Feedback PLease; Cup Wheels
04-27-2012, 09:56 PM
#16
Rennlist Member
Crossworth ... sorry .. refinished wheels are for my GTS, and the other set on it now are being swapped onto the 82. Can't help with a code for the paint, but as I mentioned, a good wheel refinisher can eye match your factory colour, just as a good painter can match body colours.
Hacker raises an issue a lot are not aware of ... and should be. You'll notice on the pic of the inside of my wheel there is no paint on the mating surface, and I've removed the paint where the lug nuts seat too ... for a good reason. Paint (or powdercoat) on bearing/mating surfaces gets hot, particularly on wheel/hub faces, and softens and acts as a lubricant. The soft paint allows the wheel to rotate a fraction and hammer the studs and wheel ... the result, particularly under conditions like racing, is to shear the studs, and you lose a wheel. Powdercoating is worse than paint as all seems OK until that first major heat cycle, and then all hell lets loose.
I know a lot paint rotor hats, and get overspray on mating surfaces, and get away with it ... but probably just because they might happen to tighten lug nuts up (or other bolts) before they get too loose. The problem creeps up on you on a road car because of the less severe heat cycles, but in a race environment the first massive heat increase converts the paint to lubricant, and then it's only a matter of time to disaster.
I learned the lesson of what paint on mating/bearing surfaces can do decades ago at high speed ... on a race track ... instant shrapnel ... ouch !!!
If two parts are bolted together don't put a lubricating layer of paint there in the first place, or remove it from mating faces before you bolt them together .... or you risk them coming apart unexpectedly. This applies to all metal to metal contact faces transmitting a load, and not just wheels.
..... This past weekend I was reminded of another reason why, as the wheels came loose on a car running around the track. The powdercoating interfeared with the clearances mating to the hub and even with proper bolt torque......it was almost a very bad situation. Luckily the driver realized something was wrong before the wheel flew off at speed.
I know a lot paint rotor hats, and get overspray on mating surfaces, and get away with it ... but probably just because they might happen to tighten lug nuts up (or other bolts) before they get too loose. The problem creeps up on you on a road car because of the less severe heat cycles, but in a race environment the first massive heat increase converts the paint to lubricant, and then it's only a matter of time to disaster.
I learned the lesson of what paint on mating/bearing surfaces can do decades ago at high speed ... on a race track ... instant shrapnel ... ouch !!!
If two parts are bolted together don't put a lubricating layer of paint there in the first place, or remove it from mating faces before you bolt them together .... or you risk them coming apart unexpectedly. This applies to all metal to metal contact faces transmitting a load, and not just wheels.
