I use almost exclusively reclaimed timber and my preparation is thus:
Using a claw hammer I remove all the nails I can see (and if they've been holding battens then there will be hundreds!).
Then I check with a stud and metal finder and mine, even though cheap, is quite capable of finding any bits of rusty nail left behind.
Occasionally I have to dig around with an old screwdriver to expose them before pulling out with side cutters.
When satisfied all the metal has been gone I go over it all with a belt sander to remove any dust or grit.
And only then does it go anywhere near my planers.
A lot of work but well worth the effort as studs and joists from a 150 year-old house that have sat covered in plaster for all that time is dry, tight grained from slow growth and just beneath the surface is the most wonderful colour so lacking in anything bought from a timber merchant. Sadly, most non-woodworkers are of the opinion I use reclaimed wood for economy
(although I also save any nails and screws
)
What is really important though, particularly if raiding a skip, is to salvage the wood and get it under cover ASAP as being so dry it will suck up rain like a sponge. I was approached once by someone who wanted a strange bespoke low boxed-in coffee table with storage made from some timbers being removed from his neighbours early Victorian terrace house. I agreed I would and told him to get the timbers into his garage immediately they were removed and store them until I could start work. When I collected them he assured me none of it had been left out in the weather and it machined well enough so I didn't doubt his word. Sadly, after construction, the top has shrunk across the field leaving a step where I'd attached the ends. When questioned my 'client' did confess rather sheepishly that he had left the wood out in the rain for a few days before getting it under cover. Still, they were delighted with the rustic nature of it and even asked me to make a smaller, more conventional, one.
Cheers,
John
