Etching zinc plating

[bouncingVman]

 I'm just throwing some ideas around...

I was thinking of a way I can dull the zinc plating on the head bolts of my bike without ruining the anti-corrosion properties of the plating. The idea is to give it more of a darker color. Anyone have any ideas?? I have one that is already that way... and I'm thinking that I like it... and want the rest to look the same.

[04glide]

Why don't you just buy some of those dorky head bolt covers like I did.

[crash1292]

leave it out in the weather for a while

[bouncingVman]

Why don't you just buy some of those dorky head bolt covers like I did.

LOL. 

The thing is I kinda like the look of the bolts sticking out. I think I have this one figured out... stop looking at them. Or maybe buy some of those dorky head bolt covers. 

[Ultrashovel]

I use 70% phosphoric acid in my shop all of the time to darken up plain metal bolts and mild steel items that I turn out on the lathe to put a rust-free finish on them. I think it would work on plating as well. By the way, the plating about which you are speaking is most likely cadmium. Zinc is used on common hardware but HD uses mostly cadmium.

Phosphoric acid is available at chemical supply warehouses but for a simpler test, I suggest getting some Naval jelly at a hardware store. It's got a very low percentage of phosphoric acid in it. Paint some on with a brush and after a while, wash it off and see what happened. You could also test it first on a bolt. It won't do anything to aluminum.

If I was going to do something like that, though, I'd probably just get a good book and forget about it. 

[bouncingVman]

If I was going to do something like that, though, I'd probably just get a good book and forget about it. 

Ultrashovel,

LOL. Good advice. And put a cover over the bike. 

I thought about doing a test on an old spark plug, bolt or something similar... maybe use diluted muratic acid... but that could be really bad if it got on the paint. Cadmium probably would disapear in the presence of acid so that wouldn't be good either. I know muratic acid will etch chrome so if I were to do anything... and its a big IF.... I might try to dull the finish on those cheap taiwan chrome headbolt covers and then put them on the bike. I like the idea of having something with a darker machine finish.

Like I mentioned... just throwing some ideas around here until spring. 

[Ultrashovel]

If I was going to do something like that, though, I'd probably just get a good book and forget about it. 

Ultrashovel,

LOL. Good advice. And put a cover over the bike. 

I thought about doing a test on an old spark plug, bolt or something similar... maybe use diluted muratic acid... but that could be really bad if it got on the paint. Cadmium probably would disapear in the presence of acid so that wouldn't be good either. I know muratic acid will etch chrome so if I were to do anything... and its a big IF.... I might try to dull the finish on those cheap taiwan chrome headbolt covers and then put them on the bike. I like the idea of having something with a darker machine finish.

Like I mentioned... just throwing some ideas around here until spring. 

Muriatic is rather violent compared to phosphoric acid. Phosphoric is very sow-acting and will give a visual change in a few mnutes when it's concentrated. It is the basis for the original Harley "Parkerizing" process, although that's done with hot acid and some other additions.

Good luck.

[bouncingVman]

Thanks 

[bouncingVman]

Ray,

You've got mail

Thanks

[ricochet]

Do you think it is cadmium?  I thought cad was banned in the states a while ago and Harley would shurely comply.

ricochet

[hdjax2]

How about some gun bluing solution? Just a thought

[bouncingVman]

I always thought my spokes were cadmium plated. They sure didn't hold up... that's for sure.... anyway no matter.... they're gone like last months underwear. LOL... went with stainless steel instead.

Thought about gun bluing solution too... that's kinda like "Parkerizing."

I got a set of used headbolt covers from rayfeldt. My idea is to try fuming them with muric acid to discolor the chrome.   

If it weren't winter... I would find it hard to believe that this subject was ever dreamed up. LOL. 

-BVM

[Ultrashovel]

Do you think it is cadmium?  I thought cad was banned in the states a while ago and Harley would shurely comply.

ricochet

Cadmium is poisonous like many other heavy metals but Harley-Davidson still uses it since it's not been banned. It's widely used in industry for coating parts to prevent corrosion. It does turn dark after a few years if exposed to the atmosphere. It's a plating process done with acid and electric current like other metals.