old tools

[Kurt Johnson]

I found some tools I forgot I had that had belonged to my wifes grewt uncle who was a tool and die maker for Eastman Kodak in Rochester, New York. He retired about 1960, so I’m guessing they’re about 100 years young. Most are Starrett and have a tiny amount of rust around knurled areas, etc. Is naval jelly okay to use to clean up these areas? I took a picture of a divider but I can’t get it to upload.!

 

Thanks, 

Kurt

[grsjax]

Best to use a brass brush and carefully remove as much rust as you can.  Then use very fine emery cloth and light oil to get the rest.  Naval jelly might be a but to harsh.

[Griphos]

If it's light rust, a little WD40 and some fine steel wool will do the trick.  If it's a bit deeper, then some sandpaper.  I've used flap sanding wheels in the drill for more stubborn rust/pitting.  WD40 is an oil, and seems to do a better job of assisting in rust removal than other products I've tried that are dedicated to the purpose.  Once clean, wipe with mineral spirits to get rid of the oil, and then use preservation wax or a spray protector like Boeshield T-9.   

 

I've cleaned up many a 19th c plane iron and early 20th c tools with these methods.

 

Old Starrett tools are top quality.  I've got a number of their old rules and other tools.  Congrats on the find.  

Edited March 2, 2019 by Griphos

[Kurt Johnson]

Thanks for the input. I had forgotten I had these tools and I want to put them back in use. So far I’ve used liquid wrench. The knurled areas are the worse and really not that bad. I’ll have to look into the Boeshield T-9. I love using tools like these. I really don’t mind the new digital stuff, but I really like the traditional tools used properly ( my father was a stickler about the proper use of a tool, and I bought it hook line and sinker. Happily! )

 

Kurt

 

 

 

 

[Kurt Johnson]

Okay, here is another related question. The two points on the compass are presently about 1/32” ( 0.6 mm )

different in length. I’m guessing from many years of wear, and from the way I would use it being right handed the shorted one would have pivoting a lot. I want this compass to use, not just look at. Does it make any sense to file down the longer one until they’ve equal? I realize this may be an incredibly dumb question.

[jud]

Makes no sense to me, as long as the compass will hold it's set, leave it alone would be my choice.

 

 

Edited March 1, 2019 by jud

[wefalck]

Never use sandpaper on tools, what idea ! For mild de-rusting I use used tea-leaves. The cheaper the tea the better, because you need the tannin, which is a complexing agent and will desolve the ferric oxihydroxides, vulgo 'rust'. Then you can use steel wool of various grades. For polishing one can also use a fine rubber-bonded abrasive block or similar wheels in the hand-held drill. Be cautious not to damage or change the shape machined surfaces that have function, such as sliding ways on tools.

 

One should be able to change the points on a compass. Sometimes they are sort of rivetted in, but one can pull them out using pliers. To function properly the points would need to be ground. The points on the marine-type of compasses can also be ground back into shape on a stone. The inner sides have to be flat and matching and the outer sides have be ground to a point.

 

 

[bruce d]

Surface rust can be dealt with by electrolysis. If you haven't tried this process before I am happy to tell you that is very easy and it works. Don't be too concerned about equipment, I have used an old phone charger for the last few years to clean up small items.

 

Here is a good starting point:

https://www.instructables.com/id/Electrolytic-Rust-Removal-aka-Magic/

 

HTH

Bruce

[Kurt Johnson]

I had said compass, I had meant to say dividers. 

[Griphos]

5 hours ago, wefalck said:

Never use sandpaper on tools, what idea ! For mild de-rusting I use used tea-leaves. The cheaper the tea the better, because you need the tannin, which is a complexing agent and will desolve the ferric oxihydroxides, vulgo 'rust'. Then you can use steel wool of various grades. For polishing one can also use a fine rubber-bonded abrasive block or similar wheels in the hand-held drill. Be cautious not to damage or change the shape machined surfaces that have function, such as sliding ways on tools.

