48 replies to this topic

[Jezztor]

I have a set of AP Racing CP5100s which have an Aluminium Alloy 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 - 13:26.

[kikiturbo2]

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?

my wilwoods are anodized.. while my brembos have been powercoated.. I'd say it is easiest for you to powdercoat them..

[Tony Matthews]

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. I haven't had any automotive parts coated as yet, but several pieces of furniture, and I'm waiting for some aluminium castings at this moment! It was pointed out to me that if they found any porosity they would have to heat the castings to avoid the coating being blown out, I said that was OK as long as it wasn't over 660 C, but I was reasured with 'Nah, only about 280.' You, of course, won't suffer from porosity!

I am no expert on coatings, but my gut feeling is than anodizing is easily scratched, whereas powder coating resists scratching but can chip. Both look nice...!

[Jezztor]

Thanks for the replies.

I think by virtue of the wide range of colours available at my powdercoaters, I'll land up going with that. The calipers are originally black with yellow writing, I think I'm going to go with a gunmetal colour with yellow writing to imitate the LMGT-spec AP calipers which I think are anodized.

My next issue is trying to decide whether I want (read: need) to take the dust seals out. In a perfect world I would without question, but AP doesn't have any agent for seal rebuild kits in South Africa. The real worry would be damage caused by powdercoat curing, which happens at 250-280 deg C (at least that seems to correspond with your guys, Tony). But the brakes are designed to operate around those temps and higher. Is anyone vehemently against this? Would it be safer to take them out with the hand of a surgeon, and re-fit the existing seals?

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

[Catalina Park]

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?

[Jezztor]

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?

Thanks, that much I know. Firstly, the car is 95% of the time a daily driven at sensible speeds, so nothing like competition conditions experienced. Secondly, these are high tolerance performance calipers, not stock, mass-produced generics. I expect the seals to have a much longer lifecycle as such, especially if they aren't taken anywhere near aforementioned design operating conditions. Again, I do not have easy access to new seals, living in (aside from other things) a motorsport-challenged country.

I replace my oil filter when it is necessary to do so, exercising as much preventative judgement as possible without it becoming a logistical or financial impracticality.

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

[Tony Matthews]

Glad that what I said made sense - I don't think the company will want to coat the calipers unless they are bare, so no seals, no bleed nipples etc. They use a high-temp. tape to cover areas to be left un-coated, and you, or someone, is going to have to blow all the brake fluid out! I say again, I haven't had auto parts coated yet, so I'm guessing...

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

[Jezztor]

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

This is South Africa, anything is available at the right price...

... except CP5100 seals.

[cheapracer]

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.

[Tony Matthews]

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? A lot of 'performance' road cars - Porsche, Ferrari etc, use powder-coated calipers, but no race cars to my knowledge, I thought Jezztor's vehicle was a road car...

What we need is some infra-red photography...

[McGuire]

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

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

[McGuire]

Would it make a significant difference?

Not really.

[Tony Matthews]

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

That looks like good stuff! I had forgotten about Eastwood, I used to get a catalogue regularly, but a change of address knocked that on the head. Ooh! Tools...

[cheapracer]

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.

[kikiturbo2]

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.

I have had some hi performance pads on my car that operated at such high temps that the bright red powdercoat on the calipers turned to dark red after two trackdays.... yet proper fluid kept the pedal nice and firm..


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..

[Jezztor]

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

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

Does look tasty - pity they don't seem to have local distributors.

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..

The caliper was designed as a hybrid for road/occasional track so I'm fairly sure it's got both the piston-mounted O-ring seal as well as a dust boot:
http://www.apracing....Discs_2758_2569

[Tony Matthews]

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!' Sniff...

I had a company BMW 1602 when I first worked for Motor Sport - after three consecutive traffic light drag-races (yes, I know) there would be no more braking effect than a stiff head-wind, and no powder coat to be seen...

[cheapracer]

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!!

[Tony Matthews]

No We wouldn't!!

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

[gordmac]

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?

[cheapracer]

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

I resemble that remark!

Pistols at Dawn scoundrel!

[Tony Matthews]

Pistols at Dawn scoundrel!

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

Got my powder coated chair parts back this arbo (that should make Cheapy feel nostalgic), they are smart!

[OfficeLinebacker]

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

LMAO

[Jezztor]

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?

I'm afraid the stupidity resides with me, as I imported them privately as a kit, not purchased locally. Local agents are doing the typical counter-intuitive thing with pricing during the economic crash, and so everything is 3-4 times more expensive than it sanely should be. I spent the best part of Thursday and Friday on the phone to AP and their various distributors in the UK (AP don't sell privately themselves). Only 1 distributor has stock (of 1 pack, which = 1 caliper) and so they've requested that AP manufacture some new ones. I'm not going to chance breaking the seals (non-restroom variation of the expression) during disassembly.

Prognosis: ball ache.

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

[Greg Locock]

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.

