In the past this has been discussed at length on this forum with references to a number of scholarly papers. In other words this has been extensively researched by museums, the timber industry and others.

In essence all timber is corrosive to some metals including mild steel. The corrosion is due to acetic acid.

A very late at night post which I generally avoid,

JA

Edited By JA on 03/04/2023 23:10:00

Tannic acid in oak hence the "tannins" and why oak bark is used in the leather tanning process.

Drying the wood will reduce the acid contents effect, anyone who has worked "green oak" will know it turns your tools black very quickly and will also as mark as quickly if left in contact with iron or steel for a shot time. Takes a lot longer to see that on kiln dried material but get it moist again and the acid will become more active. link

Edited By JasonB on 04/04/2023 07:25:47

As JasonB says, kiln dried oak later becomes damper, the acid is reactivated. Also, comments about the sapwood making steel tools black and the youngest wood, the bark, being used for tanning. I think that if heartwood, which is many previous years growth, already drying out in the tree is rather more benign, it suggests that the acidic effect slowly degenerates with age. Only the bark and sapwood of any tree species is the living part and the heart wood is dead.

Any potential problem could be overcome by putting VPI paper in an oak box/toolmakers cabinet, to prevent rust forming.

John

Dare I suggest Model Engineers are often naive about materials, tending to believe family names refer to one thing, or are all much the same. No so, there are thousands of different 'steels', over a hundred 'Brasses', and dozens of 'Bronzes'.

In this case there's a isn't a single wood called 'Oak'. Instead there are over 500 members of the oak family, plus a number of woods called 'oak', that aren't Oak at all. As plants have adapted over millions of years to their environment, it should be no surprise that English Oak is not identical to Asiatic or American Oak. Thus some oak woods are far less corrosive than others. The simple answer is making a tool cabinet out of the wrong type of oak will lead to tears.

Tool storage is a broad subject. Steel toolboxes are strong but – unless air-tight or lined – they don't protect well against corrosion because steel is a poor insulator, which encourages condensation. Wood is a good insulator, but it decays and is likely to emit corrosive chemicals. Also risky to use treated wood, because the nasty chemicals used to slow down decay can be corrosive. How fast wood decays depends on the circumstances – wood is vulnerable to damp, insects, fungi and bacteria. How it was seasoned matters too – slow dried wood is more stable in the long term than fast kiln-dried wood.

Bottom line: if a box is made to protect steel instruments, the builder needs to select an appropriate material, not just guess! Or combine materials to improve performance. For example, I have steel drawer tool-boxes in my rather inhospitable main workshop, but these are lined to improve insulation, and delicate tools are boxed in cardboard plastic containers as well, often with vapour paper, or lightly oiled. Inside the house, I have another workroom mainly for electronics. It's much more civilised, no oil at all, and a nice oak tool cabinet would sit nicely in it. Actually, most of my indoor storage is steel framed plastic drawers, with bigger tools hung on the wall. The room provides the necessary protection.

My feeling is that oak cabinets are most suitable for tidy indoor set-ups, fine work like clock-making, not my crude brand of shed-style metal hacking!

Dave

Yes and it may be so for the acid they mention but the usual one in oak is Tannic acid, if you read my link you will see it's full name is Quertannic acid and we all know the latin for Oak is Quercus. Here is another link saying it's effects can be reduced by drying, 

Edited By JasonB on 04/04/2023 12:16:16

Out of interest I have made boxes from all sorts of wood including oak but because of the story of corrosion I always seal all of my boxes with cellulose sanding sealer and let it go off for week or two or till the smell disappears which proves it is properly dry and then sometimes glue in felt liners or inserts using UHU general adhesive which can attack steels unless left to dry properly again till the smell has gone. I have got some really old beech at the moment (ex school) which is about 60 years old so that should keep me box making for a while. Just another point PVA based glues are corrosive for quite a while after they have hardened.

There certainly is a lot of "traditional" wisdom (aka folklore) that the tannin in oak can cause corrosion of steel tools, but that the tendency can be neutralised by "fuming" in an ammonia rich atmosphere. There was plenty of oak, but never mahogany, tool chests in the cold and damp satanic mills of Clydeside, usually where the more sophisticated work was done. Quality tool chests might well have been "fumed" but are the cheap imports? I have seen a mahogany chest on sale at an antique fair – it was alleged to have been the property of a clock maker. The same stall was also offering a wrongly assembled Pultra. When I asked (tongue in cheek) what it was, I was told £350, which probably speaks to the knowledge of the stall-holder.

Dick

I made a 'box' for taps by milling grooves in mahogany blocks about 20+ years ago. Not rusted yet…

YMMV!

Neil

I believe it was my comment that sparked this debate so I'll give my two pence.

I have a couple of boxes I made from kiln dried English oak which I finished with danish oil and wax, they are lined with felt. I have never had any problems. But then I also keep my tools well oiled and sometimes in plastic bags within the box. I had heard the rusting rumours prior to making the boxes but figured if it was good enough for the countless manufacturers of engineers tool chests it would be good enough for me too.

Far far worse is tools wrapped in paper or stored in cardboard boxes, I have seen hundreds of tools ruined this way. Paper holds moisture. Don't do it.

The majority of my best tools are oiled and stored in thick plastic ziplock bags, I believe this negates the choice of container somewhat.

I used to work for an oil distribution company, delivering the small orders that their big supplier didn't want, their minimum load being 6000 gals. So my employer sold paraffin burning stoves 'alongside' the fuel. They did an awful lot of home heat oil, doled out from a small metering tanker of about 600gals., meter producing an Invoice for the customer to pay. Think price all those decades ago was 1s and1 1/4d a gallon! Company purchased stoves from manufacturer who packaged them in cardboard boxes. They were stored in a locked brick store on top of a canal embankment very close to the sea. It turned out that cardboard had been made from acidic Thames water and in that damp old store, all the chromed parts went rusty.

John

Across all the comments the common thread would appear to be 'dampness' – rather than directly the wood itself. (of course some of the constituents are complicit but mostly in exacerbating the effect of dampness.)

Generations of woodworkers using metal tools with constant exposure to wood could reasonably argue that this is hardly a significant issue.

Merely an observation.

Regards.

Frank C.