How do I know if I have magnesium rims?

Two tests:

pick it up, if it is lighter than 10 lbs, you got magnesium

Or,

Light a match to it. If it burns, you have magnesium.

 

I think magnesium was OEM spec for all years, no?

 

It's a "high content alloy" on the road wheels......

Ferrari has never made a pure magnesium alloy wheel for the street.

That said, the rules of "refinishing aerospace alloy castings" apply to the "early wheels" and all of the 14"s definately fall under that guideline.

Sand it lightly and paint the damn thing.
Stripping it totally, as they would a modern wheel is a hugely bad idea.
Leave the Factory primers alone and you are golden.

 

Lighting a match to it wouldn't work. Taking a blade to it and putting a flame to some small shavings could if they contain really high magnesium content.

 

The alloy content of Ferrari road wheels is published.

It's not that high (to burn) IIRC.

 

what mg 308 was ever 10lbs or lighter?

wont burn with a match... only the powdery stuff will ignite

 

None

I know that someone previously posted the weights of the stock 16" 308 wheels vs the 16" KN reproductions (from which the estimated Mg content of the stock wheels was on the order of ~30% Mg) -- but I can't find that thread!

 

"light alloy" was the OEM spec for all stock 308 wheels.

 

I thought the test was to sand a spot on the back to the bare metal and pour vinegar on it. If it foams its magnesium.

 

Take look at the back of the wheel. There is "Magnesio" cast into it. Most Cromodora and Campagnolo wheels have Magnesium content in the alloy. I agree with Big Tex, sand them and paint them. Best way as they can be repaired if you scratch them again.

 

If you have bad enough curb rash that it needs repairing, use the same body filler you would on any other part of the car. When I bought a wheel repair kit I was surprised to see that this was the solution to curb rash.

Worked on my M roadster wheels quite nicely.

D

 

Agree on that also, polyester body filler evens out the minor chips and tool marks.

 

Call Bill and Tom at Maranello Motorworks. They can put you in touch with a qualified person in Colorado

 

How to test for magnesium.

First a quote from the web:

"The rear engine hydroplane "Skip-A-Long" powered by a 2000hp Allison...built in 1948. After winning 4 out of 5 races in 1949 it sank in 469' of water during an exhibition race at the Lake Tahoe Yacht Club Regatta. The technology needed to raise the sunken craft did not exist in 1949, so it remained in a watery grave for many decades until it was raised in 1984..."

I saw the boat shortly after it was raised from the very pure fresh water of Lake Tahoe.

The aluminum hull and the aluminum engine were almost in perfect condition.

The intake manifold was missing. It was made of magnesium and was eaten by the very pure water.

So place your wheels in Lake Tahoe and see if they are there 35 years later. If not, they were made of magnesium.

 

Just look for the word "MAGNESIO" cast into the back of the wheel...?

 

My '85 308QV 16" wheels have them.

 

Here is a great website resource for restoring magnesium wheels - done by a ferrari guy doing his Cromodora Dino wheels. I am in the process of restoring my BBS center castings.

https://stevekouracos.com/restoration/tips-and-tricks/aluminum-magnesium-wheel-restoration/

 

What is the Michelin tire you have? thanks.

 

Congrats on finding somebody! Your finished wheels look great!!!

I finally just got my BBS's out to paint. Somebody had the genius idea to powder coat the wheels. If you thought stripping paint off magnesium was difficult, powder coat is like 50x harder. Wound up going through a special chemical stripping process and then sand blasted for the first time, walnut very ineffectively and then moved to glass. I will post in my own thread with pictures and details.