 

One should be able to change the points on a compass. Sometimes they are sort of rivetted in, but one can pull them out using pliers. To function properly the points would need to be ground. The points on the marine-type of compasses can also be ground back into shape on a stone. The inner sides have to be flat and matching and the outer sides have be ground to a point.

Of course it is perfectly desirable to use sandpaper on tools. I’m not talking about 100 grit red oxide. I use 400 grit wet/dry or finer such as auto shops use. Sandpaper is just an abrasive grit on a flat medium. It is no different from steel wool or, indeed, the polishing abrasive block you mention. All of them are simply various grades of abrasive grit on various media. You grind your tool edges, right?  Same principle. Sharpening stones often use the very same abrasive particles as sandpaper. 

 

For sharpening my edge tools, I have a piece of dead flat 3/8” plate glass about 10” by 24”.  I’ve glued sheets of sandpaper to it ranging from 320 to 2000 grit. A few strokes on each grit sharpens and eventually polishes and hones the edge to a mirror finish and a sharpness that easily shaves the hair off my arm. Decades ago this method became popular on an old tools list and was nicknamed the “Scary Sharp” method. 

 

Polishing is no different.  It is simply the process of replacing fine scratches/abrasions with finer scratches/abrasions. It goes faster if smaller increments of intermediary grit is used.  So, removing surface rust from metal is easily done with abrasion, rather than chemical process. And if the right grit is used, both the rust is removed and the metal is polished. 

 

I may not have the experience many here have with modeling, but I have over four decades of experience refurbishing and using antique and modern tools in making furniture and fine cabinetry. Old tools are something I know a great deal about. 

 

As for the difference in the length of the compass legs, a much bigger difference than 1/32” will not affect use at all. As already stated, if the locking mechanism is solid and the points don’t move, then they will work perfectly. You will move your hand while using them, changing the angle of contact, so perfectly equal length is moot. When using them to scribe (rather than scribing circles), the reference surfaces will not usually be at the same height anyway. 

Edited March 2, 2019 by Griphos

[wefalck]

When using 'sandpaper' you will probably change the shape of the part. So you really have to know what you are doing. The other 'abrasives' metioned are more compliant and are less likely to change the contour of the parts. Of course, it depends also on whether you work on old agricultural tools or on fine measuring tools. I gather we were talking about the latter.

 

When you know what you are doing, you can regrind flat surfaces, such as the sole of planes, on a piece of fine wet-and-dry attached to a perfectly flat surface, e.g. a glass plate. I indeed used this technique in reconditioning machine tools.

 

For measuring and machine tools it is also important to remove all abrasives residues carefully.

[Griphos]

We are indeed talking about the latter.  And whether or not you change the shape of the part is dependent on the grit of the abrasive, the stability of its backing (including whatever the sandpaper is attached to or wrapped around) and your technique.  Again, I'm not talking about 100 grit garnet sandpaper that you might use on wood, or even aluminum oxide, although that's a perfectly good abrasive in the finer grits.  I'm talking about silicon carbide, at 400 grit and finer.  You can change the shape of the part - dull the edge or round off a corner - with pretty much any abrasive.  When using any abrasive (including polishing compounds or even steel wool) on any part, you need to know what you are doing.  Other abrasives are not more "compliant" (whatever that means).  Abrasive is abrasive.  It has a grit and a medium and some kind of backing.  A rubber abrasive block or wheel will just as readily alter the shape of a part if used badly.  

 

You said "Never use sandpaper on tools!"  That's simply not the case, as the vast majority of people who work with tools can attest.  

Edited March 2, 2019 by Griphos

[Bob Cleek]

5 minutes ago, Griphos said:

You said "Never use sandpaper on tools!"  That's simply a deeply erroneous and uninformed remark.  

Now, now... let's not get pissy. "Different ships, different long splices," as the saying goes.

