DIY: Clean rust parts (in this case, brake calipers)

[nmp411]

Please read the warning at the end before attempting this

The problem:
I needed to strip my REALLY rusty brake calipers in order to get them powder coated.




The solution:
I tried using my sandblaster (siphon tube from craftsman that is a great tool!) but the rust was so thick it took 1/2 hour just to get this far.




So, research time. I really didn't want to spend money to get them blasted since I have my own. I ended up stumbling across a web page discussing electrolysis. Being an engineer, I had heard of it, but never tried it. So I thought, "It's worth a shot!"

Onto the directions....

What you'll need:

Dirty parts (Will only work with iron and other metals. However DO NOT use stainless steel, the chemicals it releases during the reaction are toxic and illegal to dump. Also, it will not work with copper)
Borax (sodium bicarbonate laundry booster)
Water
Rebar- for electrodes (or similar metal rods)
Steel wire or banding - for connecting parts/electrodes (I used metal coat hangers)
12 volt battery charger
Non-conductive tub/bucket (cannot be electrically conductive)
Clamps


Procedure:

1)
Since the parts will be submerged in the water, I needed to make sure the brake rotors were sealed up so no solution could enter the piston area. I did this by leaving the piston and rubber boots on the calipers, as well as cutting the brake lines off of my parts car, screwing them into the connection, and then taping them off.



2)
Prepare the tub:
I used a 10 gallon rubbermaid tote for this. I used four pieces of steel rod as the electrodes. They were a little rusty, so I used the grinder on them before starting.





3)
I then clamped the rods to the side of the tub as shown. The more rods the better. It allows more debris to be picked up, and allows the part to be surrounded by electrodes.



4)
Next I used the metal coat hangers to hang the calipers and brackets over a metal plate going down the center of the tub. It is important to make sure the coat hangers are in contact with clean, non-rusty surfaces on both the metal plate and suspended parts. It is equally important that the parts or hangers are not in contact with any of the electrodes.




5)
Use more coat hangers to connect all of the electrodes together. Be sure that they are not in contact with the parts, hangers for parts, or metal plate. These two systems need to be electrically isolated.

(No picture here, sorry!)

6)
Create the water bath. Use approximately 1/2 cup borax (I eyeballed it) to every 5 gallons of water. Mix together thoroughly and pour in the tub ensuring the parts are completely submerged.





7)
MAKE SURE THIS STEP IS DONE CORRECTLY, IF NOT RUST FROM THE ELECTRODES WILL BE PLACED ON YOUR PART (the opposite of what you want )
With the battery charger UNPLUGGED, connect the negative lead to you plate connected to the parts you wish to clean, then connect the positive lead to the electrodes. (Using more than one charger is a good idea for large batches, I used two)



8)
Now, make sure everything is done correctly, then plug in the charger(s)
Within a few seconds, you should be able to see evidence of the reaction. Bubbles will start to form on the part and float to the surface. (READ THE WARNING ABOUT THESE BUBBLES)
(In my picture below, you can see the really hazy water just above the yellow clamp, this is the result you are looking for)



After a while, your water will start to turn very dirty, and you will notice the rods starting to accumulate a lot of particulate.




I let mine sit overnight so they would have plenty of time to work. It was probably a bit of over kill, but it worked!

This is what the rods look like after the reaction



9)
When you feel like the parts are done, unplug the charger(s) and remove the parts. The water is safe to dump in your lawn, in fact it is good for it since it is iron-rich.
Most likely, the parts will still have a lot of rust on them, however it just flakes away very easily! I used a screwdriver and a wire brush.





Now, the parts will have a black coating due to the reaction. I decided I would hit them with my sand blaster now since it would be a lot easier. You could scrub them with a cleaner of some sort to remove the layer though.

Sand goes everywhere when you are using one of the blasters though. Make sure to wear eye/breathing/ear protection




And, the finished product! I am more than pleased with the results! It was a fun project that was well worth it!






WARNING: The gases produced during this reaction are hydrogen and oxygen. Be sure to do this in a well ventilated area (not indoors). Hydrogen and oxygen are very dangerous in high concentration and are likely to cause an explosion when mixed with sparks or an open flame. I am not liable for any injuries you may incur while doing this procedure. Just be safe!

[kipwinger]

Very interesting. Going to have to try this on my spare brakes.

Thanks for the write up.

[Supra330Xi]

thats seriously some cool nerdy sh*t!!!

Thanks for taking the time for the write-up!

[snake109]

best post ever

[Hova]

[nmp411]

Thanks for the praise guys! I had fun doing it, and it is soooooo much easier than trying to blast it all off or any other method. And the final blasting went really easily. <10 minutes per piece.

[clevertd]

Great thread

[Husky]

Nick, awesome idea!!! Beats 5 hours in the blasting cabinet any day!

[BavariaE34]

you mean like zis? lol
[ame]http://www.youtube.com/watch?v=E3jifRRdcbQ[/ame]

[ArnZ]

I love the look of clean braking parts. Recently i just used some black brake caliper paint and sprayed my caliper and rotor. Looks 1000x better then rust look.

Plz post some pics after you get them powder coated.

[WolfStrong]

WARNING! DO NOT USE Baking Soda!!!!!

The gases that come out from those bubbles will NOT be just Hydrogen and Oxygen, rather a mix of Hydrogen, CO2, and CO in enough quantities to be lethal as well as some other unpleasant gases! As far as stainless steel, there are no negative side effects to using that, and in fact it is the preferred metal to use. Use regular tap water (which is already 'dirty' enough to conduct electrolysis) or distilled water with . Also DO NOT use salt, Sulfuric Acid, Vinegar, or Sodium sulfate. The one ting Baking Soda won't do well is make a flammable gas.

