Bill..
Good question about the chrome plated wheels on your GMC pickup. As Bob,
the plater said hydrogen embrittlement doesn't effect mild steel as much
as high carbon steel.
I built my first set of chrome wheels in '59...40 Ford centers with 49
Ply rims for the front, 40 Ford centers with 6" Lincoln rims for the
rear. This was on the 29 Tudor. Never had a problem with the chrome
wheels. However, about 6 months later, the chrome front main leaf
spring broke. Took it to Northwest testing lab and they said it was
from hydrogen embrittlement.
I saw a front tube axle that was broken one time and supposedly it was
from hydrogen embrittlement. I've seen a lot of small springs like
throttle springs break because of it.
I've never seen or heard of a chrome wheel breaking...only the weld
coming apart because of poor welding. Hydrogen emb. doesn't occur at
the weld, it occurs in the base metal.
I think aircraft specs call for plated parts to be baked within one hour
of plating for one hour at 350 degrees and Bob, the plater, has already
told us this. It's good to know we have a plater on our list.
One thing I'll mention here...in today's world the cars have to be made
lighter to comply with govt. gas mileage etc. so parts are being made
lighter. To do this a lot of parts are being made out of different
alloys than years ago. If you use these parts it would be good to find
out what they are made of before you alter them. We have found that a
lot of the aluminum parts have a much higher magnesium content in them.
For over 30 years I built dropped spindles from factory forging ...I
built hundreds of them, had them tested and never had one break.
However, I wouldn't think of cutting and welding one of today's factory
spindles. Most of them are cast steel and heat treated and you don't
know what you're dealing with. Yes, I am sure I will build more chrome
or brass plated wheels, but springs and high carbon steel I would not
plate.
Russ Meeks
RM Engineering/Finishline Coating
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