surface rust on lathe ways

[Simon CollierParticipant @simoncollier74340]

I have just seen a lathe from a deceased estate in as new condition, with immaculate paint, etc., It has a custom make vinyl cover, and the 4 jaw was still unused in its original bag. It is a Hercus, probably 1960's. However, unaccountably, there was surface rust on the ways. At some point, it must have been uncovered for a significant period, I suspect after sudden illness or accident, as the gentleman took great care of his tools. The question is, how much of a problem is this? Will it come off with a rub over with oiled 1000 grit wet and dry or what? Otherwise this is one of those dream finds. Think Super 7, only bigger, 4-1/2 c.h. I think.

Simon

[Simon CollierParticipant @simoncollier74340]

[Simon CollierParticipant @simoncollier74340]

This shows it.

[Neil LickfoldParticipant @neillickfold44316]

The picture is not really good enough to make a call on that. I find that if the fine grey scotch brite or at most the redy brown scotch brite does not clean it up, and it is all pitted, who knows how much damage there is. I did a fixup on a Tesa comparator that has surface rust on it. The owner thought it needed to be reground and lapped again. From the tests I did, the main table was still very good. So we got lucky. But on a toolmakers vice that went rusty in my shed from a roof leak, it pitted so bad, that it took 1mm to clean up both sides, .5mm on each side that was rusted. That really ticked me off that was for sure.

Neil

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Simon, I would have thought that a rub down with a wire brush, followed by cleaning with penetrating fluid and rag and then oiling would be OK. I would be reluctant to use any abrasive on it myself.

Regards Nick.

[LambtonParticipant @lambton]

Simon,

Start with oil and fine wire wool. This will remove surface rust without removing metal. I would then leave any pitting alone as it will help to retain oil.

Eric

[Alex CollinsParticipant @alexcollins55045]

You can clean the surface rust off with Scotch Brite. I'd not use anything more aggressive than that. Certainly not wet n dry …..

​Give the bed a good coat of slideway oil afterwards.

[Simon CollierParticipant @simoncollier74340]

Thanks for the replies. It is still in the late owner's workshop, not mine. All I could do during a brief viewing was find some WD40 and spray it all, not ideal but better than nothing for now.

[BazyleParticipant @bazyle]

If you ran the saddle up and down to try it out you will need to take it off and clean underneath.

Vinyl covers are a bad thing, even though they were sold by lathe manufacturers. They were intended as dust covers in a heated industrial workshop. Use a cotton sheet, not a man made fibre one.

[Neil WyattModerator @neilwyatt]

If it's just a dusting of rust, I would start with a phosphate based proprietary rust remover like jenolite.

Although this will convert the rust to dark staining, the end result will probably be dimensionally indistinguishable from the original.

Neil

[Ian S CParticipant @iansc]

The main thing to over come a light film of rust is use, same goes for all tools. I think you'll like it, Aussie Southbend.

Ian S C

[KWILParticipant @kwil]

Neil,

Your chemistry may be better than mine, but swapping ferrous oxide for ferrous phosphate only slows the process. The "black stain" you refer to is almost as crumbly as rust and is best removed so that you have clean metal on which to run, suitably covered with slideway oil.

Having used "Jenolite" type products, which are a weakened form of phosphoric acid, I have always found the it fails to penetrate fully to the bottom of each "pit" and it must be abraded by by some means such as a wire brush to remove all the black phosphate. Only if very lightly filmed with rust, ie very small pits, will the process remove the rust.

[egaParticipant @ega]

Neil Wyatt:

Can you still buy Jenolite rust remover? I haven't seen it on sale for many years.

I trust you are fully restored to health.

[Neil WyattModerator @neilwyatt]

Hence my comment 'If it's just a dusting of rust'. I've never found a thin phosphate layer crumbly and it has the dual advantages of resistance to further rust and holding oil well. Downside is the cosmetic effect.

