I spend an incredible amount of time working with used wood around the farm. At one time I understand, there were many hog sheds on the farm(stead), and part of the clean up around here was sorting through piles of used 2x4's, 2x6's, and other lumber. Much of the wood was beyond further use, but I've gone out of my way to try and use everything possible. Most of the usable lumber has gone into repairing the barn.
Part of recycling the old boards and construction lumber involves removing nails, and I gotta tell you that the folks that farmed here apparently loved nails! You can read more on this subject in the archives about the Hammer Master if you missed it. For example I saved one 2x4 that had 40 nails in it. I've still got a good supply of old 2x4's, the ones that actually measure 2" by 4", not the stuff that is is 1 3/4" by 3 1/2" that is sold as a 2x4 today.
My current project around the farm is replacing the house interior trim. I'm fortunate that most of the oak flooring from the old hospital I'm working over for the project already has the nails removed. The problem is that I end up fighting twists and warped boards. Each board gets run through a planer for two reasons... removing the old finish with the planer is much easier than trying to sand the old stain and varnish off, and I quickly discovered that the old flooring manufacturer had quite a large tolerance for varying board thickness and the planer solves that pretty quickly too.
The other thing I've learned about working with old lumber products is that slivers are a fact of life. Yesterday I spent the day working on a fireplace surround and mantle, and today my hands feel like they were attacked by barbed wire. After spending some good construction time de-slivering my sore hands, I think I'm ready to dive back into the project. Now if I can just keep from putting a sliver back into one of the holes I just created in my hands removing yesterdays carnage, I'll have it made.