Tiny cracks in 67 Eldorado wheels?

[67_Eldo]

I am having the wheels on my 1967 Eldorado sandblasted and painted. When I bought them (cleaned up but with the original paint), they looked fine. But when the shop blasted them and inspected them, the shop guys found (in every wheel) little cracks around at least half of the rivets that hold the center piece to the rim. So the shop welded everything up to be nice and crack-less.

Is this a common problem with old Eldorado wheels?

Do they develop hairline cracks around the rivets that hold them together?

Is welding the best solution?

[Mike Josephic CLC #3877]

What kind of tires are you running -- bias ply or radials?

Keep in mind that these early wheels were not designed for radials.
Radials were not even offered as an option until 1972.  Radials will
have more sidewall flex than bias ply tires and will transfer that lateral
force to the wheel.  That could have been your initial problem.

As far as welding them up, I really don't know if that's a lasting fix
or not.  However, the later wheels were welded, not riveted.  The
wheels on my '73 Eldo are welded (that's how they came from the factory).

Mike

[Glen]

Strange.  The wheels on my 68 ELDO do not show any cracks and it has over 300,000 miles on it and I have a heavy foot, meaning the car was not babied.  I have not had them sand blasted so maybe they are cracked, but after all that time and miles, I would not worry about it.   
I’m skeptical about the radial tires adding more stress on the wheels. 

[67_Eldo]

I bought these wheels separately so I don't know their history. Once the repaired wheels are swapped with the ones that are currently on the car (running old bias-ply tires), I'll be able to compare.

I washed up and wire brushed the cracked wheels before they had been sandblasted and they looked good. It wasn't until the sandblasting removed the original paint that the cracks were visible. They were hairline cracks that you could see and feel with your fingernail. None of them were big and obvious. A thick coating of new paint may have covered them up again.

But if there's stress there, they might as well be welded.

[bcroe]

Sounds like fatigue.  I have welded such things on a frame.  But on a critical
and easily swapped thing like a rim, I'd junk them and get newer welded rims. 
Could have been an early design defect.  good luck, Bruce Roe

[67_Eldo]

Perhaps the fatigue problem is why the later wheels were welded instead of riveted? I always figured it would be cheaper to weld than to rivet, but I'm not manufacturing wheels for GM.

I just discovered another interesting, possibly related tidbit on an Airstream forum. I had never heard that Eldorado/Toronado wheels were so delicate. They were discussing the differences between the production Toronado/Eldorado and the GMC Motorhome when this comment popped up.

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"My suspicion is that they found it difficult to find 15" tires with sufficient weight carrying capacity, and those Toronado/Eldorado wheels are a known design issue as they can be easily bent by just barely rubbing a curb . . . one of the most difficult parts to find when refurbishing a 1966-1978 Eldorado/Toronado is a set of five OEM wheels that aren't bent or otherwise out-of-true . . . . I looked for four years and had to give up and have six of the best salvage yard wheels that I could find restored to a degree of trueness that the tires wouldn't prematurely wear on my Toronado."
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Hmmm.