Kalogerus

iTrader: (3)

I received a used caliper replacement that was pretty rusty, not good. Solution? Bust the rust with some chemistry.

After some discussions and research with my brother, who is a better chemist than I am, we agreed that the process of oxidization of steel AKA rust can be reversed using some water, sodium bicarbonate and electricity. A process named electrolysis. Cost me $15-$20 bucks and a borrowed battery charger from a friend.

Before we start, please read these warnings carefully.

• Make sure this process is taking place in an open and well ventilated space. The resulting gasses include high amounts of hydrogen and oxygen, in concentrated amounts these can be quite dangerous.
• Do not use galvanized steel, zinc, nickle or any non-ferrous metals. These will cause plating of the caliper/parts.
• Do not use stainless steel, the resulting compound in the water is toxic and illegal to dump anywhere, although results are a bit better than regular steel.
• Make sure the polarity is correct, otherwise you'd be ADDING rust onto the caliper. The opposite of what we want.
  

Materials needed:

1. A plastic bucket, this must be made out of non conducting material.
2. A sacrificial piece(s) of steel, these will be our anode or positive electrode. Steel rubar pins from lowes are pretty good.
3. Rusty parts, these will be the cathode.
4. Steel wire hangers, these will make our connections.
5. DC power generator (e.g. Car battery charger). The higher the amperage the faster the process is. Also dont get one of those "smart" ones, those cut off power if they feel the "battery" is dead, this is disasterous as the only thing keeping the caliper from rusting even more is the fact that it is a cathode.
6. Spring clamps
7. Sodium bicarbonate (e.g. Baking soda), water and time

Steps:

• Fill your bucket with enough water to cover the part(s) you're trying to deoxidize, then add baking soda. I believe it was 1- 2 table spoons per gallon.
• Prepare your connections. I used 2 steel pins for the anode side and connected them together with 2 wire hangers. A third pin where the caliper is hung with another steel wire hanger (I didnt feel like submerging my charger clamp into the water). Make sure the anode and cathode dont touch under or above water.
• This is the most critical part, make connections and make em correctly. The ANODE (AKA the sacrificial pins) will take the positive lead from the battery charger, while the CATHODE (AKA the rusty caliper) will take the negative lead. DO NOT SCREW THIS UP.
  
  
  
  
  
  
  
• Now turn the battery charger on. You'll notice the rusty parts as well as the anode rods are starting to bubble, this means you're on the right track.
  
  This is about an hour into the process
  
  
  
  
  
  and this is about 5 hours into it
  
  
  

It's been 8 hours give or take, I am aiming for 12-15 hours to insure complete rust removal. I'll then update on how the anode rods and the rust on the cathode will look like. I touched it earlier and rust was already chipping off.

PS: This will NOT recover the rusted material in anyway, the rusted metal is gone, we're just transferring that rust from the cathodes onto the anodes. This will make cleaning it with a wire brush much easier.

Source of information: http://myweb.tiscali.co.uk/andyspatch/rust.htm

***********************************************************************************************

Notes:

• Results are here
• After scrubbing with a flat head and a steel brush, some rust dust was still in some corners and kept staining the other surfaces, after a thorough scub I suggest using a rust removing solution and wipe down every trace of rust. You can also use a thin wire brush like
  this one
  this one
  or http://www.lowes.com/pd_324828-995-3410481_0__?productId=3166529&Ntt=wire+brush&pl=1&currentURL=%3FNtt%3Dwire%2Bbrush&facetInfo=.

SC300NW

iTrader: (1)

Whoa! This is sweet and scary at the same time. It looks like an old college science project.

If anyone is planning to do this and has any doubts, DON'T DO IT.

Thanks for the project idea and pics!

Kalogerus

iTrader: (3)

Necessity has it. I cannot afford a brand new caliper and bracket and cannot afford going to somebody to blast it for me. This is where I roll up my sleeves and fix it. Worst case scenario is I'm out 15 bucks and a rusty caliper.

lilSCsteve

iTrader: (71)

Now that's some "home made" ingenuity right there! lol...

steve

sr71b

i'd end up in someone's hospital, but props for ingenuity!

rcchris7

iTrader: (1)

Where's the results! I love this bill nye sorta *****

Kalogerus

iTrader: (3)

I let it work over night, a bit over the edge but cant hurt. This is what I got this morning. Pretty nasty stuff.



This is the cathode after cooking...



...and this is one of the anode rods.



I wish I had a before pic of the caliper when it was rusty. Anyway, the outcome is disastrous... for the rust that is . Scrub it with a steel brush and whatdayaknow, see for yourself.





I'll finish cleaning it up after I come back from my appointments, but I am pretty content with the results. It was a fun little project, kinda amazing to see chemistry in a practical use like this, I hope my chemistry teacher doesnt see this thread so she doesnt say "I told you so".

sc400ka

hot damn! nice idea!

SC400slide

iTrader: (11)

Nice idea! Thank goodness in NM, rust is a rarity to be seen.

Photon440

iTrader: (3)

Great results. You see people doing this a lot in the hot rod/muscle car world where old parts are the norm, and as shown here the rust just goes away!

For those who are not ready to deal with electricity, similar results can be had by dumping your parts into diluted molasses. The chelation will remove all rust, giving you a new, 'just made' appearance. The down side is that it takes longer, more like a week.

daily400

man thats awesome. great results man.. can i throw a idea out there.. the company that makes wd-40 has a great rust remover personally used it and now always will. its called WD 40 300042 Gal Rust Remover Soak.. im posting this for the people that dont wanna take the risk of what you have done.

Kalogerus

iTrader: (3)

Thanks all. The speculation about electricity here is worse than it actually is. As long as you take the necessary precautions things will be fine. Also at 6 amp, you arent drawing enough current to electrocute yourself, not to mention that the charger I am using has a cool feature that it doesnt start charging until both terminals are connected to something that is drawing electricity.

At higher amperage I'd take more precautions like wearing gloves and avoid being around the solution without a mask or something as gasses will come out more rapidly and there is more to it than just oxygen and hydrogen, and those alone can cause harm in high amounts. All in all, it has been a fun experiment and the results makes it worth the time it took.

Kalogerus

iTrader: (3)

You will still have to scrub the rust out of it, bad rust cases can get very very hard to deal with especially in tight areas like the inside of the caliper. I used a bit of PB blaster but it was looking like a 10 hour of hard scrubbing/sanding job. Chances are you'd also sand away some of the untouched metal and not just the rust which was the deciding factor in going this route. This is used to restore rusty historical stuff, like 400 year old horse shoes where every detail need to be preserved.

lilSCsteve

iTrader: (71)

In for the final results...quick question are you going to paint/powdercoat when it's all said and done?

steve

xxtoobsxx

iTrader: (4)

good ol electrolysis and using a sacrificial anode. I have done this before, usually on nickle plated fishing equipment or aluminum. Works faster if you have a direct 12volt power source or an AC current. But looks good...see nerding and cars do mix!!