What did you do today?

[Tim Clarke]

I finished the case for my 18” Starrett Level. I’ve had it since the early 70’s. It was a gift from my friend Charlie. He told me it had belonged to his granddad. So it’s likely 100 years old or more. Hope it doesn’t turn out to be it’s coffin!

[PJK]

The timber you used appears to be oak, the tannic acid in the oak even if it is varnished, will corrode the level and the case.

[Cenedd]

Tim Clarke Beautiful work. I keep meaning to do something similar for mine. I hope PJK isn't right.

PJK What (commonly available) wood should be used instead?

[J Tiers]

The timber you used appears to be oak, the tannic acid in the oak even if it is varnished, will corrode the level and the case.

I think this is totally wrong.

Machinist boxes have been made of oak for over a hundred years, and if that were correct, the tools in them should be mere wisps of rust by now.

I have never had a tool corroded in an oak chest yet.

[Tungsten dipper]

I think this is totally wrong.

Machinist boxes have been made of oak for over a hundred years, and if that were correct, the tools in them should be mere wisps of rust by now.

I have never had a tool corroded in an oak chest yet.

They are lined in felt. Look up oak and tannic acid. I didn't believe this at first, but they use steel to make a stain for oak. It's called Ebonizing.
https://www.popularwoodworking.com/t...bonizing_wood/

[J Tiers]

They are lined in felt. Look up oak and tannic acid. I didn't believe this at first, but they use steel to make a stain for oak. It's called Ebonizing.
https://www.popularwoodworking.com/t...bonizing_wood/

if a layer of varnish (that seals the surface) makes no difference, then how do you expect a layer of very porous felt to make any difference at all? Anything and everything can go right through the felt, I have seen things corrode steel right through felt

Wood glues will corrode steel. years ago I had made a holder for a spare overarm (with vertical head). It was made with regular yellow wood glue, and allowed to dry for a week. It was felt covered. When the overarm was put on it, the surface was quickly rusted. I had to use hide glue to avoid the rusting, despite the glue being very thoroughly dry.

The hide glue was allowed to dry overnight, and never has caused a problem.

Felt is no barrier to rusting whatsoever.

Tannic acid will turn steel a black color, I have tried it (it has no anti-rust properties, though). Presumably that can be used to blacken the oak.

The amount in oak has never blackened anything of mine, neither the oak nor the steel. I do not think it is any sort of serious issue. Perhaps if water gets in and extracts tannins from the oak there could be an issue, but if there is water in the toolbox, I think you have problems which will totally obscure any issue with oak and tannins.😁😉

[Dave C]

I have a very old, Starrett mike that has replaceable anvils that make it different sizes. I am pretty sure that the wooden box that it came in is oak.

[Tim Clarke]

Ya, I have oak cases that I’ve built over the last 30 years, and have yet to see any problem. Also an oak Gerstner machinists chest. I would think that if oak was any problem whosoever that the gerstner factory would have been able to see it in the last 100 years or so.

[PStechPaul]

If the oak wood is kiln dried, and the box is not subject to water or high humidity, there may be no problem with tannin and corrosion. Here is some info (although more for building timbers and not cabinetry):

https://www.englishwoodlandstimber.c...cladding-beam/

https://www.woodworkingarchive.biz/s...nnic-acid.html (ebonizing)

https://www.fpl.fs.fed.us/documnts/p...zelinka003.pdf (effect of tannins on corrosion of steel)

[J Tiers]

Plus, what would that say about nails in oak? Never seen a problem with those.

[Tungsten dipper]

Plus, what would that say about nails in oak? Never seen a problem with those.

How long did you think about this? Good thinking...

[KIMFAB]

I got a 3D printer that I'm putting together.
https://www.youtube.com/watch?v=sf3Y_sdMJoU
Things are going slow because of my shakiness.

As far as the oak problem, maybe check with this outfit
https://gerstnerusa.com/shop/1805-chest/

[Baz]

Plus, what would that say about nails in oak? Never seen a problem with those.

Then you are very lucky and perhaps in a dry area. Old wrought iron nails were better but modern nails and damp will be a problem in only 20 years or so.

[J Tiers]

Then you are very lucky and perhaps in a dry area. Old wrought iron nails were better but modern nails and damp will be a problem in only 20 years or so.

Dry only if you consider 90 F and 90% to be dry.

Old nails probably had a higher copper content, which has made steels more resistant to rust.

Point being that oak has been in use for hundreds of years, including in shipbuilding, the material does not seem to rust everything away as has been suggested.

[Mike Burch]

"Nail sickness" in oak is a well-known phenomenon in wooden boat maintenance.