Restoration Tip: Electrolysis Derusting

[Ralph Volkert]

Ooops I forgot to mention...If degreasing or paint stripping is your goal then do that. But that strength of solution is really too strong for an electrolysis solution to restore and conserve an item. It will not not only conduct current it will REALLY conduct a LOT of dangerous current unneccessarily.

[Bob Moseley (RIP)]

Morning Ralph (here at least) - Andrew Westacott's article on his site on this subject has certainly demistifyed the whole procedure for me. In fact eminating from that I will be changing some of my procedures and building a more efficient and safer de-ruster.

And as a general comment, here with Ralph, we have an expert in another field, namely science, upon whom we can draw advice from. Move over Wikipedia.

Bob

[maple_leaf_eh]

Originally Posted by Ralph Volkert

...

Caution about using alloys and or stainless steel as sacrificial anode... The alloys such as chromium and other materials are released into the solution
These metals are extremely toxic and extreme care should be used when handling. ESPECIALLY if you are reusing the caustic solution. and allowing the waste metals to accumulate. Do not just throw this solution away in your yard or down the drain. Using just mild steel or an inert material will not create a toxic solution. It will remain just water with caustic pH.

I've read this thread end to end and find the chemistry of the simplest things fascinating. But, I read all these chemicals and acids and solutions mentioned without much discussion of disposal. Bob warned about splashing your clothes, hands and eyes. Another fellow damn near blew himself up with a hydrogen gas arc! So, what happens to the immersion bath after the part is clean? Do you guys pour it out on the ground, down a sewer or neutralize it with the opposing Ph agent? Inquiring minds want to know.

[Bob Carriere]

.....Yes Terry if splashed you wind up with very holy pants and shirt sleeves.

Solution is to splash clean water immediately thenit only bleaches the pants.

The caustic solution realy removes the grease on your hands..... along with disolving a layer of skin.

Parts, after derusting were pressure washed in the gravel driveway.... keeps the grass from invading the driveway.

45 gallon drum of caustic solution was dumped on the ground near the barn on a particular heavy rainny day....... no bald squirrels were observed in the following days...... some dandy lions took a nose dive.

We always did our work outside so hydrogen was never a problem.... the hydogen sulphide released by the Rotters was far more offensive.

We also sand blast old, I assume lead paint, CMP paint and the sand does collect extensively in front of the barn. In certain areas like Phil in NH, who is next to a water reservoir, his expended sand has to be contained as a toxic substance and disposed in a special site.

So far things have been very casual in Hammond.

The strange behaviour of the Rotters may be a symptoms of lead posioning...

BooBee

[huphuphup]

I tryed this in a 5 gallon pail with a 40 amp charger and it took about 72 hours to strip a badly rusted screw jack. I assumed that the washing soda (which I couldn't find) was the same as Arm & Hammer baking soda but now wonder if that might explain why it took so long. Anyone know if they're the same thing?

[Alex Blair (RIP)]

Originally posted by huphuphup
I tryed this in a 5 gallon pail with a 40 amp charger and it took about 72 hours to strip a badly rusted screw jack. I assumed that the washing soda (which I couldn't find) was the same as Arm & Hammer baking soda but now wonder if that might explain why it took so long. Anyone know if they're the same thing?

Same family but different...

Washing soda--sodium carbonate--is in the same family as baking soda. It has just been processed differently. It is much more caustic/alkaline, with a pH of 11, and while it doesn't give off harmful fumes, you do need to wear gloves. It is found in the laundry section of most supermarkets. Arm & Hammer is one brand; Shop and Save has a generic house brand.

Washing soda cuts grease, cleans petroleum oil, removes wax or lipstick, and neutralizes odors in the same way that baking soda does. Don’t use it on fiberglass, aluminum or waxed floors—unless you intend to remove the wax.

[Bob Moseley (RIP)]

Just to enhance Alex's answer;

Washing soda is sodium carbonate
Baking soda is sodium bicarbonate.

Washing soda is what grannie used to use in a copper before modern detergents came along.

