Aging oak and pine - tea + drain cleaner?

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SlowSteve

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Hello all.

I am "restoring" an old antique oak and pine sailors chest. The original finish on it was so awful that I have stripped it back to totally bare wood. I wouldn't normally do something like that, but the previous finish was horrifically applied by my grandfather and it was universally considered a mess.

Right now I have shiny glowing wood stripped back and then sanded to 180 grit. The wood looks brand new. SWMBO has ruled it needs to look "older but not rubbish" - as you can see I get very detailed instructions.

Looking on T'internet, there seem to be two routes open for aging the oak -

Drain cleaner - Sodium Hydroxide. This will yellow the wood and make it look like a finely cared for antique. Wax lovingly and ( in theory) it will look like it has been in a museum all of it's life.

Age with Black tea/ferric oxide+vinegar - this will add shades of grey into the mix and make it look like the chest has been exposed to the elements and sun-light all of it's life.

View from SWMBO is that the first route is too yellow and the second route is too grey. She wants "somewhere in the middle". Obviously.....

So - my question is, can I combine the two methods and hit the desired "A bit yellow and a bit grey" sort of shade?

Also - I know that the level of sanding is critical to changing the colour of wood. Do you think I have gone far enough at 180 grit, or would you suggest I step down to a 240 or a 320?

Thanks

Steve
 
SlowSteve":2bls0ybl said:
Looking on T'internet, there seem to be two routes open for aging the oak -
I think you want to do a little more research on this. What am I saying? I think you want to do a lot more research on this before you commit.

The Interwebs can be horribly bad when it comes to this sort of thing to begin with, and a lot of what you've read doesn't apply to oak, at least not in the same way.

First example is the sodium hydroxide. Strong alkalis don't make most woods go yellow, it makes many go darker, a few redder. Pronounced yellowing is generally seen on softwoods, not so much on oak! With oak you should get a very different result.

Now the black tea. It may be superfluous here because again you're working on oak, the tea is to introduce tannin (since most of these guides use pine, which has little or none) and of course oak already has tannin in it.

Lastly the iron dissolved in vinegar, how grey the wood goes comes down to the tannin level. If there's enough tannin present the wood won't go merely greyish, you'll get a charcoal grey or nearly black result.

SlowSteve":2bls0ybl said:
So - my question is, can I combine the two methods and hit the desired "A bit yellow and a bit grey" sort of shade?
Assuming the wood did go yellow initially then yes. I've done test boards (on pine) and got exactly this effect, a greyness with the initial yellow sort of peeking through from below.

Final issue is can you do it reliably? And the answer is no, afraid not. The problem with oak is the wood can be slightly different from board to board and with this project you're doing you don't have any offcuts you can test stuff out on so everything would be a gamble. Testing the bottom is an obvious thought, but it might not tell you anything for certain about how the sides and top will go because those are made from different pieces of wood.

SlowSteve":2bls0ybl said:
Also - I know that the level of sanding is critical to changing the colour of wood. Do you think I have gone far enough at 180 grit, or would you suggest I step down to a 240 or a 320?
I can't be 100% on this but I don't think the difference between sanding to 180 and 240 makes much difference to these sorts of effects, if I remember correctly it's more pronounced with dyes than with chemical treatments.

Beyond the initial treatments, on hardwoods I would generally sand higher than 180, with the final finish an important consideration. If you're varnishing any sanding scratches are lessened, if you're oiling they are highlighted.
 
Chemical staining has its place, but I doubt this is one of them. A water based aniline dye is the way to get the job done simply and efficiently, whilst still allowing for the precise colour control that your missus wants (multiple thinned coats, blending shades etc).

By the way, Oak is such an open grained timber that sanding the actual wood surface (as opposed to sanding an applied finish) past 180 gives rapidly diminishing returns. I know lots of craftsmen who would stop at 180 on bare Oak, although if you're knocking off the raised grain after water staining then there's maybe a case for 240. Faffing about with 320 and finer grits on a coarse grained bare wood like Oak or Ash is the type of silliness hobbyists indulge in, but you won't find professional woodworkers going that far.

Good luck.
 
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