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Seeking advice on cleaning up an old anvil


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Wondering if using 'OSPHO' or another similar product to convert surface rust on an anvil would be detrimental in any way ?  Is there a particular, accepted procedure for cleaning up these things?  Anything that should definitely not be done?  Thanks.   

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Wondering if using 'OSPHO' or another similar product to convert surface rust on an anvil would be detrimental in any way ?  Is there a particular, accepted procedure for cleaning up these things?  Anything that should definitely not be done?  Thanks.   

Don't use a grinder.  'OSPHO'  is unfamiliar to me but I've used "Naval Jelly" on the body of an anvil.  Rust converters on the face may not be a great idea. The residue could contaminate your work.  Most people suggest using the face as is after a vigorous wire brushing if really terrible, but otherwise just use it. 

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Easiest method: electrolysis

before: IMG_0337_zpsrrudbebo.jpg

after: 3FAD416A-DDFB-4D99-A7D8-1E2FCDC83AE5_zps

Here's a Youtube video outlining the process, it's really easy and inexpensive

https://www.youtube.com/watch?v=54ADeB6V1rQ

I found the same Arm & Hammer laundry soda he used in the video at Menards for $3.25 a box locally and splurged for 4 rebar grounding straps which I used to wire the rebar sections together (I zip tied each section to the tank using the same hole locations he used in the video for his copper wire).  I used a Schumacher XC6 battery charger from Wal mart I had lying around, the trick to getting it to "see" the electrolysis tank as a battery was to generously wrap the anvil in steel wire (NOT STAINLESS).  I originally started by running a single wire through the hardie hole and out the pritchel hole before I twisted them together and attached it to the ground... but the charger didn't detect a load and would not start. I ended up making 3 larger loops around anvil which I twisted together and connected to the ground lead which then worked fine.

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If someone is going to use the electrolysis method for the first time and doesn't yet have a battery charger, the newer chargers don't work well as Yuppiejr pointed out.  If you have to buy one, get a manual model, not the automatic.  Charge rate needs to be probably 6 amps or more.  The automatic chargers look to see if an actual battery (load) is attached and if not, will not run.  The manual chargers just shoot the current to the electrodes.  I had a small manual 3 amp charger and it wasn't large enough.  Bought a new manual one, runs 6 amps I believe, and works fine.

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Honestly as long as I had enough wire wrapped around the anvil the modern Schumacher charger worked fine for me, and I actually had better results running it at a 2 amp charge rate (the "snowflake" trickle charge mode) versus the fast charge mode which is 6a for a shorter period of time with 4 sections of rebar in the tank.  

What I'm not sure about is if the failure to detect a battery/load with the automated charger indicated a condition that would not have allowed the process to work correctly even if the charger just went ahead and fired up.  Simply running a loop of wire through the hardie & pritchel holes and twisting up the ends did not provide enough contact with the anvil for the charger to think it was connected to a battery.  I had the same issue with a Battery Tender wall-wart trickle charger that would not detect the "battery" tank load but followed the same pattern of behavior as the Schumacher and started to "charge" after I wrapped the anvil in more steel wire.    

 

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Ospho or Naval Jelly (N J) are both phosphoric acid compounds and work very well. I've gotten excellent results from Naval Jelly on  very heavily rusted things the one that jumps out right now is a small set hammer head. I found it in the basement of the Seward Machine Shop when it was being liquidated as an estate. That was a good pick. Anyway that little hammer head was so rusted the eye was closed and the entire surface was leaves of rust like a book.

I diluted the (N J) in water to about 1/3 and laid the hammer head on 4 plastic pointy ended thumb tacks I'd ground the points. The next morning, say 18+/- hours I rinsed it neutralized with dilute vinegar and rinsed again. The hammer head had been restored to as close to new as it was when it went into the basement, you can read the maker, size, weight and see the spot where a single chip of rust got knocked off.

If you follow the directions on the bottle and allow Ospho or (N J) to dry it leaves a flat black  phosphorous (oxide?) coating which is a perfect primer for painting and will protect the steel until it wears off.

I also have a gallon bottle of lab grade phosphoric acid and it does the same job however it lacks efficiency. I think both Ospho and (N J) have surfacants "Wetting agents" and (N J) has a jell agent to make it stick. Were I experimenting I'd look into Jet Dry or find a source of Sodium Laural Sulphate. (the ingredient in Jet Dry and other similar products, like: shampoos, dish soaps, dish washer soaps, laundry detergents, car wash soaps, etc. to make the product wet the subject.)

Regardless a covered, plastic bucket or tub with a solution of 1/3 dilution of (N J), Ospho or about a 10-15% solution of phosphoric acid is about as easy as derusting gets. WAY easier than brushing and the upside is dilute phosphoric acid is in the realm of fertilizer so haz mat disposal isn't a big deal or we wouldn't be allowed to use NJ or Ospho at all.

Just remember you must neutralize rinse and as soon as it's dry oil, wax or paint the project or it will rust almost as you watch. It's really pretty cool to see steel rust so fast but a spritze or wipe of something to protect it is easy. Heck, Pledge spray wax or Pam does the trick at least temporarily.

Frosty The Lucky.

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snip.......

I diluted the (N J) in water to about 1/3 and laid the hammer head on 4 plastic pointy ended thumb tacks I'd ground the points. The next morning, say 18+/- hours I rinsed it neutralized with dilute vinegar and rinsed again. The hammer head had been restored to as close to new as it was when it went into the basement, you can read the maker, size, weight and see the spot where a single chip of rust got knocked off.

..........

 

Frosty The Lucky.

Frosty, I don't know how you neutralized an acid (phosphoric) with another acid (vinegar which is acetic acid).  You need a base solution to neutralize the acid(s).  I use regular baking soda solution for these acids, then rinse well with water and dry quickly,

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 Lots of great advice here.  My personal opinion is to get some iron hot and hit it on the anvil.  The rust won't really matter.  If its just a matter of aesthetics, I used vinegar and a wire brush then a solution of baking soda.  Cheap and effective.  Then I wipe everything down with a rag that has vegetable oil on it.   

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Frosty, I don't know how you neutralized an acid (phosphoric) with another acid (vinegar which is acetic acid).  You need a base solution to neutralize the acid(s).  I use regular baking soda solution for these acids, then rinse well with water and dry quickly,

ARGHHHHH! Neutralize with Baking Soda. Thanks for back stopping my mistakes. I don't know what I was thinking, certainly not basic chemistry. Even MY level basic.

Frosty The Lucky.

 

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Mine sit outside year round. The rust on the face gets knocked off as soon as I use them. Then again, we only get 4" of rain a year......

I wouldn't take it down to shiny metal, as the rust forms a patina that actually helps to protect it. Rub it down, and use it.

Edited by BIGGUNDOCTOR
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  Brushing pool acid (use a plastic wash brush) straight out of the jug works very well too.  Just make sure you're downwind of the stuff and don't do it on your concrete driveway or you'll have to clean your driveway with the stuff to get the rust off of that too.  Stuff works in minutes.  Then just rinse it off and then rinse again in baking soda solution. If you don't do that you can watch the rust creep across as it dries.   Leaves a great finish for painting which you should do immediately or it will be completely coated in rust within 2 days, even with the neutralizing rinse.

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