Removing chrome from a brake disc

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I turned the chrome off both disc on my MKIII with a automotive brake lathe. They do both sides at once. The chrome came off in one pass.

I sand blasted and painted the discs, new EBC pads, that was 20 years ago. The brakes work much better, pads last about 25,000 miles.
 
Removing chrome from a brake disc


Removing chrome from a brake disc


Removing chrome from a brake disc
 
OK, sorry in advance and i dont know SFA about M/Bikes, so tear me to bits if you want............ But, I cant believe what i read here sometimes, but caustic to remove chrome :roll: :roll: :roll: :roll: .. And to try to DIY chrome removal in this sceranio with a lathe...... Please.. I ask the question why the hell did they chrome them in the first place :shock: but thats another story. Solution is simply .. take the disc/s to a reputable engine reconditioner who has a "GRINDER" with magnetic bench (faces heads etc) .. step 1, first surface grind opposite disk face to hub connection flange............. So that face is parralel to hub.............. 2nd Step, then chuck over to other side onto the "magnetic" bench and then the 2 disc face can be ground Parallel to each other and aligned with hub... It cost me AU$51.00 for the two discs. Each disc lost a total of .0015thou =SFA, the best value for money deal ive had doin my mk3.
 
So olChris, let me make sure I understand correctly. You don't approve of using the lathe and grinder? Why not?

Russ
 
Russ!! That is awesome! Plenty of lathes have grinder attachments which are expensive. Your idea is great.
Dan.
 
Getting it set up so that it grinds across the full face of the disc takes a little messing around. I used some quick dry spray paint and ocasionally splattered some across the disc so that I could be sure the grinder was still positioned correctly. I went really slow at his so as not to create heat. The bungee chord you can see in one of the photos helped keep the feed from backing off from the vibration. It ended up working like an auto-feed. I used a Ridgid AWD40 double row diamond cup wheel for most of the work. I found on on Ebay for 27 bucks with free shipping.

To make sure the disc ran true in the lathe I fabricated a shaft with a flange out of aluminum and trued the face of the flange with the lathe. DBR at 139 bucks is still a good deal. But this project kept bugging me so I finally just did it. The surface scratches are actually very light. I am convinced it is a truer surface now that it was previously. So often when you see a disc with the chrome worn off the pattern is not uniform. Its because these discs where a little less than perfect when they where new. I have .233 thickness remaining after this project and probably took off a little more than needed.

Russ
 
Unless the disk is ground or turned on both sides at the same time it is very hard to keep them exactly the same thickness all the way around. Just a tiny bit of deviance will cause brake pulsing after using them for a short time. Even using a magnetic chuck on a surface grinder often ends up with a pulsing brake.

An automotive disk lathe with two opposing carbides on a cast rotor or a special grinder to grind both sides of a stainless disk at the same time is the correct procedure. Heating and disk deflection usually causes other processes to pulse after a few hundred miles. Jim
 
comnoz said:
Unless the disk is ground or turned on both sides at the same time it is very hard to keep them exactly the same thickness all the way around. Just a tiny bit of deviance will cause brake pulsing after using them for a short time. Even using a magnetic chuck on a surface grinder often ends up with a pulsing brake.

An automotive disk lathe with two opposing carbides on a cast rotor or a special grinder to grind both sides of a stainless disk at the same time is the correct procedure. Heating and disk deflection usually causes other processes to pulse after a few hundred miles. Jim

I guess I will find out. I'm too stubborn to turn back now! Or I a better find someone with a automotive lathe that can turn this disc a couple more thousandths for me. Using a dial gauge I can't find any deviation in the surfaces. I know that sound remarkable but its true. Of course once I got this set up I let it spin for nearly 8 hours to achieve the surfaces, so the amounts coming off in a single pass was essentially nil.
 
We've already discussed the issues with an automotive lathe finish.

But good on you for the attempt. If you were careful enough it could work. Out school, like people who scrape bearings. :mrgreen:
 
swooshdave said:
We've already discussed the issues with an automotive lathe finish.

But good on you for the attempt. If you were careful enough it could work. Out school, like people who scrape bearings. :mrgreen:

Have you had any issues with your DBR surfaced rotor? I assume it is one one on the proddy racer? Now it is off to the shed. I have some shoe polish to rub into my tires!
 
swooshdave said:
We've already discussed the issues with an automotive lathe finish.

But good on you for the attempt. If you were careful enough it could work. Out school, like people who scrape bearings. :mrgreen:

The problems with using an automotive lathe are caused by the operator -not the lathe. If the correct radius on the carbide and the correct feed are used with a disk lathe then there will be no spiral grooving to wear-in.

This was demonstrated to me at a GM brake clinic and proven to work by cutting many hundreds of rotors in the past 40 years. Jim
 
comnoz said:
swooshdave said:
We've already discussed the issues with an automotive lathe finish.

But good on you for the attempt. If you were careful enough it could work. Out school, like people who scrape bearings. :mrgreen:

The problems with using an automotive lathe are caused by the operator -not the lathe. If the correct radius on the carbide and the correct feed are used with a disk lathe then there will be no spiral grooving to wear-in.

This was demonstrated to me at a GM brake clinic and proven to work by cutting many hundreds of rotors in the past 40 years. Jim

Yeah, but you have to find the operator who knows how to do it.
 
stockie2 said:
I have the original chrome on, I up rated my master cylinder to 1/2" and the brakes are great.

Cheers Richard

P.S. brakes squeal though!

I put AP Racing pads from Commando Specialties on and they bite so well into the chrome that I can leave it alone.
 
][/quote]

Very true. It is no longer equitable to turn rotors anymore with $100.00 per hour labor and $35.00 Chinese rotors. Jim[/quote]



AS i stated before i got my 2 rotors ground for $52.Au ...... ( 3 surfaces gauranteed to be PARALELL).. Im really happy with that

If i could have found discs at $35ea i would have gone there, but all i fould was $130ish each +post= $100+... So can you please show me where these are available for that price of $35 each.

PS. labour here in OZ at a reputable machine shop/over the counter like i did is $140p/hr...
 
The 35 dollar discs are for Subarus, not Commandos. Just be glad you live somewhere that still has reputable machine shops!
 
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