Jump to content
I Forge Iron

Rust Removal


Recommended Posts

Hello all,

I was reading the forum the other day and stumbled onto a thread talking about removing rust from tools. This thread was specifically talking about a small anvil. Various methods were discussed and I mentioned electrolysis for rust removal.

I have personally used this method many times and it works great. It will also take off old paint and other impurities from the surface down to bare metal.

There are many good links on YouTube that demonstrates what to do. One of my favorite designs is in this link.

Hope this helps someone some time.

Thanks all for reading.
Link to comment
Share on other sites

  • Replies 55
  • Created
  • Last Reply

Top Posters In This Topic

You have convinced me to try this on the anvil when it arrives, does look like an extremely good way to remove rust! Cant seem to find the arm and hammer washing soda here in the UK but did find something called Soda Crystals which according to the ingredients contains Sodium Carbonate Decahydrate greater than 30%, does that sound like the same sort of stuff??

Link to comment
Share on other sites

I'm not sure. You'd have to try it I guess on a sacrificial piece of metal.

I have heard of people making it from baking soda which is sodium bicarbonate. I'm not sure the process but I believe if you heat up sodium bicarbonate it will become sodium carbonate.

I'm sure YouTube might be a good resource as well.
I know in baking, dough rises as the bicarbonate becomes carbonate.

Good luck with the anvil resto.

Link to comment
Share on other sites

Alright, I looked on the box of laundry booster and it just said sodium carbonate. Dunno if your stuff will work or not. Sorry I can't be more helpful than that. You might have to do a little leg work or just try what you have out. Be sure to post a few pics of the anvil when you are all through.

Link to comment
Share on other sites

Wish I spent more attention in chemistry class right now!

Sodium Carbonate is Na2CO3
Sodium Carbonate Decahydrate is Na2CO3.10H2O

Which means in the dehydrate there are 10 water molecules to every sodium carbonate molecule.


Good old google tells me the molar mass of sodium carbonate is around 105g/mol and the molar mass for the decahydrate is 286g/mol which means you need around three times as much but in essence it is the same thing!

Link to comment
Share on other sites

You guys are overthinking electrolosys. The purpose of the sodium bicarb, salt, vinegar, etc. etc. is to make an electrolyte, plain water isn't a conductor. Adding almost anything to make water a conductor is all it takes.


Sodium bicarb has become a kind of standard because it's about as non-toxic as it gets and makes a good emergency dunk in the shop.


Frosty the Lucky.

Link to comment
Share on other sites

having said that though frosty, there are some things that erode the steel, and not just the rust, caustic soda, in the same ratio, erodes into the parent metal, and so does salt water.


Maybe not use corrosives in a concentration to damage the piece? Two points, I sort of assumed a person wouldn't use a dangerous concentration of corrosives. Then there's the process of electrolosys, while the current is flowing oxydization is reversed and additional corrosion isn't taking place. Turn the power off and you're just steeping your work in a dilute water and? solution.


All it takes is enough, whatever you like, in solution to turn water into a conductor. When you're finished remove the work from the electrolyte, neutralize, rinse, dry and treat the work against rust. Not significantly different than any other rust removal process, try leaving a sand blasted piece exposed and see how fast it rusts.


I'll try and be more clear in the future, and lower my expectations of commen sense.


Frosty The Lucky.

Link to comment
Share on other sites

I've been using this method alot, but I wonder, how easily does hydrogen embrittlement occur? I thought it took months and years in a pressurized state to get that, hydrogen tanks for example.

Depends on the alloy, temperature and pressure and can occur quite quickly (as in minutes) with high strength steels, low temps, high acid concentrations and high pressure. At room temps and atmospheric pressure it is much slower, but NACE (National Assn of Corrosion Engineers), suggests only a four hour window between acid treating and starting to bake the hydrogen out.

Link to comment
Share on other sites

I remember this subject coming up on other websites. The one thing that stuck with me was DON'T use stainless steel as your sacrificial anode. The chromium can form into it's hexavalent variant, a nasty carcinogen, turning your vat or tub into a container of HazMat.  Okay a little over the top, just err on the side of caution for which material you use for the electrode.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...