hardcoat chrome plating?

[Rothrandir]

looking through the yellow pages, i wasn't able to find anyone who could annodyze ( /ubbthreads/images/graemlins/frown.gif ), but i did call a plater, and upon asking what could be done with aluminum, he said he could "hardcoat chrome plate" (or something like that... /ubbthreads/images/graemlins/crazy.gif).

i asked how durable it was and he chuckled and said "very", but i have no idea, and haven't even heard of it.
who knows, maybe it'd durable in some applictations but not suitable for flashlights?

he said the piece would need to be sandblasted prior to plating...

i'm just wondering if anyone has any experience with this type of plating. i'd be interested in trying it out for myself, but they have a huge minimum lot requirement /ubbthreads/images/graemlins/frown.gif

 

[jtice]

I think that is similar to what you would find on a bikes handle bars.
Basically chrome, but alittle less flaky.

Should hold up well, but can tarnish easy.

 

[HarryN]

The answer on chrome on Al is correct. Another place you see chrome on Al is in most modern car trim parts. It is very hard, but will peel over time with extensive outdoor exposure.

Chrome plating is becoming less popular because of the pollution from chrome ions in ground water. (It Cr 6+ is a strong carcinogen) Usually you find anodizers near large Al fabricators. The Thomas Register (the book at the library) is a good quick source.

Usually, there is a $ 50 - 80 min order. I think I saw a CPF'r that did his own, but you need to be serious and acid savvy to take this on.

I have samples from platers of Type II - the colors are great, but will scratch. If you like colors, use silver so the scratch will not show up so much when it goes down to the Al. Type III is trickier to get - basically, you do this process in cold H2SO4 instead of heated.

 

[wasabe64]

Roth, could he be talking about Hardchrome?

Hardchrome does provide phenomenal wear resistance for moving parts, but it is not as tough as HAIII.

Looks great on guns, it may be worth trying on a flashlight...

 

[Jets22]

I have done Hard Chrome on 45 auto slides and frames I have modified, VERY DURABLE stuff actually looks like Stainless steel when satin finished.. If the substrate is soft (like aluminium) it will not be as durable due to the softer material .. However, if you don't drop it alot or smack it into something hard should last a long time..

Jets

 

[cy]

I used to do Hard Chrome, regular chome plating, plating on alumimum and anodizing. Ok, here comes the disclaimer: I used to do this a long time ago and proccess' may have changed.

Jet 22 is fairly accurate but everyone else above is somewhat off. Fairly common to have misconceptions about plating.

1. Hard chrome is one the most durable surfaces known (plating wise).
2. It is very difficult, almost impossible to hard chrome aluminum. this is due to fact that its' very hard to chemically bond copper (base metal) to aluminum. the closest metal that bonded well to aluminum was electroless nickel.
3. Regular chrome is very thin, just flashed on top of nickel. Typically 1/2 mill or less. Hard Chrome is totally different (2-30+ mils thick). The part is subjected to very high amp loads in the chromium bath, up to several hours VS a few minutes for std chrome. Back to the bonding problem with cooper to aluminum. At these extreme loads, the base metal is literally pulled off the aluminum.
3. Hard chrome is way more durable than HA. Anodizing is not even close.
4. You will never see hard chrome done by a hobbyist. Chromic acid is one of the most poisonous substance around. the feds regulate the plating shops on its disposal.

If you want durabilty I would never recommend plating of any type on aluminum. HA is fairly durable as is.

Please correct me if I'm wrong in any of this.

Thanks,


CY

 

[Jets22]

CY..your 100%. the main reason alot of shops do not offer this anymore is the cost to get rid of the old material has increased 3 times..Most go over-seas where the EPA restriction are .....less "observed" to say the least..

I started out with using EN and really like the stuff.. The military has just signed to have their non EPA friendly Cad plate removed from the parachute rigs and then EN plated.

As Jim knows, I'm the big TiN
plate fan these days though..

Good post

 

[Rothrandir]

thanks guys /ubbthreads/images/graemlins/smile.gif

i'll probably stay away for now, but maybe some day when i'm bored i'll go out there to see if they have any samples i can look at...