Bob

[Dave Page]

Hi,
I tried this system last night and am very pleased with the results to the single bolt I cleaned but want to know:
1. are there any decontamination/neutralizing issues prior to priming or parkerizing and if so what is that step?
2. has anyone had success with processing batches (a handfull) of nuts and bolts held in a wire basket?
Cheers,
Dave

[Bob Moseley (RIP)]

Dave
Once I've derusted I wash the article in clean water, dry, then apply a metal conditioner. The one I use contains 24% phosphoric acid and I dilute this down to half strength. Just paint this on and let it dry for about 30 minutes. You will notice a white powdery coat has formed that you brush off. I then prime immediately with a good etch primer.
Bob

[Snowtractor]

...used to work at a rock and roll rotational plastics molding company. We made linear low density polyethylene containers in all sizes. The septic tank was rectangular 2 feet high by 6 wide by 14ft long. With the top cut off it would take a jeep frame no prob. Also the 1200 gallon ( as I recall ) was circular about 5 feet at the shoulder and 8 feet in diameter with a flat bottom. This would take a cab easy. They were about 1000 cdn. We did have the odd piece that didn't turn out or the wall thickness was too small that you could buy for peanuts.
Alternatively a wood crib of appropriate size with a vinyl liner should work. Find someone getting rid of one of those above ground pools and offer to dispose of it for them . Even new they are about 300 bucks for the the small version. Buy it and you have one large caustic tank...just keep the kids out of it.
Sean

[maple_leaf_eh]

You guys are a bad influence. I decided that chemicals and solvents were too much trouble to attack rusted parts, so I made a backyard electrolysis tank. The difficult step was finding washing soda in Canada. It seems to be an America only consumer product. Fortunately, one of the pages I read described how to convert baking powder into washing soda. Bake it at 300 deg F for an hour to drive out an unwanted molecule.

The set up is my 12v battery charger through a leftover 12v battery, jumper cables, some steel plates, a pair of vise grips, some chain and a piece of steel fencepost, rainwater and couple tablespoons of the powder. I used copper wire to hang the parts from the chain.

Yes, it fizzed and yes the surface coatings were softened or slid off. More time in the tank is required. Hours (like overnight) versus 1 or 2 in the evening. Mark II will be bigger and deeper with more steel plates. I will try to rig some permanent hooks on the crossbar. The big question now is how to get good electrical contact for small parts like screws.

[Bob Moseley (RIP)]

Hi Terry - I cannot believe you can't obtain washing soda in Canada. It is the stuff grandmas used before detergent and they used to boil their clothes in a copper. If you can obtain some scrap stainless steel, that is the best anode (+) and use stainless wire to hang everything. Stainless is the best conductor. I don't know how powerful converted baking soda is but with washing soda the ratio is one pound to a gallon.

Re. screws, I have not tried it myself, but maybe if you put them into a stainless sift and connect that to the diode, that may work. If you try that and it works, let us know please.

Bob

[Bob Carriere]

Hi Terry

Best bet is a recycled plastic 45 gal. drum.....cut off the top with a jig saw.... no it will not explode...... allows you to dip bigger peices.... even full axle housing if you do one end then the other....

You will need some cheap yellow nylon rope for hanging things.

Washing soda is readily available in rural Home hardware stores.

Remember the bigger the sacrificial plate is ....the faster it works and the more currant it takes. I used a strip of Stailess steel ( 40 x 18 in) from a recycled restaurant counter..... and curved it to fit inside the barrell..... all around the perimeter.....

Just hang the pieces from the centre.... direct line between SS and parts to be cleaned is best.

I used a mild lye solution.....also from Home hardware..... but it is caustic and the drum can only be dumped on a heavy rainy downpour.

I cheated and made my solution very strong..... it removed rust.... grease and even paint form cast surfaces.....also drained two large batteries in a few hours...... careful with just an average size battery charger.... you can easily over load them..... some will have a safety shut down//// cheaper ones will just fry themsleves.

Really workes wonders......

Small parts...... screws and bolts..... I usually replace them with new stock... but if I had to clean them I would be inclined to screw them in a thin sheet of SS and hang it in the barrell.

SS as a sacrificial plate will not alter color.... but .... if you use a cast iron plate it will color the part being cleaned jet black......

I usually scrub the cleaned parts with a hose and a 3M pad... sun dry.... and spray with diluted Phosphoric acid....... available as metal prep in body shops..... sun dries to a flat grey...... makes for an ideal surface prep for any kind of paint......

Do your process outside..... as the fizzling is actually hydrogen..... as in KABOOM......

Bob

[maple_leaf_eh]

Originally Posted by Bob Carriere

...

Washing soda is readily available in rural Home hardware stores.

...

I used a mild lye solution.....also from Home hardware..... but it is caustic and the drum can only be dumped on a heavy rainy downpour.

...

if you use a cast iron plate it will color the part being cleaned jet black......