 

That said, if I ever saw anybody taking sandpaper to my fine drawing instruments, I'd whack 'em upside the head.

[Griphos]

I changed that line instantly, since I saw that it would read as unfriendly.  You must have seen it in the minute in which it was live.

 

I think we may be forgetting that the OP asked about cleaning rust from knurled areas in particular of older and not maintained tools.  In my advice, I suggested he start with steel wool.  If the rust is deeper than light surface rust, then he may indeed have to be more aggressive.  I would say that 400 grit sandpaper wrapped around a slender edge, like a putty knife, perhaps, or a hand made hardwood wedge of acute angle, would be better than using a file to get into the knurled area.  I don't think anyone was suggesting sandpaper as some kind of maintenance regime on fine drawing instruments.  Knurled knobs are quite tricky to remove rust from. 

 

You can soak the knob in white vinegar, but it will likely etch the metal as it lifts the rust.  It's an acid.   

Edited March 2, 2019 by Griphos

[wefalck]

For the knurls, I would use tea-leaves and then a wire-wheel. This is pretty much what I used in 25 years of restoring watchmaking machinery.

[Bob Cleek]

6 hours ago, wefalck said:

For the knurls, I would use tea-leaves and then a wire-wheel. This is pretty much what I used in 25 years of restoring watchmaking machinery.

I've never before heard of using tea leaves for anything other than brewing tea and telling fortunes. How is it done? Is the piece soaked in tea? Are the leave applied wet as a paste and left to sit. Are they rubbed on dry? Can you explain the technique?

[wefalck]

As I said in an earlier post, black tea, particularly the cheaper and more fermented varities, contains a lot of organic acids, the stuff that makes it taste bitter and sour, and look brown. The longer you let the leaves soak in hot water the more you get this stuff out of the leaves. Therefore, also using the leaves from your earlier cup'o is fine. These organic acids dissolve the the rust, bringing the iron into solution and keeping it there by forming stable chemical complexes. These acids are too weak to attack metallic iron.

 

In practice, you have to first brush off any loose rust and degrease the parts in e.g. acetone or cleaner for motorcycle chains or another degreaser. Rust soaked with oil is not being attacked by the organic acids. This is particularly important, when you used creeping oils, such as WD40, to make parts move for dissambly.

 

You then take a bowl or other vessel that allows the part to be completely immersed. It may be wise to use a disposable vessel as the deep black iron-organic compounds are very staining and stick to any rough surfaces. Also wear gloves and protect your clothing - it is almost impossible to get these stains out of clothing.

 

This vessel you fill with a thick soup of tea-leaves and you completely immerse the part in it. Any surface that is exposed to air may begin to rust, so complete immersion is important. Leave for 24h and check the progress by taking the part out and rinsing it. You can basically leave it in as long as you like. Move it from time to time to bring the surface into contact with fresh solution.

 

Once you are satisfied with the progress take the part out and brush it under runnging water e.g. with an old tooth brush. You may need to do this also in between for knurled parts to remove the conversion products. When clean dry the part immediately and very thoroughly. Compressed air is a good idea, if you have it. Otherwise, you can immerse intricate parts, such as knurls, into acetone to be sure that the water is displaced from all crevices.

 

For simple, smooth parts you may be done now, but for intricate parts, where the conversion products have settled in crevices, you may need to apply a wire-wheel.

 

I have used this technique for decades on my antique machinery, where it is important that you don't change the geometry of load-bearing surfaces.

 

Just one word of caution: some people also recommend using Coca Cola for that purpose. This drink contains inter alia organic acids and phosphoric acid. While the organic acids dissolve the rust, the phosphoric acid will form solid iron-phosphates (a mineral called Vivianite) that are quite insoluble, once precipated on surfaces. You have to constantly remove and clean the part to prevent these phospates from precipating in crevices. They are virtually impossible to remove from there. This property is used in so-called 'rust converters', which are basically phosphoric acid solutions,  in the automotive sector, where you want to convert the rust in situ into something that replaces the metal and sticks to remaining metal. These Vivianites are very hard, harder than the iron/steel and are difficult to grind down - not a good thing to have on surfaces that have to geometrically exact for mechanical reasons.

