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View Full Version : Aluminum Surface Treatment. Chrome?



Revolution
02-11-2003, 06:59 PM
Hello...I could use a bit of advice on this.

I have a new product here, an automotive/ boat/ RV accessory, that is made of aluminum. I want this item to become and remain hi-gloss mirror shiny.

Anodizing in the usual way is out, since it just won't be good enough.

What I would really like, is if it could be chrome or nickel plated. It would look great, it would offer decent corrosion protection and wear resistance too. And, it doesn't cost a fortune.
BUT I'm fully aware of galvanic issues arising, not leastly since chrome & nickel generally want an underlayer of copper. (Copper & Al don't get along with each other). In fact, I have been told by a plating guy, that he just won't do it, because he knows that it just fizzles in a year or two.
BUT I'm also aware that chrome-plated aluminum turns up all the time on cars & motorcycles. Works fine for them.

Need this for primarily two areas. Now, for display demos in our sales center, where customers will be fidgeting with it constantly.
Then, in the real world, where hard usage and exposure to weather, salt water and other nasties might be a problem.

So, what do I do, then and now? Mirror shine, no corrosion, good wear resistance. Preferably a widespread technology as well; a special treatment available only from NASA won't help much, I'm afraid.

Teflon? Clear coat & oven bake? Chrome? Silver?
Can anyone help me? Thanks all who read this!

Forgot to say that we will be using machined aluminum bar stock, 6061 or maybe something more machine-oriented like Pb109. And that for now, I have no problem at all in doing the initial polishing.

Thanks!

jfsmith
02-11-2003, 07:09 PM
Why not try a nickle electriless plating and then clear coat the nickle?

I have nickle plated aluminum before on a couple of projects, Brownels has the stuff to do it

The clear coat you can go to one of those places that rust proofs car. You may have to reapply the clear every year or so, but I used to paint my boat regularly.

Jerry

Kevin45
02-11-2003, 08:24 PM
Do a search and check out a new product for aluminum called ZoopSeal. It seals aluminum agfainst the elements. A lot of rodders are using it. Rather expensive but good stuff.

Kevin

Kevin45
02-11-2003, 08:35 PM
Here is one site for it. http://www.rbsauto.com/NewProducts/ZPSEAL.html

Kevin

Butch Lambert
02-11-2003, 08:51 PM
I like e-nickle. I don't know about how it works in water. Butch

Thrud
02-11-2003, 11:18 PM
Get it hard anodized for best protection. Or have it plasma coated with ceramic coatings (like headers).

Revolution
02-12-2003, 03:08 AM
Okay, thanks all.
If aiming for an electrolytically applied nickel, won't I be subjecting myself to galvanic attack?
In the long run, it needs to last forever with little or no upkeep.
I like anodizing too, but have been led to believe that no anodizing treatment will allow a shine equal to that of chrome.
(Question, though...when we were kids and wanted cool lookin' bikes, we used to remove the color from anodized bike parts with: oven cleaner. Easy-Off. Takes the anodizing right off, no kidding. How?)

Thrud
02-13-2003, 12:17 AM
Oven cleaner is Sodium Hydroxide (LYE) - also used in the anodising process. So don't do that!

Jaymo
02-13-2003, 03:33 AM
Eastwood's carries a kit for polishing and sealing aluminum, such as intakes. Don't know how it holds up to saltwater.

SJorgensen
02-14-2003, 01:56 AM
I think you are fighting a loosing battle with the elements, and they will overtake you, in a year or two. Remember that the basic problem is that you want it to last forever and yet you chose a metal that doesn't exist ANYWHERE on the planet in a natural metalic state. Add a little salt and you're done! Ashes to ashes, dust to dust. If you really want it to last, why not use stainless steel?
Spence

Revolution
02-14-2003, 03:25 AM
Words of wisdom, Spence. Often we┬┤re too hung up on details to see the big picture. Wrong about aluminum not occurring naturally though- Sure it does. All those beer cans that grow naturally alongside our national parks...That's where aluminum comes from, of course. http://bbs.homeshopmachinist.net//smile.gif
So I think you are right about the big picture, BUT what proves us both wrong, is that they use it all over motorcycles. And, they get subjected to rain, road salt, wear & tear for years. How?
Thanks for the stainless idea, but that is out by reason of weight, machining, cost etc. Too bad; woulda been good.

Thanks all who have provided solutions for the short-term though; it helps.

SJorgensen
02-14-2003, 11:21 PM
Well Revolution,
I only exposed my motorcycle to the same elements that a boat is exposed to once, and I can only tell you that it didn't work out very well for me, or the motorcycle. There are lots of other practical differences, and I think that the most important one is that most motorcycles are kept garaged, or covered, like a good convertable automobile. The ones that look good, are NOT the same, as the ones that are exposed to the elements. In order to see what your part will look like, after two years of exposure to the elements, you have to look in the junk pile BEHIND the motorcycle repair shop. http://bbs.homeshopmachinist.net//cool.gif
Spence

[This message has been edited by SJorgensen (edited 02-14-2003).]

irontoys
02-19-2003, 06:05 PM
<font face="Verdana, Arial" size="2">Originally posted by Revolution:
Hello...I could use a bit of advice on this.

I have a new product here, an automotive/ boat/ RV accessory, that is made of aluminum. I want this item to become and remain hi-gloss mirror shiny.

Anodizing in the usual way is out, since it just won't be good enough.

What I would really like, is if it could be chrome or nickel plated. It would look great, it would offer decent corrosion protection and wear resistance too. And, it doesn't cost a fortune.
BUT I'm fully aware of galvanic issues arising, not leastly since chrome & nickel generally want an underlayer of copper. (Copper & Al don't get along with each other). In fact, I have been told by a plating guy, that he just won't do it, because he knows that it just fizzles in a year or two.
BUT I'm also aware that chrome-plated aluminum turns up all the time on cars & motorcycles. Works fine for them.

Need this for primarily two areas. Now, for display demos in our sales center, where customers will be fidgeting with it constantly.
Then, in the real world, where hard usage and exposure to weather, salt water and other nasties might be a problem.

So, what do I do, then and now? Mirror shine, no corrosion, good wear resistance. Preferably a widespread technology as well; a special treatment available only from NASA won't help much, I'm afraid.

Teflon? Clear coat & oven bake? Chrome? Silver?
Can anyone help me? Thanks all who read this!

Forgot to say that we will be using machined aluminum bar stock, 6061 or maybe something more machine-oriented like Pb109. And that for now, I have no problem at all in doing the initial polishing.

Thanks!</font>
Check with your local custom plating shop.Aluminum can be nickel/chrome plated easily enough if carefully cleaned and a zincate applied prior to plating.Special cleaners are used to prevent smutting. Aluminum will turn black from conventional cleaners (NaOH). The resulting smut is not electrically conductive. Also, you said you will will polish prior to plating. Buffing compounds are usually animal fat based and leave a greasy surface behind. Sometimes precleaning with a solvent is necessary to remove the grease, before immersion in the aluminum cleaner. After rinsing the AL. cleaner, an acid salt dip is used to "activate" the part prior to the zincate step. The zincate process leaves behind a zinc coating on the aluminum. This zincate film will protect the aluminum from dissolving in the nickel plating tank, (pH 3.5-4.0 very acidic) and allow the part to be nickel plated. After a water rinse, trivalent or hexavalent chrome is applied to the nickel to keep it from tarnishing.Manufacturers such as Oakite, Udylite, (Oxy chemical) can supply cleaners and zincate solutions.

Revolution
02-19-2003, 06:28 PM
YES !!! Yeah, man, oh YES!