Update -- Rust Removal for the Little Stuff

[Tom LaRussa]

I have found that electrolysis is the best way to rid large chunks of metal -- plane bodies and froggies for example -- of rust.

But what about the little stuff? All those screws, knobs, and the like that hold the plane together?

Well, here's one solution I've come up with.

Supplies:

1 quart-sized glass jar with lid
1 cup powdered citric acid
2 cups white vinegar
some rusty bits and pieces of planes -- washed to remove grease and big chunks of junk

Dump the citric acid and vinegar into the jar, screw on lid, shake vigorously for a few seconds.

Add rusty stuff

Replace lid, but do not tighten all the way, as this will produce a bit of gas. (I have no idea if the gas would/could ever build up enough pressure to burst the jar, but I think it's better not to take chances, as this stuff would make a pretty gross mess to clean up.)

Set jar aside for several days.

[Dan Moening]

Tom,

We certainly are gaining alot from your misfortune of shop time.

I really appreciate all that you share here.

Is the second picture after a few days of soaking?
If so, I'd have to say that it does an OK job for minor rusting but doesn't quite get the heavier scaley stuff that phospheric acid might. Would that be fair to say?

I imagine frequent shakings might aid in removal, eh?

How strong a solution of citric acid did you make?

[Tom LaRussa]

Is the second picture after a few days of soaking?
Nope, that's just after I mixed up the batch.



If so, I'd have to say that it does an OK job for minor rusting but doesn't quite get the heavier scaley stuff that phospheric acid might. Would that be fair to say?
Well, yes and no. That is, I'm not really sure how deep a layer of rust this method will remove, because I have only used it on little bits and pieces of hardware that are not all that rusty.

This is a slower method than phosphoric acid though.

The only way I've used phosphoric acid is in Naval Jelly and a spray product made by Boeshield. I find Naval Jelly to be a bit of a pain because it has to be painted on, and think that the thickness actually restricts how deeply it can penetrate. The spray stuff is okay for very light rust, but it's quite expensive, (by volume, that is), and I don't like having the stuff in the air around me.

But I've ordered some straight 85% phosphoric acid from the Rembrandt people, (same place I got the asphaltum and am getting the rosin for the Japanning project), so I'll be able to make a better comparison once that stuff arrives.



I imagine frequent shakings might aid in removal, eh?
Sounds logical, but I tend to put it in the jar and forget about it for several days at a time, so I really can't say. :o



How strong a solution of citric acid did you make?
I don't know what it would be called in chemical terms. I mixed one cup of citric acid powder with two cups of white vinegar.


Here is another pic of the batch in the jar. The first was taken yesterday at about noon, and I just took this one at about 6 pm, so we're looking at 30 hours difference.

[Dan Moening]

Ahhh...that's what I would have expected the jar to look like after a bit of soaking...I see.

That's good news. I was excited to hear what your experience is with citric acid as I do want to get away from the phospheric stuff. I'll be interested to see what color change, if any, there is...



Suppose if I had read you first post I would have seen the proportions :rolleyes:

I've ordered some straight 85% phosphoric acid
Yowza!
I'm using a "rust remover" from Wink, in a brown bottle. I think I'd be hard pressed to say its more than 65% phospheric acid...and its caustic enough for me. :o But leaves everything an ugly battleship grey.

All in all, it sure is looking like a relaxed citric acid bath is a good solution.

{nice pun, eh? :D }

[Leif Hanson]

I've heard lemon juice works really well for getting tarnish off of small parts... supposedly better than vinegar on brass and the like. I don't know about rust, but can see it might be worth a try sometime. Just thought I'd mention it for more info...

Leif

[Boyd Gathwright]

Hi Tom,

.... Liked your report (POST) will be interested in your final results. I've got water marks on some machine surfaces and this MAY be a good approach to eliminating them. I'll keep an eye out for your future post.

.... Thanks for sharing ;).

Boyd

.

I have found that electrolysis is the best way to rid large chunks of metal -- plane bodies and froggies for example -- of rust.

But what about the little stuff? All those screws, knobs, and the like that hold the plane together?

Well, here's one solution I've come up with.

Supplies:

1 quart-sized glass jar with lid
1 cup powdered citric acid
2 cups white vinegar
some rusty bits and pieces of planes -- washed to remove grease and big chunks of junk

Dump the citric acid and vinegar into the jar, screw on lid, shake vigorously for a few seconds.

Add rusty stuff

Replace lid, but do not tighten all the way, as this will produce a bit of gas. (I have no idea if the gas would/could ever build up enough pressure to burst the jar, but I think it's better not to take chances, as this stuff would make a pretty gross mess to clean up.)

Set jar aside for several days.

