Holly, in France wrote:
We
sandblast timber regularly, almost always oak though, which would be
harder than your scaffolding boards. It gives a rough, aged sort of
effect.

IMO it copmpletely ruins timber.


We replaced a big oak beam
in a house last week where the joists were still in good condition. The
joists are black since the room was originally used as a forge. The new
beam sticks out like a sore thumb! When the oak floor is down we will
sandblast the whole lot, including the underside of the floorboards.
There will still be a difference in colour but overall the effect will
be more uniform.

Why not blacken the replacement, instead of spoiling the lot?

One thought though, I wonder if this would be suitable
for furniture since the rough surface would be prone to collecting dust,
making it harder to clean.

Quite.