...

What brand is the washing soda? Arm & Hammer is "So Clean, Super Washing Soda", and supposedly Walmart, Zellars and Canadian Tire sell it. Pfft! None on the shelf or in their on line catalogues. I was planning on visiting Home Hardware and Tractor Supply Company next.

So you make a solution of lye and washing soda? Sounds like a chemistry hazard in-waiting.

The colour is a good tip. The plates I have are ordinary carbon steel. Colour is not so much an issue because the parts will all get painted over. But removing the old finish and surface rust is secondary to getting the rusted swivels unseized. I will try lying them in a shallow pan with holes for solution circulation. Saddly, most of them are crusty with wood fibre or pits. The hardware is important to the project because some are odd little short and coarse thread woodscrews. [I'm stripping circa 1946 C No.7 .22LR rifle chest hardware from derelict chests for resale on the collector's and No.15 sniper rifle chest reproduction market. Special deal for any MLU'ers who want a set.]

I am going to politely decline using stainless steel. A few of the forums I read talk about hexavalent chromium compounds released by reverse electrolysis of stainless (anyone remember Erin Brockovich?).

[Mark Sierant]

Built a Soda bath the other day and decided that the more more power you put in the quicker the job will be done and placed a filthy weapons carrier bellhousing in the tank. I have acces to large deep cycle batteries as used in telephone exchanges so I built a string that could deliver 48 volts and 100 amps. Well all went well at first it took about one minute for my 60 litre tank to look like a foaming cup of coffee. I left it to run for about 1 hour when I returned the water had dropped two inches and was close to the boil. At this point I decided to pull the plug on my experiment. Silly me I removed the negative from the work only to be thrown a couple of metres in a bright flash and huge bang. As I removed the lead it drew a large arc igniting the Hydrogen being given off by the soda brew. It was well ventilated but I was still producing enough gas for a good blast. I think in future I will reserve this sort of power input to a 1200 litre tank I intend to buy.


BE CAREFULL RESTORERS

[Snowtractor]

...as HOMER would say, hope you're alright and still have all your hair.
Watched discovery channel last night and there was a blurb on Hydrogen. It said it had 100 TIMES MORE ENERGY than gasoline. They filled up 2 party sized ballons , one with straight oxygen and the other with hydrogen. Then they used a very long pole ,with a match on it, to light the ballons. The O2 went bang, neat , the H went "BOOM" and shook the camera about 30 feet away. Impressive, and dangerous, more so if in a confined area.
Sean

[Alex Blair (RIP)]

Mark...
Sean probably has lots of experience about explosive gasses and would be the first to comment on your story...
Probably could tell a story or two on explosive liquids of the 100 proof ,homemade variety....
Anyway ,how did the bell housing turn out..??

[Snowtractor]

Originally posted by Alex Blair
Mark...
Sean probably has lots of experience about explosive gasses and would be the first to comment on your story...
Probably could tell a story or two on explosive liquids of the 100 proof ,homemade variety....
Anyway ,how did the bell housing turn out..??

Easy there big fella, you being from Ottawa " land of the hot gases" I think I stand in good stead.
Sean

ps: hiccup

[Bob Moseley (RIP)]

To Mark and All Restorers,

Remember the fable of the Tortoise and the Hare.

The golden rule I always impart to my team of restorers is "these vehicles are 60 years plus old, work at their speed". I would rather have someone take days to remove a rusty stud than have it shear off and then spend the next few days drilling and tapping to replace it.

Mark, you were very lucky.

Bob

[Max Hedges]

Sounds like a bit of Russel coming out in you again, old mate. l did hear of one bloke put a big dint in his shed door in town.

Max

[cmperry4]

I was reviewing this thread with an eye to setting up an electrolysis rig and figured Arm&Hammer Washing Soda is the most likely and readily available product hereabouts.

Here's a link that lists all a whole lotta N.American household products that use sodium carbonate:

http://householdproducts.nlm.nih.gov...tbl=chem&id=16

I don't see that CLR stuff they're always trumpeting on TV - I got some to clean the rust stains in the toilet - expensive. Haven't tried it yet.

Note that the Arm&Hammer is >= 86% concentration, but that Prestone cooling system cleaner is 90-98% (along with some other potent ingredients)

I also have some of that commericial grade caustic soda stuff for cleaning coffee pots - it does brilliant job on my coffee thermos - but nasty to use, fine powder goes aerosol when disturbed, not nice to breathe. It would probably be great for rust removal, too.

