshpo, picklex20, must for rust) will darken it a shade then the oil slightly more. Another option is to rub/buff with gun bluing solution and then oil.

 

[simplyprops]

Where can I find such phosphoric acid? Can it be purchased from any hardware store? Also what oil are we talking about here. I don't want to protect it from rust...All I want is for it to darken. It'll work on sand blasted surface too for using oil to darken it? Thanks all...

 

[GrenadeKing]

So wait... you want it to get rusty? :confused

 

[simplyprops]

No I don't want to make it all rusty. But I want to darken the colour...so oil will be good. Do you know if ginger brand oil will work?

 

[GrenadeKing]

Never heard of it. I would use a little motor oil myself. Just coat it in motor oil (fresh), leave it for a minute or so, then wipe of the excess.

Be aware that you will have the re-oil it every so often.

 

[simplyprops]

hmmm okay thanks....but it didn't seem to darken the steel after I wipe it away...