One item I have that has been treated like this is my CI faceplate, which suddenly acquired a streak of rust for no apparent reason. The dark stain it now has doesn't feel in any way different from the rest of the faceplate. I suppose I could take a skim across the faceplate, but I'm not hung up on the appearance.

The main thing here is that rust takes up vastly more space than the iron/steel it replaces (ratio of 3:1 to 7:1), so what looks bad may actually not have a significant effect.

Neil

[JAParticipant @ja]

Oil and then use. After that review the situation. I don't think it will be that bad.

Just don't charge in and use anything aggressive like abrasives or phosphoric acid (Jenolite).

JA

[KWILParticipant @kwil]

ega, Jenolite is still advertised on the Web, Am**** etc

[Nick_GParticipant @nick_g]

Posted by ega on 14/02/2016 11:37:11:

Neil Wyatt:

Can you still buy Jenolite rust remover? I haven't seen it on sale for many years.

I trust you are fully restored to health.

.

Hammerite sell a product called 'Krust' which they describe as 'eating rust'. I presume by this that it breaks it down. I am however far from understanding the chemical process and it's implications and would be reluctant to use it on a lathe bed without additional advice.

IF it were me and so long as it was only a dusting of rust I would slacken the gibs on the saddle slightly and go through the pretend motions of using it. I would use a very light oil e.g. one intended for air tools. Wiping away often and replacing with fresh. Gradually I would nip up the gibs again and increase the viscosity of the oil with proper slideway oil.

Nick

[Ady1Participant @ady1]

Take the heavier rust off with oil and a sacrificial pan scourer(the foam type with the rough green top)

Leave the harder to remove rust, put oil on the ways and use the lathe regularly

The rust will clean off naturally AND any imperfections in the bed/ways will be highlighted

[JAParticipant @ja]

Rust (Iron Oxide) and Phosphoric Acid produces Iron Phosphate and water. Iron Phosphate is hard and insoluble in water. However it is porous and works as a protective coating by its ability to absorb oil. Usually it is painted over and the porosity is filled with paint instead of oil. How effective it is at withstanding normal wear and tear in its naked form I don't know but I guess that it is not as good as a heat blued finish which holds oil in a similar manner.

Iron Phosphate is so good at holding oil that steel tube prior to being drawn is frequently phosphated so that oil is drawn through the die with the tube.

JA

[MWParticipant @mw27036]

You want a good rotary tool to make the clean up a little quicker for cleaning large areas.

Michael W

[Nick_GParticipant @nick_g]

Posted by Michael Walters on 14/02/2016 12:56:07:

You want a good rotary tool to make the clean up a little quicker for cleaning large areas.

Michael W

.

Can you expand on that.

I read that as being anything between a dentists drill, fly cutter, angle grinder or a 1000mm face mill.

Nick

[AjohnwParticipant @ajohnw51620]

I wouldn't use jenolite on it. It's good at generating a key for subsequent painting. All rust removers seem to be like that. Cement cleaner has a similar effect but rust comes rapidly after it's removed and the metal finishes up grey. Some people have used the reverse electrolysis method on lathe beds. The fluid is in some rag and a steel plate placed over it. This suites some beds more than others.

I would be inclined to take a tip from used machine tool sellers who often have to cope with rust. Paraffin is essential. The reason being that at some point it will have had oil on it and there will still be a bit or some gum there. It also prevents what ever else is used from clogging. For a fist try I would use one of those usually green kitchen scouring cloths, about 6" square and sometimes stuck on one side of a piece of sponge. It's a sort of weak scotch cloth. Wire wool would be ok too. The chances of removing any significant cast iron with either is remote. Rust comes of much more easily but may leave a bit of pitting. Usually using either of these just leaves a patina. Some people foolishly might use a diamond hone. That will remove cast iron so can be useful for sorting out machine slides. Some might use a polishing mop, that will too. A brass brush may be useful too but sometimes these are plated steel which will be a bit more vigorous. Very unlikely to do any harm though providing it's just used to remove the rust.

