Restoring Aluminium

[den912]

Been looking at getting the window frames of our car restored ,one way of having them done is using Chromium Plating ,has anyone else used this method .My only concern is that it adds to the thickness of the parts and makes them hard to refit
Thanks Brian

[safe]

Polish them and send away to be re-anodized clear. Might be cheaper to just buy new ones.

[AG81]

Plating is certainly going to add thickness.... usually .005 to .01 thickness. I don't know about that causing them to be difficult to be refit. They are a PITA regardless for me.

[1QuickS]

67 & earlier frames were brass with chrome plating. 68 and later are aluminum and were anodized. To polish aluminum frames you must first remove the anodizing. Your anodizer can do that for you or you can do it at home with drain cleaner (I think). Caswell.com has lots of products to help with many restoration projects regarding plating & polishing. The chrome frames must be stripped to brass and them re-plated.

I used aluminum frames from a 68 on my 67 hot rod. I stripped the anodizing & polished until they looked like chrome. They then needed routine maintenance with "Mother's" aluminum polish to keep them looking like chrome.

[Robert Adams]

The process I used with my bumper deco trim would probably be the same for window trim. I will be doing my front & rear window trim once I see how the bumper process works out. The person who polished my cookies is now striping and polishing the bumper parts. They used an aluminum oxide media to clean the aluminum parts and a little more aggressive treatment to the dings; then polishing them. I'm getting the bumper deco trim back from the polisher within the next couple days so we'll see. I found a shop in FL that will 'bright dip anodize' the parts which is Porsche's original finish. I have to admit just leaving them polished is tempting; they will look like jewelry if they come back looking like the wheels. The process is definitely cheaper than buying new deco parts or a really nice original pair, but windshield trim probably isn't cheaper than buying new. On the other hand, from what I have seen and by other people's accounts, reproduction parts aren't always completely true to Porsche's original part in measurements or quality.
The cost to strip & polish is $185 for both rear deco's. My front deco happens to look like new thankfully. The bright dip is $200 for both, plus shipping.
I can post before and after once I get there if there is any interest? ….and will gladly pass on the fellow's info doing the anodizing if this all works out as anticipated. I also know someone in the Midwest that is slightly more expensive that does a turnkey; the stripping, polishing and handles the bright dip anodizing through a another party included in his fee. I have no first hand knowledge, but came highly recommended.

[911pcars]

The usual process to restore the trimwork is to polish to remove all blems, then anodize or otherwise coat the base material. Most shops charge a premium for this.

I have trimwork that was powder coated black many, many years ago. While powder is a relatively thick coating, it worked and lasted a lot longer than the typical anodized black applied by the factory.

One alternative I will try next is ceramic coating. Typically, .001-.003" coating thickness (versus powder at ~.006"), durable and resists typical automotive solvents and lubes (including brake fluid). In addition, since it's a coating, surfaces can be prepped with body filler and/or primer, then coated. The coating colors are numerous, including aluminum, stainless steel and chrome.

https://www.cerakote.com/resources/files/Cerakote%20Color%20Chart%20WEB.pdf

Surface prep:
07 Surface Preparation and Priming for Ceramic Coating: - Deep Energy Solutions

Sherwood
(no affiliation)

[Shaun @ Tru6]

You have to have a pretty big oven if you want to use Cerakote.










Black anodizing








Clear anodizing

[panzerfaust]

some fantastic work there Shaun

[Geronimo '74]

Those clears are very nice!
Been thinking about backdating those on my 86 (black and faded)
Frames and headlightrings
And bezels in the windowseals

[Shaun @ Tru6]

Thank you Gentlemen, window frames are my favorite things to restore. No matter which process, each set takes a week from start to finish. The Cerakote frames are shot and baked 3 times to get a perfect, extremely durable finish.

Ger, you will need to find a set of earlier frames if you want to polish and clear anodize them. I'm not sure when but at some point Porsche started to use a softer, cheaper, more porous aluminum alloy for the painted frames and it can't be anodized (with good results anyway).

[Geronimo '74]

Good tip, thanks!

[Trackrash]

Amazing work.

I was told by a plater, when I had some of my trim done, that Porsche used a "bright finish". I notice your window trim is much more shiny than say the anodizing on Fuchs. Comments?

[Shaun @ Tru6]

Porsche original used a technique called bright dip and then clear anodize. Bright dip is basically 2 different acids, one sits in the valleys of a "rough" surface and the other acid eats away the peaks. A polished surface is nothing more than a smooth surface that more directly reflects light which creates shine.

Because of the nature of the acid chemistry, most anodizers don't do bright dip anymore. The acids are particularly nasty from what I understand.

If you've ever picked up a set of 65-67 chromed brass frames you'll know why Porsche went to aluminum. Brass frames are very heavy. Also cost a lot more to produce than aluminum.

While Porsche could have just done a very simple satin aluminum frame, they wanted to keep the look of chrome so they used the bright dip process to brighten and then anodize the frames for 68 onward.

When I restore a set of frames the old anodizing is stripped off leaving bare aluminum filled with pits and gouges and scratches and scrapes. Those have to be sanded out, though not every imperfection can be removed, some are so deep you would compromise the profile integrity of the frame removing them. Even average imperfections you are still blending over the entire lenght of the frame. I've gotten frames that were done by "professionals" that removed imperfections locally with a buffing wheel and aggressive compound making them wavy. Sometimes you can save the frame by blocking it down, most times you have the customer get a new frame set.

Fuchs anodizing looks different because the wheels are etched prior to anodizing and they use a different anodizing and a different time in the bath. I use 5 different types of anodizing and prep and timing and what not to get the proper finish.