[Catalina Park]

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 agree with that. Just get some seals and fit them after you do what you have to do.
If you want to try and coat the calipers and re-use the seals you are an idiot.

[Canuck]

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). Using good-old fashioned patience, care and caution the calipers were completely stripped of all seals and then I taped them off. They came back from the powdercoaters in wrinkle black and a quick trip through the manual mill restored the machined Brembo logos. Calipers were re-assembled with the original seals (I suppose it makes a difference that the calipers were un-used).

To date they've functioned flawlessly, however they are on a v-twin motorcycle on the street - not exactly a taxing place to live.

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

[Tony Matthews]

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

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?

[McGuire]

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.

Yep.

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.

[McGuire]

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).

I absolutely DESPISE that style of product support. Drives me crazy. It's like they don't know they are cutting their own throats. This should not be, but many times you can find better product support outside a manufacturer's regular supply chain.

[Fat Boy]

Caliper seals are a consumable item.....

Do you re-use your condoms?

fixed.

[cheapracer]

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.

Ahhh 70's Triumph story. T140's were dry sumped and carried the engine oil in the main backbone of the frame.


Customer - restoring my Trumpy T140 can you rebuild the engine for me?

Sure thing but a bit of advice for you Mate, don't get the frame sandblasted.

A month or so later customer returns with ****ed engine.

You Guys are idiots, you couldn't rebuild a Victa lawnmower.

One look at the pistons in the box - err, Mate you had your frame sandblasted didn't you?

Yep, how did you know.......

[Catalina Park]

fixed.

Thanks.

[Jezztor]

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.

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.

You make it sound like I'm trying to invent a new spectral colour Just kidding. I'll be honest, splashing header paint onto the calipers sounds a bit hack. While I subscribe fairly religiously to the "go before show" ethos, I spent a good $1,600 on this kit, so would prefer them to at least look decent; OZ Racing uses my car to display at local auto shows; and analogous to welding, I like to believe that a proper functional job should also look smart. That said, I would definitely consider the ceramic-based poly paint you linked up above depending on surface finish, but I have enquired and it is not imported locally. If this was a track car, different story.

Appreciate everyone's opinions. Even if conveyed with an impressive lack in people skills, Catalina Park

[Canuck]

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?

There are two things I've found that work remarkably well to maintian that just-coated look. Wurth's Silicone Spray - spray the rag, wipe the caliper, so simple even I can do it. Alternatively, use WD-40 in the same fashion. Also works well to restore the look of faded wrinkle paint for a few days at least. Silicone spray doesn't seem to hold nearly as much dust as the WD-40, which is more like glue.

Of course being the kind of owner that cleans his bike with a toothbrush doesn't hurt either. This guy is unlikely to ever get dust settled on his $60k custom.

[Tony Matthews]

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.

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.

[Tony Matthews]

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

I'm unlikely to wrinkle-finish any calipers, but I hoard tips like yours about cleaning the stuff like a squirrel in Autumn, just in case, so thanks.

Paasche make a neat little detail blast-cleaner - I have one - which should be great for your teeth, possibly with pumice powder. That way you don't have to share your toothbrush with your bike.

[gruntguru]

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.

Granulated walnut hulls.

[cheapracer]

Paasche make a neat little detail blast-cleaner -

Thony, I thidn't know you fave a lisp

[Tony Matthews]

Thony, I thidn't know you fave a lisp

Thhh! Don't thell everone, Theapy, i'th a thecret!

[Tony Matthews]

Granulated walnut hulls.

I didn't mention a specific medium 'cos I don't know what will be required, but yes, if it will do the job. It'll shift cellulose and other paint from panels, but I can't remember if the calipers in question are 'natural' or not. I know, I should go back and read the post, but I'm a recidivist.

[McGuire]

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.

[Tony Matthews]

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

There, I've been all the way back to the first post - also, the calipers were, apparently, coated from new. I hear what you say, Mr McGuire, but as so many 'fast' road cars have powder-coated calipers... Or would you say don't, under any circumstances?

I would absolutely agree about the seals.

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

[Jezztor]

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..?

Again, we need no longer fret over the seals, as mentioned a number of posts back, an AP Racing distributor in the UK is having them re-manufactured - and until I have them in my hands, no re-building/-painting/-coating.

[McGuire]

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.

[Jezztor]

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.

[McGuire]

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.

Well, you sorta answered your own question there. Look at it this way: If the calipers are not blasted, then there is no way any abrasive blasting media can get into them. Problem solved, on to the next problem. Race preparation is based on the principle of making everything as close to optimal as we possibly can, with as little as possible left to chance or unknown variables. What we might reasonably get away with on a good day with a little luck on our side is an opposite sort of approach, which is not professional race preparation. There are many who hold that no type of abrasive media cleaning/blasting has any place on any component of any serious race car. For the most part I happen to be one of these people. With a very few exceptions that is my rule with collector cars as well.

[desmo]

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?

[gruntguru]

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?

Yes, plus corrosion resistance, wear resistance (hard anodising)