Early OEM FPS Alloys - What are they made of?

[billy g]

Are they magnesium or aluminum alloy? I've been searching and can't find a definitive answer.  I'm asking because I found a set for decent price, but there are a few minor bends that I should probably have straightened.  I contacted a local wheel shop for a repair estimate and they said they won't do magnesium.  I don't think they're magnesium, but can anyone confirm?

[tech71]

Cant confirm but I doubt  magnesium is the primary metal.

Test it, file off a little from somewhere and see what it does when ignited with a torch.

Local wheel shop sounds none to knowledgable or maybe just trying to blow you off.

If they are not idiots they should be able to check one out and tell you.

[Conserv]

Billy,

 

They’re aluminum alloy: both the originals (1971-1974?) and the re-pops (1999-2021?). You can leave them in the garage for decades and they won’t acquire the corrosion “potholes” common to magnesium alloys. Any wheel shop can and will work on them. I’ve had a bunch straightened. They are not fussy!

 

They were all manufactured by FPS, and I can’t say that I’ve ever seen an FPS-produced magnesium alloy rim. (I make this bold statement just hoping someone will prove me wrong, and show me some gorgeous aftermarket rim that FPS produced in magnesium alloy! 😉)

 

Regards,

 

Steve

 

 

[billy g]

Thanks Steve.  I figured you'd know the answer.  I was 99% sure they were aluminum myself, but some folks out there on the internets (not here) are claiming these are magnesium.  Mine are originals (stamp date September 1972) and show no sign of corrosion or pitting.  Still waiting for an estimate from the shop...

 

Follow up question:  are these safe to have powder coated?

[Conserv]

On 12/14/2022 at 3:59 PM, billy g said:

 

Follow up question:  are these safe to have powder coated?

 

Yes, Billy,

 

The design is largely copied from an earlier Cromodora design, a design that was executed in… magnesium alloy. I’d guess that that might be the basis for some of the misinformation out there. I’ve often seen the early OEM alloys referred to, in sales listings — the kind that advertise ‘02’s with “factory A/C” 🙄 — as Cromodora rims despite; (a.) the absence of the cast-in “Cromodora” and (b.) the presence of the cast-in “FPS”! 🙄
 

Regards,

 

Steve

 

 

[otisdog]

4 hours ago, billy g said:

 

Follow up question:  are these safe to have powder coated?

I have a set of 72's that have been powder coated for40 years, so it is definitely safe,  BUT...... powder coated wheels just don't have the patina of properly painted wheels, which is 'a thing' on these old cars.I f I could do it over again, I wouldn't have powder coated them. Rest assured my set of the later alloys will be painted.

[0257]

Photos?  So I know what wheel we’re talking about!

[stephers]

Cerakote , I think, is the way to go on wheels      Better than powder for longevity and nicer looking than paint     I have done both ways, paint or powder coat, myself, in my own shop but the next set I do , I am going to try doing them with Cerakote air dry 

 

Thanks, Rick

[billy g]

@0257 Here's some photos of my wheels with 'the bends', before I cleaned them up. They actually have a nice patina and I'd consider leaving them as-is if they weren't bent.

 

@otisdog Interesting point about painting versus powder coating. Do you have any photos of your wheels? It would be fun to compare.

[0257]

Love those.  They're not period-correct for my '74, but since I have the Euro bumpers I am constantly tempted to get some anyway.  Best of all 2002 wheels.  Good info on this post.

[billy g]

I have a '74 as well, also with euro bumpers. I actually picked up a nice set of late alloys a couple months ago, but haven't put them on.  I kept pining for the early alloys (I agree they are best) and decided to make it happen despite them not being correct.

[billy g]

6 hours ago, Conserv said:

Yes, Billy,

 

The design is largely copied from an earlier Cromodora design, a design that was executed in… magnesium alloy. I’d guess that that might be the basis for some of the misinformation out there. I’ve often see the early OEM alloys referred to, in sales listings — the kind that advertise ‘02’s with “factory A/C” 🙄 — as Cromodora rims despite; (a.) the absence of the cast-in “Cromodora” and (b.) the presence of the cast-in “FPS”!
 

Regards,

 

Steve

 

 

 

Yes, I've seen eBay listings describing these as magnesium alloys which only adds to the confusion.

 

Can you recommend a RAL color for the powder coat?  My '02 is Polaris and it seems risky to try and match the color. Perhaps a shade of grey would work better?

[Mike Self]

I have one FPS early alloy (per those pictured) that's never been on the ground (must have been a spare) as the lug nut hole tapers have no evidence of scratching.  It's yellowed a bit, which confirms that they originally had clear coat over the silver paint.  

 

I've repainted mine several times, using Krylon "Dull Aluminum" color, the oversprayed with clear.  That combination matches my original wheel perfectly for gloss and color, if you discount the yellowed OEM clear coat.  Dull Aluminum has become very hard to find.  Borden (Krylon maker) says it's still a produced color, but none of my local stores carry it; they used to.  

 

To do those early FPS alloys correctly if you're going for authenticity, they should be primered front and back with a light grey self-etching primer.  Then the front side of the wheel is first painted silver, then followed with clear.  But not the back side.  It remains in primer, with overspray through the vent holes around the edge, plus center hole. 

 

Oddly enough, steel wheels were painted the same way: they came from the wheel maker in black, then were painted silver only on the out-facing side, with the original black (with overspray) on the back side.  

 

Apparently the factory started offering those early alloys when the 2002ti was introduced, as they're not in any of my early accessory catalogs, nor are they pictured in my French language 1970 or so  1600ti sales catalog.  

 

mike

[Conserv]

Mike,

 

Do you mean tii, rather than ti? I believe the early OEM alloys were introduced in early 1971, roughly with the introduction of the touring models. Although tourings were all Modell 71 cars, or later, I believe there was at least one “introductory show example” of the touring prior to April 1971 (photo below), with full Modell 71 trim.

 

So I view the early OEM alloys as the alloy rim option for Modell 71’s (late 1971 through 1973 model years) and the late OEM alloys as the alloy rim option for Modell 73’s (1974 through 1976 model years). 
 

Best regards,

 

Steve

 

 

[JohnS]

15 hours ago, billy g said:

 

Yes, I've seen eBay listings describing these as magnesium alloys which only adds to the confusion.

 

Can you recommend a RAL color for the powder coat?  My '02 is Polaris and it seems risky to try and match the color. Perhaps a shade of grey would work better?

If you want to get a good match to the original color, I would take one of the wheels into Powder Coat It and have them suggest the best match.  I did that with the air filter housing from my tii and they matched it perfectly.  They're in Santa Cruz on the frontage road off of 41st Ave.  That is, if you insist on powder coating the wheels.  I normally go with paint for wheels myself.  Like Mike said 🙂

Edited December 15, 2022 by JohnS