VCCA Home Forums TECHNICAL - GENERAL Body - Sheet Metal, Paint & Wood Stainless Steel trim that…s pitted???

Well I’ve been working around metal all of my life, me Pop was a metal worker and me brother also and we’ve had fabrication shops and I worked till my retirement as a fabricator, welder and inspector at a government accelerator lab where 90% of everything is SS, much of it exposed to the elements.
I was over at my buddy’s garage today and we were looking at the bowtie/Chevrolet hood emblem on his ’50. I noticed it was all full of pits like you would see on a chromed part and that’s what I though it was. He said, “oh no, that’s stainless.” So I sayz, “oh no mon ami, stainless don’t pit like that.” So of course we both reach for the magnet and guess what, it’s stainless!
Now that’s a first for me, never saw any that did that and I just can’t figure what would cause that.
Denny Graham
Sandwich, IL

Salt,low pH and elevated temps.

Denny,

I could be mistaken (it has happened on occasion)but I believe the hood emblem on the 50s was chrome plated pot metal (a zinc alloy?) and a magnet won't take to it. The front hood emblem, the side hood emblems and the hood ornament on my 48 are all chromed pot metal.....and all pitted so bad I had to replace all of them. 50s could be different.

Just my opinion for what its worth.

Are you sure it was stainless? I belive that through the years there was a stainless (probably in the later years) and a stamped steel (chrome plated). When the chrome plating got to be a problem because of the Korean was they went to stainless. The early version was pot metal. The '52 I had had a steel/chrome plated (chrome was peeling) and I replaced it with a used stainless (not plated) and it was still nice and shiney.

His and mine are both 50's, his a 3100, and mine a 3600. My emblum looks like brand new and with out taking it off I would say that it was SS. If you tap it it sounds hollow and I can see what looks like drag marks from the die on the edges where there are sharp bends. I can't see far enough behind the piece to tell if it's solid or not, it just looks like sheet metal that has been wrapped around under the piece. I taint saying that they aren't die castings, very well could be. And the pitting condition on his is exactly what I would expect from a chrome plated die casting. Only way to tell would be to pull one off but the four clutch head screws that hold them on are at a bad angle to get at, so I'm not gonna pull mine off right now.
I thought with all the experiance here at the VCCA that there might be someone that has has the trim off their AD hood for painting. I'm not at that point yet. I am also looking for an answer over at the stovebolt also.
Denny Graham
Sandwich, IL

Well I just went out and took a good long look at the back side and it looks like I would have to take the stiffener off the inside front of the hood in order to get at the trim screws. And I surely taint gonna do that tonight.
DG

The term used for stainless steel in the Aerospace industry is Cres. corrosion resistant steel.

Different Cres has different properties depending on the amount of alloying element in the mixture.
The three main types are Austenic, martensitic and ferritic.
They all have different uses, some are magnetic, others are not , some are used for surgical instruments due to keeping a sharp edge, Austenitic is the most common used in Aircraft engine parts.(it doesnt interfere with aircraft navigation compasses as well)

18 / 8 (18% chromium, 8% nickel)is a common CRES used in house hold knives and forks.

Yes , Stainless steel does pit, i bought some 1948 wheel trims which had been sitting outside for 30 years and they have pitting fom numerous rust spots which were removed with emerycloth and wet/dry.

I had, may still have, some NOS 1956 Chevy mouldings that were pitted. I think I gave some to a friend who was building a "Driver". He was glad to get them but I always wondered what the deal was.

Mike

Sounds like your buddy has the chromed pot metal front badge.
No need to remove the upper hood support to get at the hood badge clutchhead screws.
All you need is a small 1/4" drive ratcheting screw driver with the correct clutchhead driver.