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RUST REMOVAL

menace

Hot Rolled
Joined
Feb 6, 2005
Location
Upstate, N.Y. USA
I just picked up all the parts to convert my 9" SB C to an A. the apron is all rusty inside but the gears are cherry ,hence I bought this instead of a cleaner worn one . A friend said to put it in a pail of water with 1 tbs per gal of water of "wash soda" and place a couple of anodes in there as well and hook up the battery charger for a few hrs/day. The problem I have is can't find "wash-soda" in the store! This wouldn't be Arm +Hammer baking soda ,would it ? If not does anyone know a brand name ? The other question is the electrical connection, does the positive go to the Apron or the anode???? Or should I just take it apart and wire wheel it etc? This way is supposed to get where the sun don't shine, it would be nice to neutralize the hidden rust but I'm not about to guess how the process is done, if anyone could help with an answer, I would appreciate it! Thanks in advance!

Steve
 
NO..... Dont use the baking soda, will not be happy with the results.

Just keep looking for the Arm&hammer washing soda. My local store didnt have it but a little town just north of me did. They are owned by the same people.

Might even ask if they will order it for you. Also try the hardware stores in the area also.
The stuff WORKS. Just finished using it last weekend. Its amazing :D :D

Michael
 
The NEGATIVE cable clips to the part you want to de-rust. The positive cable goes to the sacrificial anode. (The anode WILL get sacrificed!)

Items with recesses will need to have the anode inside the recess.

If the item has holes, you can de-rust the inside of the holes by using steel wire as the anode.

I use "20 Mule Team Borax" with great results. I've also used the house brand washing soda from the Pathmark supermarket.

Keep the electrolyte warm for faster results.

There's an OLDTOOLS mailing list on the net, with a description of electrolytic rust removal in the FAQ section. (Search for that - don't have the URL at the moment.)

The "used" electolyte will cause stains. If you do this in your wife's dishpan, you will have to buy her another one!!!

Items come out with a soft black coating that you should scrub off with steel wool.

DO NOT put springs into the electrolysis tank. This includes springs on the clips of a battery charger. They will go brittle and break.

Any tool steel should be baked to get the hydrogen out of it after you remove it from the bath. Gentle baking, not enough to draw the temper! 200 deg. 1/2 hr. Do this before painting, japanning, waxing, or plating. I sometime rub bare steel items with Butcher's Wax or paraffin while still hot from the oven. Makes them look nice and keeps them from re-rusting.

I could go on and on about the advantages of electrolytic rust removal. The main one is that it is the only practical way I know to treat steel that has been exposed to salt or other sources of chloride ions. This is the only way to stop the rust cycle caused by chloride ions.

Geez, I better stop rambling. Suffice to say this is a GREAT process for anyone who llkes old tools or machines.

John Ruth
 
The washing soda is usually in the detergent aisle of the supermarket. Arm and Hammer makes it. Don't let your wife get hold of it, it's good for laundry apparently, as well. If this can't be found, baking soda will lwork, but not as well. Use some sort of wire mesh for an electrode; this works "line of sight", w/ one battery charger cable on the part (I think +), the other on electrode (I think -; current flows + to - generally, so I think this is how it goes... if you have more rust on the part than on the electrode after a few days, it's wrong :D ). If the part is surrounded by the electrode the rust will transfer from part to electrode thoroughly; if you just have a rod for an electrode, only a straight line from part to rod will get clean. 1 tbs/gal is correct. A friend of mine has used this extensively for rust removal on antique engine parts... it takes a few days for heavily rusted things... but it works extremely well, and leaves a nice fininsh. Much better than sand blasting or wire brushing.
 
Menace: when using the battery Charger the pos terminal will create Hydrogen gas, if you use a glass tub you will be able to see the Hydrogen bubbles flowing to the top, I dont know if a battery charger will have enough power to light the water on fire or not, but a friend of mine used 110 V in a tub of water and was able to light it on fire. the neg terminal will create Oxygen. just as a safty measure don't have sparks or open flame around(no smoking :D .)I have made Hydrogen gas and it explodes nicely. I have never tried making Hydrogen with 12 v so I don't know if it will create enough gas to light or not.
David
 
I use METAL ETCH, which I get from a local chemical supply house. It's advertised as a rust remover. It's 10% phosphoric acid - dissolves rust but not clean steel (iron). Item must be thoroughly degreased first. I then rinse in a baking soda solution to neutralize, dry, wire brush or buff, and then oil the surfaces (unless I am going to paint it). Does a very good job.
 
