removing zinc chromate

I need to strip zinc chromate from some bolts and hardware to age them. What will do it?

 

I've soaked new bolts and nuts in Coca-Cola for a couple days to give them an aged look. It will take the shine off them, and stain them slightly.

 

Exactly correct. If you know someone with a malt shop try and get some coke syrup from them it is more potent than canned coke.

But Alchemy is correct 100% here.

 

Cant you buy the soda syrup refills at Costco and Sams? think they have the setups for home soda dispensers.

 

Coke has phosphoric acid. In a pinch, you could actually buy real phosphoric acid. Try Krud Kutter rust remover. You could dilute it.

http://www.krudkutter.com/msds_sheets/RG_msds.pdf

In a pinch, it can also be used to remove rust. Don't use on non-iron based metals (aluminum, tin, pot metal). De-rusted parts are also more rust resistant.

 

yea but a can of Coke is cheap with a little luck someone might offer you one.

 

Coke is like WD-40......many "interesting" uses.
Works great fro freeing up seized, old snowmachine engines that have been sitting all summer....haha

 

I'v used muriatic acid . works fast but don't breath the smoke!!!

 

I give you that. If you have a choice, maybe diet coke? Maybe the sugar in the coke might slow the process down and the diet wouldn't make your bolts all sticky?

 

A plating shop would use acid.

 

Be careful with Zinc Chromate that stuff is a carcinogenic. Don't breath the dust.

 

Concrete cleaner (acid)
Coke that has been boiled (less water) also good on bumpers
Drain-O
lemon juice
It depends on the "look" you want.
I have used these and others to"age" metals.

 

Muriatic acid works great and fast.
You can buy a gallon at most any hardware store. Perhaps even smaler quanities if needed. Watch out for the fumes though!

 

Muratic Acid. works in minutes not days, I cleaned a fuel tank with it and a box of BBs, nuts and bolts, sloshed it around, man that stuff works well, heed the warning, dont inhale the fumes, wear safety goggles and rubber gloves, it'll do to your skin what it does to them bolts

 

You could also bead blast, then run them over a wire brush on a grinder. Leave them outside in the wet weather for a couple of days and that should do the trick.

 

Bead blasting and wire brushing are ok for the bolt heads, but the threads are damaged more by those methods than by acid striping. That said, if fasteners are left too long in strong acid they can be ruined by that too.

 

I used to run a Zinc Chromate plating line. We stripped with nitric acid, muriatic acid is dilute nitric acid (if I remember right.) All the warnings about the use of acids should be well-heeded. Zinc plating uses some really nasty chemicals that should be taken seriously. Only in a well-ventilated area (outside), gloves, faceshield, no flames-cigarettes-children....be smart and careful if you use strong acids.