Electrolysis rust removal question.

Is there any truth to the fact that molassis and vinegar cause metal embrittlement and electrolysis doesn't?

 

Neither molasses or vinegar is capable of altering the internal structure of metal. What, if any effect they have, would be limited to the outer surface, for the duration of the exposure.

 

Why not use a product that's save to you and the environment?


Just add water or use it in gel form.

http://www.bilthamber.com/pro-introduction.php?cname=Corrosion%20Removal&name=deox-C

 

I used reverse electrolysis on an entire car body, I must say I was impressed with what was removed without harming the already compromised metal. This was done in a well ventilated barn, and foloks were instructed to put cigarettes out, etc, before going close to it. http://www.forwardlook.net/forums/forums/thread-view.asp

---John

 

Try this link again-
http://www.forwardlook.net/forums/forums/thread-view.asp?

 

There was another post here on this subject and someone had cleaned up a Hemi in molasses. The crank broke into many pieces after the rebuild and it was attributed to the molassis treatment - acid in the molassis and hydrogen induced embrittlement. Is this an urban myth?

 

I've been derusting parts with electrolysis for the last few months. I started with rebar anodes and then moved up to steel plates to get the amperage up. Of course, the steel got covered with crap pretty fast and the amperage went down. I had to clean the anodes several times to keep the amps up.

Then I read somewhere about using carbon anodes. I had some large carbon brushes out of a huge industrial generator handy and used them. What a difference! No cleaning required and the amperage stayed up for the whole derusting process. My brushes were fairly soft and did break down some leaving the water black, but as far as I know carbon isn't toxic waste. Hard carbon is supposed to be better, but what I had was free.

It appears that carbon works as well as stainless without the nasty toxic byproducts.

Mike

 

I do not believe that the acid of molasses is strong enough to cause it. One example does not a data-set make.

It can be caused by acids, but ones of much greater strength.

I suspect in this case, the crank was already compromised.

In any case, if it were not, and there was some embrittlement, it could have been alleviated by a bare-minimum time soak, and baking the crank afterwards. 400F, for a few hours would take care of it.

 

Wish that thread could be found but it seems they left it in the molasses for a year.

 

experiments derusting at higher voltages;

I used a small dc inverter welder and battery chargers in different configurations. The welder put out the most voltage but I was afraid to leave it running without being nearby. I used a car start charger set on start for high voltage. Also two chargers connected in series for doubled voltage.

The size of the anode matters I forgot to clean the anode often so higher voltage seems to compensate for that. Don't let it short out, I cooked one battery charger that way.
The plastic screen is a great idea to prevent shorts.

Thanks for the several good suggestions, I will try carbon anodes, [if I ever find big chunks of carbon] I could not find washing soda so I made mine from baking soda in an oven at 330 degrees [30 minutes on a cookie tin.]

 

This topic has been discussed on the HAMB before :
http://www.jalopyjournal.com/forum/showthread.php?t=324259&highlight=electroysis

I have to say I am convinced of the virtues of this method of rust removal over the acid based methods.

Electrolysis self regulates so that once the iron oxide has been reduced to iron and oxygen (which bubbles off to the atmosphere) the reaction stops . Not so with the acid based methods , it just keeps on eating away and if you leave it in too long you will observe fine pits in the surface where the acid has eaten out the carbon in the steel . This turns the material into more of an pure iron composition than the original steel. This is what makes it brittle.

As to the rusty hemi crank being cleaned in molasses and then disintegrating in the rebuilt engine it was fitted to, this is a similar story to one to related to me by a friend about an old motorbike crank/flywheel assembly. Same result.Disintegrated and caused major damage. Molasses is okay for static parts but you still have to watch to ensure that you dont leave it in too long . Anthing stressed , be careful. Also , you should protect non- rusted portions from contact with the acid. This is the beauty of the electrolysis method , it is selective.

 

Try looking in the swimming pool section of your hardware store. It's sold to lower the PH of pool water. Pure calcium carbonate.

Mike

 

Washing soda is not calcium carbonate, it's sodium carbonate. Sodium Bicarbonate with one less carbon.

Look in the laundry detergent section for "Arm & Hammer Washing Soda".

 

Sorry to confuse. What's available in the pool section IS sodium carbonate, I got the name wrong in my post, but the material is correct.

"Washing Soda" isn't available anywhere in my area except the hardware store pool section. Grocery stores around here no longer carry it for washing. I had to find another source.

Mike

 

big m what was the electroylsis rust removal under

 

washing soda is available at Ace Hardware...jack

 

Check with your welding supply house for Carbon Arc carbons -- they're 1/4" dia carbon rods. Should work well as an anode.

 

So, I've been playing around with this for the last couple of weeks, with some really good results.

Follow up question for those wiser than myself (just about anyone):
Are there any potential toxins when stainless, galvanized, or chrome are the cathode? Not that I'm aching to derust galvanized or chrome, but I'd like to be able to throw a hub in for derusting without removing the bearing races, things like that. Thoughts?

 

Stainless as the anode will produce Hexavalent Chromium (Chromium+6).

VERY DANGEROUS STUFF:

http://en.wikipedia.org/wiki/Hexavalent_chromium

DO NOT USE IT!

 

I thought perhaps that the direction of the reaction, the anode being sacrificial, would result in nastiness if using anything other than mild steel for the anode, but that the cathode would not react.

not trying to split hairs or do anything dangerous, I'm just curious.

 

Bump for the morning brains.
Is stainless as the cathode a problem too, or just when used as the anode?

 

Anyone know how long you can use a batch before you need to re-mix the solution? I tried this yesterday and like the results.

 

One last try

 

from what I've read on another site, I think you can use the solution until it until it just gets too dirty to work with. You lose water via evaporation, but the sodium carbinate should remain.

 

Bump, anyone know the answer to this old thread post? I just ran across it and would like a know also.
Herschel

Sent from my cell phone when I shoulda been working, using the H.A.M.B. mobile app