Polished Svx Wheels

[crazyhorse]

I could definately see this on a forged wheel. Such as the JDM BBS wheels

I was thinking ours were cast though. I need to be careful about thinking though, it usually gets me in BIG trouble

[Crazy_pilot]

Originally Posted by crazyhorse

I could definately see this on a forged wheel. Such as the JDM BBS wheels

I was thinking ours were cast though. I need to be careful about thinking though, it usually gets me in BIG trouble

Ya, me too...

I actually looked up the temperatures and times needed to bake powdercoating, and then what's needed to temper forged alloys. I can't remember the numbers off hand, but the end result was that the powdercoat baking process is neither hot enough, nor long enough to significantly affect the molecular structure of an alloy wheel. Tempering is done several hundred degrees hotter (like 600 F for tempering vs 400 for coating), and takes longer than the baking does.

If I ever wanted to re-do my forged BBS rims and had the money, I wouldn't hesitate to powdercoat them.

[Djsvxxl]

Originally Posted by 94SubieSVX

Just get it done professionally

I'am a professional

or at least I'm working with one.
still like the painting over the powder coating

[RallyBob]

FWIW, I have seen firsthand the result of powdercoating a forged BBS (STI) wheel, and it wasn't pretty. Keeping in mind that different brands and colors of powdercoat have different curing temps, (350-500° F), there is sufficient heat to anneal aluminum. It basically makes the wheel very soft by removing the heat-treatment, and at that point the wheel is more succeptible to bending (but ironically resists breakage more readily). For comparison, I anneal copper gaskets by heating to 350° for 30 minutes, and it makes it dead-soft.

Even cast wheels will be affected at higher temps. It depends a lot on the alloy used however. Higher grade wheels are generally more easily affected from what I've seen, at least in terms of reduction percentage of strength compared to OEM, since they are normally heat treated to higher specification.

Another issue is that it is fairly common practice for powdercoaters to bake a wheel at extended high temps (550°) to aid in removal of factory paint and powdercoat prior to beadblasting. This particular process is usually the culprit, rather than the curing process. If the wheel is polished and is being prepared for clearcoat, this is often the only option, since bead blasting would damage the polished surface. The surface of the wheel must be 'clean-clean' to avoid outgassing during the curing process, since there will likely be residual paint, oils, brake dust, and polishing compounds imbedded in the aluminum's surface.

HTH,

[Djsvxxl]

OK... so I'm gonna paint them with clear