wheel restoration: paint or powder coat?

[joebarthlow]

I picked us a set of these BMW wheels. I believe they came off an E21. Can someone ID years of use?

 

Also, as you can see they are a bit knackered, so I plan to restore them. I understand the possible set back issues, but I plan to run 175s

 

Question: should I powder coat or paint?

 

Can I achieve the right silver with powder coating?

 

If I paint, I should clear coat?

 

thanks

 

 

Edited December 10, 2017 by joebarthlow

[Mike Self]

While powder coating is more durable, it's also more difficult to repair when chipped, which is easy to do when mounting tires or balancing 'em. 

 

You can get very close to the factory silver on '02, E21 and E30 wheels--steel and alloy--with Krylon "Dull Aluminum" spray paint followed by Krylon "Clear acrylic"  It'll last 4-5 + years if you don't drive in the salt. 

 

BTW, using 175/70x13 tires will throw your speedometer/odometer readings off, as it's smaller in diameter than the OEM 165/80 or more commonly used 185/70 x13.  Both of these have almost identical rolling diameters.

 

mike

[PaulTWinterton]

40 minutes ago, mike said:

BTW, using 175/70x13 tires will throw your speedometer/odometer readings off, as it's smaller in diameter than the OEM 165/80 or more commonly used 185/70 x13.  Both of these have almost identical rolling diameters.

 

3% off.  The 70 sidewall height gives the tire a 3% smaller (rolling) circumference vs the 80 sidewall that the gauges are calibrated on.  Therefore, on the road, the car travels 3% less/slower than the odometer/speedometer reads.

Edited December 10, 2017 by PaulTWinterton

[joebarthlow]

2 hours ago, mike said:

While powder coating is more durable, it's also more difficult to repair when chipped, which is easy to do when mounting tires or balancing 'em. 

 

You can get very close to the factory silver on '02, E21 and E30 wheels--steel and alloy--with Krylon "Dull Aluminum" spray paint followed by Krylon "Clear acrylic"  It'll last 4-5 + years if you don't drive in the salt. 

 

BTW, using 175/70x13 tires will throw your speedometer/odometer readings off, as it's smaller in diameter than the OEM 165/80 or more commonly used 185/70 x13.  Both of these have almost identical rolling diameters.

 

mike

 

good idea on the paint. I'm running 185/70 13 already and my speedo is off 6 mph (at 60)

Edited December 11, 2017 by joebarthlow

[Conserv]

Joe,

 

Probably 1977-ish through 198?

 

Individual rims are virtually always dated, either month and year or week and year.  The date is generally on the face but occasionally on the reverse.  If you provide a good close-up, we can probably help you.

 

As to finishes, I do both.  I find the powdercoating (a.) is much more durable, but (b.) often obscures stamped-in or cast-in markings.  And...I’ve not yet found the perfect RAL color for powdercoating.

 

Best regards,

 

Steve

 

[Dick R]

Here's a handy source of tire dimensions I found that can be used to calculate the differences between whatever size tires you are comparing.  For the effect on speedometer readings, just use the rightmost column which is revs per mile.  For example, the 165/80R13 shows 862 revs per mile and the 175/70R13 is 891 revs per mile.  Like the previous poster says for these sizes, that means the 175/70 tires would spin about 3% faster (as would the engine) with the speedometer showing the same 3% positive discrepancy.   (For the record the actual calculation comes out to 3.4%.) 

 

http://www.tyresizecalculator.com/charts/tire-size-chart-metric-by-rim-wheel-diameter

 

 

[John_in_VA]

There are almost too many powder coat silver options, but I wouldn't spend it on those wheels (no offense!).  The Dull Aluminum/Clear option mike mentioned is a nice look.  You or your painter could use an approximation of BMW's Polaris for a good look, too.

[Conserv]

1 hour ago, John_in_VA said:

.....You or your painter could use an approximation of BMW's Polaris for a good look, too.

 

But just to be clear, John, Krylon’s dull aluminum is probably a better match for the original color.   Having spent 41 years with a Polaris ‘02, the mis-match between the Polaris body and the “whatever color” rims has bugged me for...41 years.

 

But yes, on its own, Polaris would be a great color for rims!

 

Best regards,

 

Steve

 

[jp5Touring]

If your looking for a original look I would just paint them.

As far as powder coating  I've had great luck,my wheels are three years old and still look new.

 

 

[joebarthlow]

5 hours ago, Conserv said:

 

 

But yes, on its own, Polaris would be a great color for rims!

 

Best regards,

 

Steve

 

 

that is a thought since I need to paint the some lower sections. either way they will be silver

[thinksound_mike]

I painted similar wheels with VHT Silver Caliper Paint. It's made to withstand higher temps so it should be more durable. I used a matte clear over it, 2-3 coats.

 

[Mark92131]

The centers on those 320i rims are normally painted a darker grey.  The Dull Aluminum + Clear Coat on the spokes is very close to the original finish.

 

Mark92131

 

 

[joebarthlow]

33 minutes ago, Mark92131 said:

The centers on those 320i rims are normally painted a darker grey.  The Dull Aluminum + Clear Coat on the spokes is very close to the original finish.

 

Mark92131

 

 

 

that's my plan. what tires are you running? 

 

[EuroTech]

Not to hi-jack but I have same wheels and was contemplating the same thing... powder coat vs paint.... but I was under the impression the turbine e21 wheels you have are aluminum... I was under the understanding that powdercoating aluminum wheels can cause cracked/warped wheels due to the powder coating cure cooking time of usually 400*f for 15mins...does anyone know if that’s true or has anyone had long history with powder coated aluminum wheels? Thanks


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[Conserv]

I suspect, but don’t know for a fact, that most alloy rims today are aluminum alloy.  I’ve had many alloy rims powdercoated, rims dating from the late 1960’s to 2014, and I haven’t heard this warning...yet.

 

Also having an affection for period magnesium alloy rims, I’ve both long heard this warning with respect to such rims, and long promulgated said warning with respect to magnesium alloy rims.

 

I don’t dismiss any warning that suggests 400 degrees could have a harmful effect on such an important component as a car’s rims, but I’m eager to know whether this warning has credibility among people who know more metallurgy and physics than I — which would probably be most people....

 

Best regards,

 

Steve

 

 

 

Edited December 12, 2017 by Conserv