Aluminium Alloy caliper finish

Edited by Jezztor, 27 August 2009 - 13:26.

I have a set of AP Racing CP5100s which have an Aluminium Alloy monobloc body. They were originally powdercoated with a terribly thin layer which has now oxidised. I want to get them refinished. I have been in touch with AP Racing but while I await a response, I thought I'd throw it out here.

Does anyone know what coating typical Al Alloy calipers have? Most of the Wilwood and Brembo calipers that come as OE on production cars are powdercoated with PTFE, but I believe most of the new AP Racing calipers are anodized.

Does anyone know?

Edited by Jezztor, 27 August 2009 - 10:43.

Caliper seals are a consumable item. You are supposed to throw them away. The harder you use them the more often you replace them.

Do you re-use your oil filters?

Edited by Jezztor, 27 August 2009 - 11:27.

I've looked on ebay for the hand of a surgeon, but the nearest I can get is some long-nosed pliers...

I don't know your intended usage but I would never powder coat a caliper because of the heat it would retain.

Get them anodised.

Would it make a significant difference?

This works and looks better than standard powdercoat and you can do it yourself without caliper disassembly:

Would it make a significant difference?

Not to a road car, but having driven some rally cars for long periods of time down steep mountains and having the pedal start to go soft i wouldnt do it.

But also i have never cared really what a car looks like for those type of detailed items (not that i don't appreciate looking at other peoples especially a good Hot Rod), only what it does.

This works and looks better than standard powdercoat and you can do it yourself without caliper disassembly:

http://www.eastwood....per-paints.html

I am not so sure that ap cp5100 do indeed have dust seals.. usually racing calipers only have normal o rings on the pistons, not the outer dust seal, which means they require maintenance and seal changes much more often..

Not to a road car, but having driven some rally cars for long periods of time down steep mountains and having the pedal start to go soft i wouldnt do it.

It was really a rhetorical question, but never mind. If I'd said it doesn't make much difference an expert would have said 'Yes it does!'

No We wouldn't!!

Yes you would, you know you would, especially you Cheapy...

Pistols at Dawn scoundrel!

I'm up for it! Who shall we shoot?

Maybe a stupid question but if somebody sells the calipers in your country why can't they get the seals? I would think AP could post seals to you, have you contacted them at all?
Surprised the calipers have dust seals, any caliper with them I have used in competition just burns the dust seals, maybe AP have a special heat resistant version?

Edited by Jezztor, 29 August 2009 - 09:35.

Having just learned what is involved in anodizing, and since I know what goes on in powdercoating, I'd say don't let the callipers near either process until you have a complete set of service parts for them. They're /brakes/ FFS.

Edited by Canuck, 30 August 2009 - 17:44.

They came back from the powdercoaters in wrinkle black and a quick trip through the manual mill restored the machined Brembo logos.

Having just learned what is involved in anodizing, and since I know what goes on in powdercoating, I'd say don't let the callipers near either process until you have a complete set of service parts for them. They're /brakes/ FFS.

I had a similar issue with some Brembo calipers on a build. The Brembo dealer wouldn't supply a seal kit, ostensibly because we shouldn't have been taking them apart (so they told me).

Caliper seals are a consumable item.....

Do you re-use your condoms?

To be powder-coated, or re coated, they will need to be blast-cleaned, which the coating company can do - usually - but I would be a little nervous of a coating company blast-cleaning something like calipers unless they know exactly what they are doing.

fixed.

Depending on how used they are, I would be rather leery in general about powdercoating used aluminum brake calipers. They have been very hot while exposed to miles of road dirt, grunge, brake dust, dead bugs, road kill, grunge, brake fluid, and grunge. They are probably going to require extra precuring to outgas all the accumulated crud and oils, or otherwise the powdercoat will just bubble and lift anyway and you have spent a lot of $$$ and trouble for nothing. Now, if you are not performing the powdercoating yourself, you can ask for extra precuring and the guy at the counter will say, "Sure thing, buddy, will do," then immediately erase it from his memory. May as well just hit it with some good high-temp header or caliper paint. Looks just fine unless you are gunning for the Ridler Award; easily touched up.

That sounds cool, but even for street use I would expect the wrinkle finish to pick up - and hold - a load of dust. Does it?

This raises an interesting question - is sandblasting not adequate to remove said grunge, brake dust, bugs and grunge? I've only ever sandblasted & powdercoated subframes and miscellaneous components that aren't exposed to such high operating temps.

Of course being the kind of owner that cleans his bike with a toothbrush doesn't hurt either.

Depends what you mean by sandblasting - you want the least-abrasive medium that will do the job, but the Most Important Thing is, as Cheapy's tale confirmed, to make sure no medium gets inside. One tiny bit of grit could be fairly expensive.

Paasche make a neat little detail blast-cleaner -

Thony, I thidn't know you fave a lisp

Granulated walnut hulls.

Firstly, the car is 95% of the time a daily driven at sensible speeds, so nothing like competition conditions experienced.

Edited by Tony Matthews, 02 September 2009 - 16:42.

Please don't resuse old caliper seals.
Please don't blast aluminum racing calipers with abrasive media of any kind.

There, my moral obligation is met. Please feel free to go out and kill yourselves and others.

A tad dramatic I would say there, my good McGuire. You suggested powdercoating is a bad idea in case grime is not lifted from the raw aluminium and the paint bubbles off - how exactly is that jeopardising lives..?

I never said it was. What I said: Please don't reuse old caliper seals. Also, please do not employ any form of abrasive media blasting on aluminum racing calipers. But at the end of the day you can do as you like. It's your car. I've seen people get away with far worse. I just wanted to weigh in on these two matters because both are well known for rising up and biting people right on the ass.

I've scanned over previous posts and I can't find another explanation for the warning against media-blasting aside from bubbling paint and getting media inside the actual caliper should it not be plugged adequately. I am genuinely interested to learn why you are so against media blasting aluminium calipers. I have seen it done to 20 or 25 sets of similar calipers without any catastrophic results. Naturally I'd like to avoid any myself and thus am receptive to any justified opinions.

Is there any good engineering reason to ever paint, anodize or surface coat an Al-alloy caliper? Not having to use anti-seize for steel fasteners?