Cromadora Wheel Restoration

[alfacybersite <acs@domain.elided>]

Regarding Cromodora / magnesium rims turning to sugar after a number of
years, I have to give a qualified 'hog-wash'.

The qualified part is because I'm not a metallurgist and I live in So.
Cal. where we don't put salt on our roads. I notice Dave Hammond is from
Detroit, where I know full well they use salt (apparently in abundance)
during the Winter.

My gut feeling, which I shared yesterday with a friend / engineer /
major wheel junky, is as stated, hog-wash. He, to put it mildly, agreed.

We both agreed that if a magnesium rim has been properly cared for and
not abused (racing with them probably qualifies as abuse), age was
virtually a non-factor.

I was tempted to email Dave and suggest if he would have a brand new
Alfetta (98 mmalas, NLA) Cromodora 5-star standing by, I'd agree to
have one of my 21 year old rims tested. If it spec'd within 10% of
original tests on new 5-stars, I get the new mythical rim.

That said, my same friend told of a car he bought in Michigan (is it
really the salt capital of the world?) about 30 years ago. When he
removed the steel backed lead weights from the rims everything behind,
did in fact, turn to powdered sugar. He had them repaired and still has
them and the car.

I just semi-installed one of my recently painted rims (or wheelssince
there is now a tire on it) on the car to see if the additional primer /
paint / clear-coat which I also used in the center hubs would make it
difficult or impossible to install on the hubs. A tiny push, but they go
on fine.

Yes, these rims had some powdered sugar on the inside of the hubs which
I ground down to bare, solid, metal. Little metal was lost.

I agree, in case of doubt, have bead blasted. This should show up any
and all flaws. I hate to do it because I love the sharp, raised
lettering on the Cromodoras and it will get slightly rounded off. But
you will have piece of mind.

Terribly unscientific, but I'd then take each bare, naked rim and
holding it flat, drop it onto a concrete floor from about a 1/2" height.
If it rings true, I'd be satisfiedthough other's might not. Or gently
tap it with a small hammer, but the dropping it flat will give a better
indication.

My rims have a small 81 in the back with a dot on the 5th box of 12. I'd
say it's safe to say they were made in May of '81.

While I've not harped on the safety factor of properly preserving,
especially magnesium rims, this is no doubt a more important reason for
not putting on a coat or two of spray can paint and assuming you've just
restored your rims.

I've never clear-coated a car and I've never Not clear (or dull) coated
rims.

Biba
Irwindale, CA USA

I charge around $300 for prepping (includes only minor repair) and
painting a set of 4 rims. My cost, excluding labor, is approximately $48
per rim. Not a get rich proposition.

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