Now you can use Lye (NaOH, Sodium Hydroxide, used to open drains!) which will be MUCH safer, however will still produce flammable gas. Fortunately as long as it is done with even half decent ventilation, you won't run into any problems with explosive gases. Hydrogen is a VERY light gas, and as soon as it hits the air, is usually dissipated/moved away so fast that the area isn't even flammable anymore. The key is that the area be ventilated so that it does have a place to go. You can even take a lighter, and place it right on top of the water, and the worst that will happen is that the smaller bubbles will crackle, and the larger ones will make some big pops. Actually kind of fun!

Oh, and yes I have played with electrolysis a lot, and it can actually be a lot of fun, but like everything, don't be foolish with it.

[MaxSteel]

OP, I think by brake rotor you mean caliper.

Nice write up BTW. How much is one of those battery chargers?

[skylinergtr]

nice and interested write up, but wouldn't white vinnegar give the same results? still an interesting experiment indeed.

[T444E]

So this doesn't effect any of the rubber seals around the pistons and such?

[misswin]

this is super freakin' cool.... and makes me sad that i didn't pay better attention in chemistry while i was in HS.

[sweet e36 pimp]

very cool post. thank you for sharing!

[swill424242]

This is Awesome nice wright up

this shold be but in DIY

Section

[cis8vgti]

With some members having meth lab experience, this should be a cake walk.

[E34N]

Excellent write-up. It's cool seeing people's DIY's and sharing their experiences, especially if it's something new.

This is similar to removing chrome. I almost did this with some old rims, but decided not to since the volume would be x10 and of the fact that I didn't have any experience with it.

[sweet e36 pimp]

With some members having meth lab experience, this should be a cake walk.

LOL

[nmp411]

Plz post some pics after you get them powder coated.

Will do!

WARNING! DO NOT USE Baking Soda!!!!!

Thanks for the additional info!!!

OP, I think by brake rotor you mean caliper.

Nice write up BTW. How much is one of those battery chargers?

Yes I did mean caliper, thanks!
I don't know how much the battery charger is, they are both my dad's. I would think you can get one for $40 or so.

nice and interested write up, but wouldn't white vinnegar give the same results? still an interesting experiment indeed.

I think vinegar would work too.

So this doesn't effect any of the rubber seals around the pistons and such?

As far as I could tell, no. But since I am getting them powder coated I will be removing them and replacing the seals with new ones. But a day after removing them from the solution, the rubbers are still in good condition.

this is super freakin' cool.... and makes me sad that i didn't pay better attention in chemistry while i was in HS.

Thanks!
I forgot a lot of chemistry as well!

very cool post. thank you for sharing!

Thank you!

With some members having meth lab experience, this should be a cake walk.

Haha!

Nick, awesome idea!!! Beats 5 hours in the blasting cabinet any day!

Sure does!

Great thread

Thanks!

[nmp411]

.......And.....


Done!

[moroza]

OOOH and AAAH and well done! There's putting that high school diploma (and probably more?) to good use.

Regarding some of the chemicals: CO2 is not toxic. CO is not toxic if you ventilate it away. H2 is not toxic but it is flammable in regular air (which contains O2); extra O2 may increase the likelihood or rate of reaction with H2 but since it's already 20% of atmospheric air, it's not a major difference.

What I would be worried about is using borax, baking soda, or some other chemical that has things other than the main ingredient, and the additives giving off vapors that are worse than CO or H2. I read a while back about someone who welded a part that had trace amounts of brake cleaner on it, and that releasing essentially nerve gas, getting the person hospitalized with emphysema. I've been nervous about chemicals+fire (or electricity) ever since.

[nmp411]

OOOH and AAAH and well done! There's putting that high school diploma (and probably more?) to good use.

Regarding some of the chemicals: CO2 is not toxic. CO is not toxic if you ventilate it away. H2 is not toxic but it is flammable in regular air (which contains O2); extra O2 may increase the likelihood or rate of reaction with H2 but since it's already 20% of atmospheric air, it's not a major difference.

What I would be worried about is using borax, baking soda, or some other chemical that has things other than the main ingredient, and the additives giving off vapors that are worse than CO or H2. I read a while back about someone who welded a part that had trace amounts of brake cleaner on it, and that releasing essentially nerve gas, getting the person hospitalized with emphysema. I've been nervous about chemicals+fire (or electricity) ever since.

Thanks! (And I am in school for Mechanical engineering )

I remember reading about that guy as well (It was in a motorcycle magazine, correct?). It is a scary deal, with anything that you could potentially breathe in, you really have to know what you are working with.

[4Hummer]

Just a word of advise, as I have been using this method for many years on my 4x4 Rock Crawler

You can't use a "SMART CHARGER" it has to be an old school style (Non digital) The Smart Chargers will detect that the voltage is not increasing on the "battery" and shut off with a "Bad Battery" warning.

You can bypass this on some smart Charger by connecting the Charger to a spare good battery, and that battery to the contacts for the electrolysis tank,

However even this way the charger will turn off once it thinks the battery is fully charged. (which requires you checking the charger every couple hours and turning it back on)

You can also use (My method) an AC to DC adapter 12V DC output 2amp minimum I've found the higher the amperage the faster this process works (currently using a 20amp adapter)

Like this. Just cut and splice the wires with alligator clips (ensuring you have positive and negative correct) and connect the alligator clips to the probes. Check the label on the adapter it will tell you the Input Output


check your old electronics you might have one kicking around