Sciencemadness Discussion Board

Preserving steel tools

math - 26-6-2008 at 07:37

hello all,

due to high humidity my iron/steel tools,
as screwdrivers, pliers etc keep rusting.

Some time ago I bought some special
clothes which have some substance in them,
when rubbed on metal tools they preserve
them shiny and also WITHOUT an oily finish,
which of course is undesiderable on something
you have to grip securely in your hands.

Which chemical could possibly be and are there
similar tricks to preserve steel things without getting
them oiled up?


Thank you in advance

JohnWW - 26-6-2008 at 11:20

You would have to either buy tools made of stainless/rustless tool steels (which besides C and Ni and Cr would probably also contain small amounts of Co, V, Mn, Mo, W, Nb, Ta, Ti, but which are corrosion-proof only in an oxidizing environment in which the oxide film is not continually removed), or plate with a hard layer of Ti (Ti-coated drill bits are available), or passivate non-stainless steels by treatment with HNO3 which results in an impervious layer of Fe3O4, or galvanize the tools by electroplating with Zn or dipping in molten Zn or a Zn-Al mixture (galvalume, about 50:50). The latter two possibilities can only be satisfactory if the protective layer is not liable to wear off when the tool is used, so they would not be suitable for metal-working or stone-working tools. Otherwise, you would just have to keep them coated with a liquid which excludes water and air between use, i.e. lube oil, or petroleum grease, or a silicone or fluorocarbon substitute.

With regard to tool steels, the thread on Sword Forging in the Technochemistry section is relevant here.

[Edited on 27-6-08 by JohnWW]

DJF90 - 26-6-2008 at 14:42

I've heard that keeping mothballs in your toolbox prevents them from rusting because of the naphalene (is that the right stuff I'm thinking of?) content. I'm not sure if this would impart an oily coating on your tools but maybe a little research into this suggestion will lead results.

not_important - 26-6-2008 at 17:34

Antirust formulations fall into two general class, so far as I know.

A) waterbased ones that contain soluble silicates and/or phosphates, which form protective films on the ferrous surface. Some contained small amounts of dichromates, less likely nowadays, or other oxidising agents to form a passive surface. Others contain amines or amine derivatives of fairly low volatility, these mop up acids that promote corrosion.. A few also had water dispersible polymers that form protective layers; these may be amine-containing too.

B) Amines, hydroxylamines, or hydrazines, with several substitutes in the C1 to C6 range. They can be in a volatile base, in an oil or wax carrier, or in paper intended to be wrapped around unused ferrous objects to protect them. The substitutes are chosen to give a fairly low vapour pressure, but still high enough that some amount of the compound(s) is present on every surface of the ferrous object.

MagicJigPipe - 26-6-2008 at 20:00

The cloth you are thinking of contained some sort of "silicone" type oil. I used to have one. It was for protecting firearms from corrosion.

Panache - 27-6-2008 at 07:36

sodium benzoate is a useful corrosion inhibitor if your tools are used around food machinery.

Mr. Wizard - 27-6-2008 at 07:38

I'm going to guess or speculate you have a jug of Muriatic Acid, Hydrochloric Acid or some type of acid chloride stored in the same area as your rusting tools. I stored an unopened jug of pool acid in a fairly well ventilated garage for a year, and every piece of steel in the whole garage had a patina of rust on it. When I got rid of the pool acid (Hydrochloric Acid), all the problems stopped. The bottle never leaked and was never opened. A nearby town has a chemical plant that used to vent Chlorine into the air at night when nobody could see it. It was all a big mystery with everybody in charge pledging to find the source of this mystery cloud that would rust galvanized fencing and rot copper radiators on cars, and make their chrome bumpers rust. The venting has stopped, the stench is gone and the fences don't rust anymore.

In short: CHLORIDES = RUST, in fact even more generalized HALIDES = RUST. Look for the source and put it away from your clean metal surfaces. The oil will help but it's more treating the symptom than a cure.

My two cents worth.

evil_lurker - 27-6-2008 at 09:27

Boeing makes some antirust stuff that supposedly puts something on your tools. They sell it at Sears.

Krytox

F2Chemist - 30-6-2008 at 14:52

If you can find low molecular weight Krytox (a DuPont product), apply a very thin film to your tools by wiping them with a cloth containing it. Krytox is a great lubricant that is non-reactive and virtually insoluble to most organic solvents. The only downside is that it is extremely expensive, although a little goes a very long way.

mycotheologist - 21-4-2012 at 15:14

Quote: Originally posted by JohnWW  
or passivate non-stainless steels by treatment with HNO3 which results in an impervious layer of Fe3O4


How does the Fe3O4 layer hold up to abrasion? I live by the sea so everything rusts heavily around here, a few days ago I had to get my lock fixed and the locksmith recommended putting WD-40 on all the locks. The most vulnerable items in my lab seem to be stands and accessories. I'm considering of oxidising them with HNO3. Except for the threaded/screw in part, I'd say oil would be a better option for that screwing in and out would probably cause abrasion of the Fe3O4 layer.

bahamuth - 21-4-2012 at 18:06

Keeping a cloth pouch filled with camphor among the tools supposedly does wonders due to sublimation of the camphor covering your tools with a very thin layer of it, and in my experience camphor is not slippery at all, perhaps opposite..