View Full Version : What to soak 1-2-3 blocks in to neutralize rust?

07-23-2009, 11:40 AM
A friend gave me 8 1-2-3 blocks that had heavy rust on them, not everywhere, but bad enough. I sand blasted them and then was able to pick 6 that would grind to usable condition.

I have one side left to grind and now need to soak them when done to stop or control the rust. I was planing to soak them in kerosene for months hoping they would soak the kerosene into the rust that may remain in the drilled holes that the blasting did not get.

Sooo, give me some ideas to pick from.

07-23-2009, 12:21 PM
Carl, I'm a big fan of Evap-O-Rust, which is some kind of chemical chelating agent that dissolves the rust off without harming the underlying metal (it doesn't convert good steel to an oxide layer like phosphoric acid does).

It's relative inexpensive at Harbor Freight.

07-23-2009, 12:54 PM
That sounds good since I have already ground the outer surfaces. There is some heavy pitting on the ground surfaces but in small areas that won't affect the use of them. I do want to stop the rust from causing more trouble. If I have to keep them soaking until I die and only pull them out to use them I would not mind but I would rather not have to do that.

I will do a google for Evap-O-Rust.

Any other ideas?

07-23-2009, 01:19 PM
I used simple phosphoric acid to treat an old Bridgeport vice I was refurbishing and it worked great. Bought it from Lowes. Any rust is converted to a phosphate and is very similar if not the same thing as Parkerizing on gun barrels. Very long lasting as well. Have a look:



I think a set of blocks with that coating would be awesome ;)

07-23-2009, 01:19 PM
$20/gallon. Use the perpetual 20% off coupon:



07-23-2009, 01:32 PM
If there is an advance Auto parts nearby they carry a phosphoric acid based remover that works really well, does so quite rapidly and is the best thing I have found, about $6 for a 32 OZ. bottle. I use this stuff on just about anything that rusts because it not only removes the rust but leaves a rust resistant coating.

07-23-2009, 01:59 PM
Carl...Have you ever used Kroil? I have had pretty good luck with it on badly rusted parts. It seems to turn rust into mush, which is easily removed. When removed, it does not rust up badly as untreated stuff does. Just my opinion, FWIW.

07-23-2009, 02:39 PM
I got 5 B&S setup parallels, each 1x2x12. They had been left in a storage room, and while still in pretty decent shape, they had some blotches of rust. They were being placed in a scrap bin when I found them (along with some other goodies). I paid what the scrapper was going to pay and brought them home. Put them in a long plastic pan I keep on hand for just such occasions, added a 5:1 mixture of Phosphoric Acid (in the form of common Concrete Etch) and let simmer for about 20 minutes. Rust gone, other material seems untouched and is dimensionally as accurate as I am capable of measuring. After dry and wipe down cleaning, I then wipe with "oily rag" to apply a light R&O oil and let sit a bit. Finally wipe with clean rag (still leaves very light oil film) and place in cabinet with felt lining sprayed with rust preventative for just that purpose (long long ago, still seems to work well).

07-23-2009, 03:46 PM
There's not much rust left, just what I couldn't bust loose inside the holes. The surfaces are ground now and the pits on the surface is what I need to control because the rust may spread.

I have read some posts that the phosphoric acid may turn the metal blackish, is that true and does that stop future rust?

I am leaning toward the Evap-O-Rust but it would take two life times to use a gallon up. Maybe not.

07-23-2009, 04:15 PM
The Phosphoric acid is the active agent in rust "converters" that both dissolve rust and change any remaining to a rust resistant coating, not rust proof but certainly much better than just bare steel. The Phosphoric acid will stop rust from forming and/or growing in any pits where there may be some remaining and it does indeed work as advertised, it has been around in one form or another for many years (OSPHO being the most popular form) and is used in industrial applications and also is quite popular for auto body work.

07-23-2009, 06:09 PM
I'm a great fan of the electrolytic rust removal process, simple and quick


07-23-2009, 06:35 PM
I'm a great fan of the electrolytic rust removal process, simple and quick


If you can't find the arm and hammer washing soda, hit the local pool supply and pick up the Ph plus Sodium Carbonate

And for the odd time that you need to match that rusted pile with the shiny part you just made

07-23-2009, 06:51 PM
Evapo-Rust does indeed work, but something has to be done with the resulting surface or it will rust up again immediately.

07-23-2009, 06:54 PM
In my case, I've seen steel get a gray coating, depending on the alloy. Cast iron also gets that coating. In both cases it's generally easy to remove, though I'm told that it inhibits rust. However, I've had no rust issues with any of the myriad of stuff I've run through a mild acid bath. Then again, I'm in Phoenix, so your mileage may vary.

I've used the EvapRust and still got most of a gallon. But it "dies" relatively quickly and costs much more per area "treated" than the Concrete Etching solution. So I save it for very sensitive stuff I'm trying to save. For instance, a Albrecht chuck with rust on the bell and body, but ok inside.

07-23-2009, 08:35 PM
I think I'll grind one of the two rejects and use phosphoric acid on it to see how it reacts. Maybe that will be the route to take. I don't mind the patina if it looks ok.

What amazed me is how square they still are and how well they ground considering.

07-23-2009, 08:43 PM
If you want to neuter it - castrate it - that should deactivate it.

My dog was bright and shiny before he was "done" but got pretty rusty afterwards.

Cat just sat around "missing himself".

Both got fat - real fat - obese?

Can neutering be the cause of obesity and diabetes?

Ever notice that dogs and cats don't hang out at "Maccas" - maybe they know something that we - me anyway - don't.

Perhaps I'm just getting rusty.

Wonder why?

07-23-2009, 11:18 PM
I suppose if you grind the faces of the 123 blocks, they won't be 123 anymore- but they might still be square and perfectly usable for setup, etc.

The old trick as I've heard it is to set parts in coca cola overnite. Phosphoric acid is one of the ingredients, or so it used to be.

07-23-2009, 11:37 PM
Make sure that you clearly mark them so that you do not get a nasty surprise by mixing them with a standard size block. I have a couple of cheap beater blocks that I have marked with yellow paint inside the holes so that I don't accidentally use them as precision blocks.

07-24-2009, 12:05 AM
I plan to keep them in a box together and after I am dead if someone is dumb enough to use them without checking the size that's their problem. I'll even keep the unground pair with them as a warning of sorts, unless I grind them.

Yes, the only reason I salvaged them is to have 6 blocks of the same size to support work with. I have two other sets of 1-2-3 blocks and the pairs don't match. One set is to size and the other is undersize. Now I have 6 same size blocks to use.

07-24-2009, 06:33 AM
You can convert them into 25 50 75 blocks Carld, one thing you might think about is "Blueing them in the oven and oil quenching them.

Regards Ian.

07-24-2009, 11:20 AM
I use evaporust often, and occassionally electrolysys. I don't like the patchy iron phosphate coating that the acid leaves. To protect evaporust clean material from "flash rust", dip the washed steel in clean evaporust and let it dry. I've had some project siting around for 6 months in this state with no problems.

Like any tooling, a light oiling revisited occasionally seems to stop rust.

I don't know if it changes the dimension materially, but what about a black oxide -"home brew" method?