problems w/electrolytic rust removal
Close
Login to Your Account
Likes Likes:  0
Results 1 to 13 of 13
  1. #1
    Join Date
    Oct 2005
    Location
    New Jersey
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5

    Default problems w/electrolytic rust removal

    I haven't done much in the way of troubleshooting, but I figured I'd post this since I'm currently parked, and got the 'net in front of me...

    I have a 32 gallon plastic garbage pale, thought I'd try this thing out. I filled it w/soapy water from the shower LOL (might as well make good us of it). The soap (Irish Spring!) isn't my problem, is it? I put oh 3/4 of my Potter 32" lathe bed in it, standing on end. I took a galvanized (another potential problem?) piece of steel strap, the kind w/the holes drilled all along it's length) and hooked all that up to a battery charge. Meter never went past 3 amps, and generally hovered around 2. Oh I did mix up probably more then half a box of Laundry Soda and threw that in the pale. Most sites call for a tablespoon/gallon of water, so I at least met the requirement and probably surpassed it. Probably 20-25 gallons of water in the tub.

    I plan to make a stop at Home Depot and buy 1 or more pieces of rebar. I'll add that I didn't remove any rust on the bed (which has been sitting out in the rain for years possibly). I could try that, and the rebar, and possibly add more laundry soda. The charger is old, but hums nice, and I can't find my VOM to see if it's reading is accurate (something tells me it is). I haven't opened up the charger, so I don't know what's in it, or what it would take to ramp up it's duty, assuming that that's even the problem. A beefy transformer and a handful of other components to turn the oscillating AC into DC, as is the case w/nearly every other power supply on the planet I suppose.

    Your comments are more then welcome.

  2. #2
    Join Date
    Oct 2005
    Location
    New Jersey
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5

    Default

    I forgot to mention that I had it in there for an hour or so. Didn't do much more then make a faint rust colored ring around the bed. So I can assume at least I didn't apply the wrong polarity like a yutz.

  3. #3
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    24,058
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4169

    Default

    Missed the part where you tell us what polarity you
    *did* have it hooked up for.

    Jim

  4. #4
    Join Date
    Dec 2007
    Location
    Central Ohio USA
    Posts
    3,696
    Post Thanks / Like
    Likes (Given)
    63
    Likes (Received)
    1659

    Default

    I have read that the process is essentially "line of sight" between the rust and your electrode. Are multiple electrodes in order?

    Chip

  5. #5
    Join Date
    Oct 2005
    Location
    New Jersey
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5

    Default

    well that obviously has to be done correct. I could have been thinking the opposite of "conventional" notation when it comes to polarity (the electrons are really moving from the negative lead to the positive, meaning they're flowing from black to red), but that's just goofiness on my part, if that was the case. I'm back at it again in a few hours so I'll have to report back maybe tomorrow. Hopefully I'll be able to find my VOM so I can verify if the charger's meter is accurate. One way or the other I guess I'll be able to figure out if the charger can even deliver the needed 10 amps or close (it's an old Schumaker by the way). I'm also utilizing a 50' extension cord, but I doubt that's hold up progress.
    What would happen if instead of 12 volts, 110 was used LOL? I have an old variac that could be made to deliver DC w/o too much effort. Does it have to be smooth DC, or would just using a half or full wave rectifier w/o any capacitors and whatnot be sufficient? I can't see why not, it essentially would just be DC w/something less then 100% duty.

  6. #6
    Join Date
    Feb 2004
    Location
    Bham, AL
    Posts
    762
    Post Thanks / Like
    Likes (Given)
    3
    Likes (Received)
    48

    Default

    Current is the significant parameter. Certainly more volts might help but 110V at 10amps is
    going to be boiling your bath. Surface area is the 2d major parameter: more surface
    area, the higher the current required, unless you expand the third factor which is time.
    For a large piece as described, 3amps will require a day or so in the bath, maybe 3-4 days.
    If you can bump it to 8-12 amps it will go a lot faster. No filter needed on the DC,
    doubt your battery charger has one anyway. Be careful with that variac, unless you have
    one rated a 1-2 kw, you would need to closely monitor the current draw so as not to exceed the ratings. The wiring can only stand the rated max amps eg a kilowatt variac can deliver 8-9 amps regardless of voltage so if set to 12 volts it is only good for 100-120 watts.

  7. #7
    Join Date
    Jan 2005
    Location
    Southcentral, AK
    Posts
    2,574
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1632

    Default

    Okay, several things:

    First, there shouldn't be a problem with the soap, but it's kind of unnecessary.

    Second, check the label of the "Laundry Soda" and make sure it's actually (mostly) sodium carbonate. If it's not the first material listed, I'd say try again.

    Third, don't use galvanized materials. The process should still work- I'm not sure- but the zinc leaches out into the water. No reason to contaminate it, especially if you're going to be disposing of it by dumping it on the lawn, in a storm sewer or down the drain.

    Fourth, add more sacrificial plate. The positive or waste plate should be roughly the same surface area as you're trying to strip. A small sheet of 22 or 24 ga sheetmetal is cheap, and easy to cut into sections with some snips. Or be creative- I used a bunch of pieces left over from dismantling a large copier, and you might find somebody throwing away an old microwave or something, that you can cut some panels off of. Any clean steel will do, and it gets nasty-rusty, so make it cheap as possible and stuff you won't mind throwing away.