As 2LNDie said, you must attach the NEG (cathode) to the part and the POS to the anode which must be steel or stainless. Do not use galvanized parts for the anode. Never let the anode and cathode touch as they will short your charger. Some chargers will require a battery for a load hooked in parallel before the electrolytic bath. If you need to remove rust from the ways of a small bed then you should use flat bar stock as the anode. After my next project I want to try forming a cage around the part using stainless TIG wire. This will hopefully allow fewer setups as the process is "line of sight" between the anode and the cathode.

Washing soda or baking soda will work as the "salt" in the solution. It will form sodium ions+ and carbonate ions(2-)when dissolved into solution. Do not use regular table salt as it dissolves into sodium+ and chlorine- which mill make Chlorine2 gas. Chlorine gas will cause chemical pneumonia and/or kill you.

The nasty stuff that forms in the water is from a chemical reaction that forms rust at the anode, not from the part. If you get the charges reversed it will do this to your part. The cathode(your part) is negatively charged and attracts positively charged ions. There are two reactions that take place at the cathode. The important one is an oxygen- in the rust combining with a sodium+ atom. You no longer have rust. The other reaction is the combining of hydrogen- ions and hydrogen+ ions which form hydrogen2 gas. This hydrogen will be evident as bubbles in the water. Please do this outside and don't smoke or create sparks.

I will post pictures of my Cataract lathe after this weekends rust removal. I will be using a plastic trash can as the container because I couldn't find an appropriately sized container for the bed. It is possible to use heavy plastic liner in a box or cavity but the trash can is easier. Thanks to Dr. Judy Chu who was my chemisty instructor and to other people who have posted to various forums.

Richard
www.homemachineshop.com
 
Ive used this method and it works well. You can also use tea (tannic acid) and you dont need the electrolosis bit. Just soak for 6-8 hours. Vinegar also works.
 
I guess the only thing I'd add is anything made of bronze, brass, aluminum or copper on the part you're cleaning will be attacked by the process.

I did my old SB 10" with electrolysis, worked great- it definitely helps to have as many anodes as you can fit into the bath, surrounding the part being cleaned and get the current up high enough to make the water fairly hot. But don't sweat setting up the anodes too much, they'll dissolve along the way no matter how hard they are. I used a stainless spring and a couple strainless pipe clamps my brother gave me, the spring eroded to a little sliver and the clamps eroded nearly into pieces.

For heavily crudded/thickly painted surfaces, you may want to rig the bath to run overnight, so a hefty power supply will make the job lots easier. A battery charger is OK, the bigger the better- try to get 10-20 amps or so going through the bath, more if you can- it'll move the job along.

And FOR SURE remember to cut the power before sticking your hands into the water- you'll be shocked if you don't.

Gregm
 
I've been using electrolytic rust removal for close to ten years. It has served me well, but there are some jobs it won't handle very well.

I've demonstrated the method to a number of groups; but, because some folks were still making mistake--such as reversing the connections from the power supply--I wrote a handout that summarizes my experiences with the process.

It's not Web friendly, but if you print it out and read it all, you might find the information useful:

http://users.moscow.com/oiseming/rustdemo/rustdemo.htm

Some day I hope to add pictures, but first I need to get a round tuit.

Regards,

Orrin
 
Having aquired a number of 5C collets & step chucks together with d1-4 adapters (suitable for my Colchester Student 1800) that had been left ouside for some time, I decided to try the vinegar method.

Am very pleased with the result.After a rub with scotchbrite, I rinsed & dried (with heat) the items & applied Plus Gas penetrant followed by a coat of rust inhibitor.

About 12-18 hours soaking seemed about right with a rub with scotchbrite & rinse halfway through.

There is some pitting on a few of the most badly corroded items, but plenty of the original working surfaces left to still function effectively.

I would be reluctant to use corrosive chemicals on castings as the porosity would retain more than enough to cause problems in the future.

Should think that the best thing to do with a rusted casting would be bead blasting.

Now need a drawbar for my lathe.