[Jerry Palmer]

After using electrolysis on several saws as well as planes, I switched over, on the saws at least, to using cooking vinegar as a lubricant with 320 grit sandpaper instead of mineral spirits to remove rust after using a razor blade scraper to rid the blade of the loose stuff and other gunk. The vinegar cuts right through the rust and I can get a fairly rusty saw blade looking very good in about 20 minutes. I've been spraying with WD 40 or wiping down with a light oil to help nuetralize the acid action of the vinegar as it has a tendency to cause some discoloration of its own to the saw blade. Haven't had a really bad rusted plane to try this on since I started using it on the sawblades.


Adding the citric acid for greater acidity would probably speed up the process.

[Tom LaRussa]

I've got water marks on some machine surfaces and this MAY be a good approach to eliminating them. I'll keep an eye out for your future post.
Don't get your hopes up Boyd.

The only thing I have found that will remove water marks from machine surfaces is a power sander. :(

[Tom LaRussa]

After using electrolysis on several saws as well as planes, I switched over, on the saws at least, to using cooking vinegar as a lubricant with 320 grit sandpaper instead of mineral spirits to remove rust after using a razor blade scraper to rid the blade of the loose stuff and other gunk. The vinegar cuts right through the rust and I can get a fairly rusty saw blade looking very good in about 20 minutes. I've been spraying with WD 40 or wiping down with a light oil to help nuetralize the acid action of the vinegar as it has a tendency to cause some discoloration of its own to the saw blade. Haven't had a really bad rusted plane to try this on since I started using it on the sawblades.


Adding the citric acid for greater acidity would probably speed up the process.
Jerry,

I think your method makes much more sense (for saws at least) than using electrolysis, since it's difficult to find a bucket deep enough to hold most hand saw blades. I assume, though, that these are "user" saws and not fancy-shmancy "collectibles?"

For planes though I really like the electrolysis because I'm planning on getting into re-jappaning all my rehabs anyway and electrolysis takes off most of the old Japan from the rust-buckets I buy. :p ;)

As far as discoloration goes, it seems that every method leaves a little something behind. But they all seem to come off quickly and easily with either a wire brush in a buffer (or drill, or drill press) and/or one of those 3M type abrasive pads.

[Tom LaRussa]

I've heard lemon juice works really well for getting tarnish off of small parts... supposedly better than vinegar on brass and the like. I don't know about rust, but can see it might be worth a try sometime. Just thought I'd mention it for more info...

Leif
Leif,

You just jogged something in my memory with that comment. The cook's trick for keeping copper pots and pans nice and shiny is to scrub them with lemon juice and, I believe, table salt. Since brass is mostly copper, ( http://www.encyclopedia.com/html/b1/brass.asp ), it makes sense that the same thing would work for it as well.

:)

[Dave Anderson NH]

One warning if you clean saws with electrolysis. Electrolysis creates hydrogen and it gets into the steel of the saw and can cause a phenomena called hydrogen embrittlement. This is exactly what it sounds like, though it is reversible. As a gas, the hydrogen will slowly remove itself by gaseous diffusion. Think of it as evaporting though obviously gases don't evaporate. You get the idea though. Do NOT sharpen, strike, or use the saw for a few days after electroylsis so that the hydrogen can get out of the steel. If you do, you run the risk of breaking off teeth or cracking the blade. It's a small chance, but it can and does happen. The safer methods of sandpaper and a solvent, citric acid and a solvent, and the trusty old razor blade are preferable to electrolysis for saws.

[Jerry Palmer]

Yeah, the saws are for use and not some fancy smancy collectors. Another issue with saw blades is that speeding up the process of electrolysis by getting more current flow has a tendency to cause hydrogen hardening which means using up the time saved with the higher current in baking them or letting them sit in the sun to get them back to their original tension. The softer metal of the plane bodies aren't affected.

[Tom LaRussa]

Okay, so the stuff has had nearly two weeks to soak, so it should be all nice and shiny right?

Well, not really.

First off, I had to switch from vinegar-citric acid solution to a degreaser after the first five days, because the stuff was greasy enough so that the derusting fluid couldn't do its work.

That ate up about three days in the middle.

Today I finally took it out of the vinegar/acid solution and let it dry. And guess what? It almost instanly grows a brand new layer of rust! :eek:

BUT, this rust layer is purely surface, and comes off with just a touch of a power wire brush. (See the three screws in the lower right hand corner of the pic below.)

So, what's my verdict?

Well, it certainly is not a fast way to remove rust. On the other hand it takes almost no effort, save for literally a few seconds per piece with the power wire brush at the end of the whole thing.

All things considered I think it's quite preferable to derusting small parts purely by mechanical means.

[Greg Wandless]

Tom,

Next time after you rinse of the parts with water do another rinse with denatured alcohol to wash the water off then let them dry, you should get less new rust forming.

Greg

[Ken Garlock]

Hi Tom. Interesting experiment you have done. :)

The other day I was in a local farm supply store, while looking through their organic treatments I noticed that they had gallons of 15 or 18 percent vinegar. It is used as a weed killer. It seems that some high test vinegar would reduce your pickling time greatly. Normal cider vinegar is 5%.

Got a farm store around you :confused: