First attempt at hydrolysis rust removal

[AES]

Crikey Mel! From just looking at the "gunge" left over from my own de-rusting I wouldn't ever consider siphoning it! I just pour it into a big bucket through an old nylon mesh filter with lots of water from the hose and put the remaining sludge into old tissues and newspapers for throw away.

Hope you're really OK now.

AES

 

[Mel769]

I feel fine now thanks; it really does go right through you thou, rapidly.

 

[johnbaz]

I had a go at cleaning some old coins in a little setup, As an anode I used a piece 15mm copper water pipe that I cut out and flattened, I used a low amperage car battery charger, It did the job Ok-ish

The coins had, I believe been underwater for a couple of hundred years so were badley eroded!!

I don't know why but some of the coins turned the electrolye yellow, Othe made it go brown!!

Brown!

Yellow!!

The coins before..

And after!

There was still some verdegris on some of them!!

By the way, I also tried some aluminium as an anode but it melted!! :shock:



John

 

[Mel769]

Apparently you should avoid using copper as a sacrificial electrode as it turns the piece to be cleaned copperish (as you have found). If you use steel it tends to cover the piece being cleaned with black magnetite and this should be removed fairly quickly. Ive discovered a good lotion to remove this magnetite can be made by mixing baking soda - toothpaste - and water, then give it a scrub with a green kitchen pad. It does a fairly good job of removing the black stuff. I have just completed a clean up of an old iron fire grate and is looking good, I will post some photo's tomorrow. 8)

 

[Mel769]

Here are some before and after pics of my fire grate for anyone who is interested; after an electric bath and a bit of blacking polish its looking alot healthier.

 

[blackrodd]

I this system better than white vinegar?
Regards Rodders

 

[dickm]

Here are some before and after pics of my fire grate for anyone who is interested; after an electric bath and a bit of blacking polish its looking alot healthier.

Blimey, that must have been some bath!!! Or did you just adapt your swimming pool??

 

[MCB]

I've used RESTORE products from Shield Technology with a great deal of success

It doesn't require electricity - just leave in solution (longer the more rusty it is )

It's freed screws that were rusted solid for me


MC Black

 

[chaoticbob]

I this system better than white vinegar?
Regards Rodders

Vinegar, being an acid (albeit a weak one) will attack the underlying iron to some extent. That may or may not be a problem. Electrolytic reduction 'deals' with the rust by converting it to other iron compounds - exactly what depends on pH, voltage, current density and the phase of the moon I dare say. Electrochemistry tends to be messy as shown by the pics of 'soups' in this thread - but the main advantage of the electrolytic derusting method AFAIK is that there is zero chance of attacking the base metal further than the rust has already done.

Mel, glad the intestinal effects were transient! Actually, thinking about it, all you had in there was sodium and carbonate ions from the soda crystals and iron - not a deadly combination taken in moderation.

I'll get me (lab) coat.

Robin

 

[Mel769]

I this system better than white vinegar?
Regards Rodders

I have found that using white vinegar does a great job, however there are so many variables including the type of metal being treated, space/time ect ect. I have found that while vineger works well it can turn certain metals a dull greyish colour For comparison, you can see below two lawnmower blades that were heavily rusted. The one below was treated with vinegar for about 3 days, the top one with electrolysis for 1 day.

 

[woodpig]

You can also use citric acid but that eats into the surface as well leaving a dull surface.

If you have a battery charger washing soda is very cheap in the supermarkets and safe to tip down the drain afterwards.