Don

[ 03-13-2005, 03:32 AM: Message edited by: Don UK ]
 
Not on the electrolytic topic, but I have used household cleaners such as Lime-A-Way and CLR to remove rust from small parts and tools.

I assume these are phosphoric acid based, and do a good job, but you really need to watch your parts!

Working time on small items is measured in minutes or even seconds...you don't want to soak them for hours. I was cleaning some small hex sockets that had rusted in a damp toolbox. These were chrome-plated sockets, US-made.

I was using the solution in baby-food jars and doing a few pieces at a time. I forgot about one batch for about ten minutes, and not only was the rust gone, but so was most of the chrome.

One night I forgot to cap one of the jars, and the next morning, everything within a 12-inch radius of the jar was beginning to rust. Potent stuff.
 
Ridrust seems to have a following. And probably a place, although it's pricy. I've never tried it.


I use Savogran Crete-Nu, which is phosphoric acid.

The CLR and related stuff USED to be phosphoric, but now the stuff I've checked was no longer phosphoric.

I have had very good results with phosphoric. And it seems to have no tendency to corrode other things in or around the shop.

I was not pleased with electrolytic "rust removal". There was a thick black coating left after treatment, that stuck on very hard. By the time I removed that, I might as well have scrubbed the rust away.

I know others seem to get great results with electrolytic. More power to them, I couldn't get it to work in a way I was happy with.

Nothing I did that way came out gleaming, or even close to it. Most had gray to black 'stuff" on it, it seemed to be a "color changer" but not a "remover".

Plenty of stuff gleamed, or was close to it, using phosphoric. Rust actually was removed.
 
The NEGATIVE cable clips to the part you want to de-rust. The positive cable goes to the sacrificial anode. (The anode WILL get sacrificed!)

Items with recesses will need to have the anode inside the recess.

If the item has holes, you can de-rust the inside of the holes by using steel wire as the anode.

I use "20 Mule Team Borax" with great results. I've also used the house brand washing soda from the Pathmark supermarket.

Keep the electrolyte warm for faster results.

There's an OLDTOOLS mailing list on the net, with a description of electrolytic rust removal in the FAQ section. (Search for that - don't have the URL at the moment.)

The "used" electolyte will cause stains. If you do this in your wife's dishpan, you will have to buy her another one!!!

Items come out with a soft black coating that you should scrub off with steel wool.

DO NOT put springs into the electrolysis tank. This includes springs on the clips of a battery charger. They will go brittle and break.

Any tool steel should be baked to get the hydrogen out of it after you remove it from the bath. Gentle baking, not enough to draw the temper! 200 deg. 1/2 hr. Do this before painting, japanning, waxing, or plating. I sometime rub bare steel items with Butcher's Wax or paraffin while still hot from the oven. Makes them look nice and keeps them from re-rusting.

I could go on and on about the advantages of electrolytic rust removal. The main one is that it is the only practical way I know to treat steel that has been exposed to salt or other sources of chloride ions. This is the only way to stop the rust cycle caused by chloride ions.

Geez, I better stop rambling. Suffice to say this is a GREAT process for anyone who llkes old tools or machines.

John Ruth

.....There’s no hydrogen to “get out” of the part. Once hydrogen discharge potential has been reached in the tank/cell the hydrogen ions either reduce the ferrous material or create molecular hydrogen, which makes those nice scrubbing bubbles of gaseous hydrogen that rise to the surface. There are a few disassociated hydrogen ions in the electrolyte solution but only while current is flowing. Once you cut the power those bond with the nearest oxygen and become just water again. There’s no extra hydrogen left over or otherwise on the metal, it’s just water.

Putting it in the oven is accelerating the air drying process and making sure it’s dry in all the nooks and crannies. It will retard the normal ferrous oxidation process but as you note, you still have to put something on the surface. Not putting it in the oven will not affect the end result. The important things are making sure it’s dry and the surface is protected.
 
I am with JST on this. I tried electrolytic several times. Too fussy, mixed results.
I use Evaporust it works it’s not messy, it doesn’t affect anything that is not rust. You just submerge the part, oily or dry, and take it out the next day...or week. Nice and clean. No drama.. somewhat expensive.
Amazon sells a similar product which is concentrated. I gallon makes 16 for $54 shipped. Now I use both.

I have rebuilt almost50 lathes and mills in 20 years. This is what works for me.

Rex
 








 
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