    Fifth, it's a slow process, and slower still if you have a very small positive plate. Expect the process to take at least all day, overnight. Large pieces with heavy rust could take several days. It won't hurt a thing to leave it in even longer. Some people have said that a low amperage and longer time does a more thorough cleaning.

    And sixth, the data: Red/positive to the waste plate(s), black/negative to the piece to be stripped. About 1/3rd to 1/2 cup of washing soda or baking soda per five gallons of water. Don't use galvanized, don't use stainless steel. Have a hose and several stiff brushes to give it a good scrubbing when you're done. I use a small wire toothbrush on some stubborn spots. Have a good protectant on hand, as it'll instantly get surface rust as soon as it dries.

    Doc.

  8. #8
    Join Date
    Jan 2008
    Location
    Andalusia, Alabama
    Posts
    797
    Post Thanks / Like
    Likes (Given)
    43
    Likes (Received)
    9

    Default

    I have 5 PCs. of 1/4 x 3/4 flat bar set at even spaces around a 7 gallon bucket. Hooked togather with 12 ga wire it works very good.

    I also use a old computer power supply instead of a battery charger, It also works good...

    Paul

  9. #9
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    24,058
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    4169

    Default

    Remember the name of the guy who invented this de-rusting
    process:

    Leo Ger.

    Loss of Electrons is Oxidation.

    Gain of Electrons is Reduction.

    You want to add electrons to the workpiece, which
    means the (-) wire goes to it.

    Also the NaCO3 goes into solution faster if the water
    is hot to start with. It'll warm up when the current
    starts to flow, but hot will get it going in a hurry.

    Jim

  10. #10
    Join Date
    Oct 2008
    Location
    west jordan, utah usa
    Posts
    68
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    I began using electrolysis last year and now use it a lot on old tools. When I first started I had a similar problem where I would begin the process and it would start at 2 - 4 amps then drop to 1 - 0 amps in a short time. I am using a newer auto battery charger for a power source and I learned that many newer chargers have a sensor of some sort in their circuit that acts like an auto shutoff or current reducer which is supposed to keep a battery from overcharging. This can reduce or stop the current flowing from the charger if its wired directly.

    To overcome this problem a battery is wired between the anode and the charger which results in the charger remaining in a continuous charging state. When I wired the battery into my system it immediately jumped to 10 amps and stays close to that through the process if I keep the anodes clean. Here's a link to the info I used to solve this problem: http://wiki.owwm.com/RustRemovalByElectrolysis.ashx

    This is what the water looks like in my tank after about 30 minutes of current.



    I think the electrolyte is a significant factor in the process because it directly affects effective transmission of current through the water. Sodium carbonate (soda ash) is recommended because its easy to get and will give the best results without the hazards of other chemicals. Arm and Hammer Washing Soda is what I use because I can get it at the local grocery store but my brother in Texas uses soda ash from a pool supply store.

    Good Luck

    Rog

  11. #11
    Join Date
    Oct 2005
    Location
    New Jersey
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5

    Default

    Day 2's progress: the whole box of soda is in duh soup. Arm and Hammer, 3lbs. 7oz. IIRC. This DID make a difference. The width of the bed is about 3", and I substituted 24" rebar for the other thingee. I at one point had it a hair over 7amps. Fiddled w/it, it dropped down to 5 and dipped lower as time went on. Ended up at around 3amps when I quite (not at this time going to leave it plugged in overnight, doing this indoors - sort of).
    I inverted the bed after the first day, to see if the solution itself had any effect on the rust. I scrubbed the submerged not already partially electrolyzed part w/copper, and it didn't "smooth up" like the other part. After 2.5 hours of zapping, the rust came off more readily (I'm still a good ways away from clean iron though, and no pun intended).
    This is an informal test. I really want to have a better tank or whatever to submerge an entire piece and really crank up the juice. Yes a length of 3" or 4" CRS as the anode (do I got that right?) would be a better idea. Or angle iron even. After the current dipped down to 3 amps, I pulled the rebar out and gave it a very quick going over w/the copper scrunchy, and even that made a difference. And that's another reason to use something flat as the anode(?) because it can be cleaned up quicker. For better current flow.
    It softens paint too. This might actually alleviate the need to strip items (ammonia works so good). The silver spray paint (can't remember if it was Rustoleum or Walmart's brand) pretty much disappeared altogether. The blue and red Rustoleum (brushed on) was more resilient.
    After I get around to stripping and derusting these boys, I think I'm going to try my hand at plating them.
    This little Linux based netbook doesn't have the facilities in order for me to post pictures w/i the accepted limits, not easily anyway, so I won't be able to right now. I'm sure it would be good for a laugh - looks like a foamy bubble bath.

  12. #12
    Join Date
    Jul 2007
    Location
    Melbourne, Australia
    Posts
    109
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    0

    Default

    I've used Electrolysis for numerous projects and i've found that 24V at 10+amps to be more than sufficient in a 50L tank. using scrap metal from copiers and computers as the sacraficial anode.
    Although the system is wired in reverse during this video, [for cleaning the anodes], you get the idea! http://www.youtube.com/watch?v=vXFawrxMOnA

  13. #13
    Join Date
    Oct 2005
    Location
    New Jersey
    Posts
    340
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5

    Default

    putting a timken bearing headstock in such a solution is obviously a bad idea I guess.

    what about zinc based components (Atlas gears and such)? What effect does this process have on metals other then steel - brass, zinc, chrome plated parts? Is it useful for things other then derusting, general corrosion of all types? What about battery acid? What if you had a circuit board that was fouled from a battery leaking?


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
2