[thibaultron]

Just to put my 2 cents in, a few things I learned about derusting tools while rebuilding a milling machine.

 

Take your average new steel bar. The surface you see is not the steel, it is an oxidized clear surface that is preventing further rust! If you dip the end in a rust remover, pull it out and clean the chemical out, the entire surface will start to aquire a light rust coating. You have to polish it to restore the very fine surface oxide surface. I found this out through reading after trying both electrolysis, and rust removers on the milling machine parts, only to have the parts start to get this light rust as soon as I pulled the parts out of the electrolysis tank, or removed the chemical cleaners.

The rust converters, do leave an un-removable coating, as such, I'd worry about using them on critical surfaces, like slides, measuring surfaces, like the tips of micrometers, etc.

 

My final solution was electrolysis followed by a lot to hand polishing with steel wool for the sliding surfaces, and fine sanding on the cosmetic ones. Or wire brushing for lightly rusted areas. I did not end up with a new looking machine, but everything worked as it should, and it cut accurately.

 

For the electrolysis tank I used a large plastic storage tub, the kind you can buy at any major store in the US. The supply was a battery charger I built for the batteries (lead acid seal ones used in emergency lights, motorized child cars, etc.). It had an Amp meter and as the part became less rusty, the current would drop. Any low voltage DC supply would work. Be sure to kill the power before you stick your hand in the water! It has been 20 years, so my memory is a bit vague, but I think I used Washing Soda (not baking soda) in the water. This is available in the laundry detergent aisle, here in the US.

 

In the end, if I had simply gone over the sliding surfaces with some fine steel wool, and wire brushed the rest, I would have been better off.

 

So for just fin rust, a wire brush, or steel wool, with maybe dental picks for the bottom of the knurls.

[wefalck]

Fresh rust is FeOOH (ferric oxihydrate), which is brownish red and fluffy. This is easy to remove with a wire brush. However, I often had to deal with pitting rust, where the FeOOH was converted, due to subsequent dry storage over decades, into Fe3O4 by dewatering the FeOOH. Fe3O4 is of a dark brownish, sometimes metallic colour and hard. This is very difficult to remove with a wire brush, but cleans up nicely with the tea-leave method. The pits, of course, remain.  

[Bob Cleek]

Thanks, weflak! I'll have to add that to my bag of rust tricks. Heretofore, I've been pretty much a wire wheel and steel wood kind of guy.

 

[Keith Black]

 Knowing a little of what I speak, once metal has pitted, the only way to remove pitting is to sand to a level surface with whatever grit is required to get the job done. This WILL change the shape of the metal. My thought is to clean the surface by whatever means works, lightly oil, and leave/live with the pitting. 

 I have antique firearms (small caliber) that have pitting, do I wish it wasn't there, of course but I'm not about to try to sand them out. I look at pitting as being a part of the history of an object. If it's a body panel or some such, that's why God made Bondo. 

[Kurt Johnson]

Well in the end it was no big deal, just a brass brush and some T9. It’s almost good enough for government work. I was going to try the tea, but decided not to. Thanks for the input, I learned some things and that’s always to the good.  Thanks guys.

 

Kurt

 

 

 

 

 

 

 

[Griphos]

The nice thing about those old calipers is that the parts all come apart and can be reconditioned individually.  Allows you to get at all the crevices and joints.  

 

Enjoy.  

[Thistle17]

There is an excellent reference in the magazine "Fine Woodworking", Tools & Shops", Winter 2019 on pages 80-86. It speaks to products and techniques for rust removal, prevention and maintenance. If you can't obtain it in the library go to Taunton Press, Fine Woodworking.com.

Joe