how do you know if metal's clearcoated?

[chris0626]

In our work on turning this '70 Karmann Ghia into a JagGhia [BTW, for those who haven't seen the pix of this vampiric transformation, you can see them here ] we're picking up lots of parts from junkyards ... errrr ... I mean auto salvage yards. Most need some serious rehab/polishing. I have many metal-cleaning/polishing products on hand. But a lot of them are only to be used on either "clearcoated" or "non-clearcoated" metal. Is there some relatively-simple way for me to know whether the part I have in hand is clearcoated or not? (BTW, I'm not talking about big parts like wheels; I'm talking about small parts -- door handles, antenna parts, and other small attachments.)



I feel like surely this is a stupid question, especially considering how long I've been in Autopia. So, ... although I thoroughly expect somebody to remind me that "The Search Engine is My Friend," I hope you'll go easy on me.

 

[Brad B]

That is a good question, Lynn. It's hard to tell. But, I will bet that none of the bright metal parts on the Ghia, er JagGhia, are coated.



You need a buffer or a grinder with a polishing wheel attachment and some assorted rouges. White and red are what I use 90% of the time. This is the ONLY way to clean/polish/recondition stainless steel, aluminum and chrome.:up

 

[shaf]

I agree, I think this IS a very good question, and I don't know the answer either. I think somebody said you just try using some metal polish on an inconspicous area and see if it turns blue or something?



Fortunately for me I have only occasionally run across any "brightwork".

 

[imported_memnuts]

Lynn, you might try detecting any form of oxidation. This may be difficult if the parts are dirty and may need to be cleaned and allow to dry completely. This will probably only work for aluminum parts. Normally stainless oxidation can be denoted by gross inspection - rust. Wipe the cleaned and dried aluminum parts with a white rug and note if any greyish residue. Hope this helps a little.

 

[imported_mirrorfinishman]

Lynn,



At the very least, you could use a magnet to help you determine what type of metal you are dealing with.



A magnet will be attracted to most metals that contain steel and not attracted to aluminum.

 

[chris0626]

It's hard to tell. But, I will bet that none of the bright metal parts on the Ghia, er JagGhia, are coated.

Agreed. But the deal is, we're pulling parts off much newer cars for tiny little fittings -- e.g., just this weekend, needing the metal "surround" piece for the Ghia, we found a comparable metal piece from a salvaged '90s Honda, which fit. Knowing how cheap car-makers got, I'm running on the assumption that it's some sort of cheap metal that's clear-coated to give it a shine ... but ... :nixweiss

You need a buffer or a grinder with a polishing wheel attachment and some assorted rouges. White and red are what I use 90% of the time. This is the ONLY way to clean/polish/recondition stainless steel, aluminum and chrome.:up

Oh super. More power tools to buy.

Lynn, you might try detecting any form of oxidation. This may be difficult if the parts are dirty and may need to be cleaned and allow to dry completely. This will probably only work for aluminum parts. Normally stainless oxidation can be denoted by gross inspection - rust. Wipe the cleaned and dried aluminum parts with a white rug and note if any greyish residue. Hope this helps a little.

OK. I must be REALLY obtuse, blkZ28Conv -- But are you saying that chrome won't oxidize, whereas other metals and metal-finishes will? I guess I'm really confused as to what's the base metal (aluminum, stainless steel, etc.) and what's the finish (e.g., chrome-plating, clearcoating, etc.) and how all that affects our polishing. :nixweiss

And, yep, I do begin by cleaning all these parts with a car wash soap or APC (depending on extent of filth). I'm just confused about how to "ID" the metal/finish after it's clean.

At the very least, you could use a magnet to help you determine what type of metal you are dealing with. A magnet will be attracted to most metals that contain steel and not attracted to aluminum.

But, mirrorfinishman, like I said above, does the type of base metal determine the finish? or are those unrelated?



Or, .... am I just making too much of this? I've read and heard that certain metal polishes are more aggressive than others, and that you thus need to use the "correct" polish for the finish. But maybe I can just grab my gentlest polish -- regardless of whether I know what type it is or what finish it has -- and work upwards on abrasiveness in the typical Autopian fashion? :nixweiss



I guess if I would just "get with the program" and buy new cars, this wouldn't be a problem for me. I could just rest assured that all the parts were made of recycyled milk cartons, and go from there.