The dealer would get right down to it and use something like grade 200 to 280 emery cloth or wet and dry. Sounds drastic but they take care – they just remove the rust and don't try to get a high polish.

Personally if I ever found a southbend clone like that which seemed to be more or less unused I would have it like a shot.

John

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[John McNamaraParticipant @johnmcnamara74883]

Re Cleaning

I just purchased some Browne and Sharp straight edges, one was a bit neglected and there was rust on the nicely scraped face, not really a worry as I planned to re scrape it against a known surface plate anyway if need be but it had to be removed pronto.

Before I go on those of delicate disposition may pass over the following notes.

My normal process for removing rust is to start with strong detergent water and sponges rubbing vigorously, at this point no abrasives have been used. This removes the rust mixed with oil and any other loose matter.

Then I dry the object to see what is left.

In the case of the rusty straight edge it removed maybe 50% of the problem.

for the next step the remaining parts of that needed more vigorous treatment were rubbed over with a sponge and a little Ajax powder (No Scotch Bright which contains very sharp abrasive particles, try a piece on a sheet of glass it will be scratched and ruined) I use a sponge because it does not allow the Ajax to bite in. yes it is abrasive also but a lot milder than Scotch bright.

This left maybe 80 % of the face clean.

There were some stubborn spots left. these were treated individually with Ajax and the fingers gently rubbing the spot. and in a couple of cases fine steel wool. Not the heavy industrial stuff.

The result is the straight edge is now clean of rust and you can still see the original scraping marks. and the rusting has been stopped. I have used this process a number of times on second hand tools and it has worked well.

When finished it is important the part is washed with clean water and dried with a cloth and oiled. Don't wait for it to dry or you may get a brown stain. and use light machine oil not CRC RP7 or any of the other similar canned products they do not last for more than a few days and often leave a stain on metal.

The Hercus is a great machine built by a great Australian company I still have the sales brochure for one, At the time it was beyond my means. The rust visible in the photo does not look that bad, fingers crossed. PM me if you would like a photocopy.

It is amazing to see the original paint in pristine condition. that will have to be masked off and covered together with any exposed metal before any cleaning process is contemplated.

Regards
John

[MWParticipant @mw27036]

Posted by Nick_G on 14/02/2016 13:04:02:

Posted by Michael Walters on 14/02/2016 12:56:07:

You want a good rotary tool to make the clean up a little quicker for cleaning large areas.

Michael W

.

Can you expand on that.

I read that as being anything between a dentists drill, fly cutter, angle grinder or a 1000mm face mill.

Nick

Lol, well i guess i didnt mean like a Dividing head or a pin vice but more on the spectrum of angle grinder with appropriately mild abrasive or polishing disc attatched. I wouldnt want to stand there for hours meticulously polishing every spot by hand but thats just me 😛

Michael W

[AjohnwParticipant @ajohnw51620]

Those kitchen scourers I mentioned are way way short of scotch cloth John. I spent a lot of time hanging around a used machine tool dealers. What they do will work out but it need some care – they don't rub hard with the emery at all. It's more like wiping with a scrubbing pretty action. I pulled a face when I saw them doing it and they showed me that there wasn't any dimensional change.

There used to be a gent who lived in Sutton Coldfield that cleaned up rusty machines. Really rusty ones at times. He wouldn't tell anyone how he did it. Sad as he probably isn't around any more. One thing is certain he rubbed something or other on the rust with his finger and the stuff flaked off. Very slow, maybe months and he seem to work along a lathe bed – or appeared to. My guess is that it was something that caused a electrolysis to occur at the boundaries. No idea at all what it was but he seemed to keep it in the kitchen so people tried all sorts of things that are usually kept in there.

Where I have used water as one of the things to remove rust and any oil I spray it with a water displacer as soon as possible. WD40 or duck oil etc.

John

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Edited By Ajohnw on 14/02/2016 14:55:15

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