[cmperry4]

If any Canadians are planning to set up for electrolysis, nip over to your Canadian Tire store and look for a nifty 75-litre (about 20 gals) heavy plastic round tub with rope handles they have on for a whole $9.99 - at least here in Winnipeg they did - I picked one up the other day (along with some Arm&Hammer washing soda) and figure it should do nicely. It's a little over knee-high and about 2 feet across at the top.

[Lynn Eades]

I'm no expert here but on hydrogen embrittlement, If you have an item that has been chrome plated , and you re chrome it you will severely weaken it as the process brings hydrogen to the surface of the metal which weakens the metal just as bringing nitrogen to the surface toughens it as in "nitriding"- dont re-chrome structural stuff like suspension/steering components.
Phosphoric acid is a food preservative. it is very good for cleaning ferrous metal (steel) Its probably the active agent in the HPsauce. If your going to use it talk to an industrial chemist first.
In an Impco book I read an article about how important it is to have good heat transfer from an engine block to the coolant, direct rather than through a layer of rust scale. The article reccomended cleaning the engine block out with muriatic acid, Which I understand is a particular strength of phosphoric acid to which an inhibitor is added to stop the acid continuing, once it has broken down the scale. I found it worked very well.
If you set up an acid bath with phosphoric, dont put cast iron or high carbon steel in it or every thing you put through it after that comes out black.
The great thing about any of the methods used in this thread is that they chemically stop the oxidation process whereas the purely mechanically process of blasting doesn't.
My carrier with its particular type of steel floor was quite rusty, the blasting took hours and hours because each little rust hole seemed to turn into a rust cavern inside, and although it was painted straight away the rust has re appeared. Because this has proven to happen quite a bit, I now like to combine mehanical and chemical cleaning. ....A great thread, Thanks guys.

[Bob Moseley (RIP)]

Hi all
As this thread has again been visited I thought I would have another look over it myself. I'm very pleased and proud of all the responses since it began in February 2003 and through our illustrious Spinning Ball, it created the Restoration Forum. Keep the tips coming.
Bob

[cmperry4]

Got my 20gal/75 L tub full of water, got a nice clean steel rod (from an old stair runner, I think), mixed it up, hooked it up and works like a charm. Rust sloughed off an old battery tray like algae after an overnight session.

But here's the question: I bought a box of Arm&Hammer washing soda, which is 3 kg, or 6.6 lbs. According to Bob, he uses 1 lb/450 ml of soda to 4.5 litres (i.e. 1 gallon) of water, which in my tub would require 7.6 kg or 20 lbs of soda. Another online source http://www.bhi.co.uk/hints/rust.htm says 1 tablespoon soda per gallon, which for 20 gals, would be about a cup and a half. I dumped in the whole 3 kg box, thinking it wouldn't be enough, but it seems like more than plenty- the reaction just fizzes away nicely.

Update: This with a 12V, 10-amp trickle charger, which is indicating 3-4 amps as it works.

So does anyone have the definitive proportions of soda to water? Or is it like martinis, mix to taste?

[SteveJ]

Hi this is a great thread. I am going to try the electrolysis method.
I used myriatic acid soloution to clean an M38A1 fuel tank. It ate the rust instantly (wear a mask and goggles) and discovered every pinhole or potential pinhole in the tank. After a good soaking (15 min) I flushed it out with copious ammounts of water and sloshed it out with methyl hydrate. I repaired the pinholes and the tank is working great to this day.

Just a note on phosphoric acid, I used to work in a chemical fertilizer plant many years ago and this acid was used to make the fertilizer. Nothing rusted. The acid tended to solidify into a kind of muck and if you left your shovel stuck halfway in it for a couple of days and then gave the handle a pull the blade would snap off clean at the level of the acid mud. It really embrittled the steel.

SteveJ
43 GPW
52 M38CDN W/W
53 M100 CDN

[greg anderson (RIP)]

Can someone kindly point me to the discussion which I believe was on this site concerning the removal of rust by electrolysis using baking soda?--molasses etc.- thanks

[grant fincher]

Look back to a thread started by Bob Mosely on the 17th of August this year. I'm sure you will get the information you need as there is 2 pages of different methods listed.
Good Luck

[Barry Churcher]

Greg, you can give this site a look also.
Cheers,
Barry

http://www.stovebolt.com/techtips/ru..._derusting.htm

[greg anderson (RIP)]

Thank you both