Reclaimed wood can save you lots of money, but there can be nails stuck inside that are tough to locate and remove. Here's a trick using rare earth magnets to locate the hidden buggers before they destroy your saw blade.
The eye test simply isn't good enough when checking for nails in pallets or reclaimed wood. Nail heads can easily shear off leaving a hunk of metal buried deep inside the wood. If you don't remove the nail, it can destroy a band saw or table saw blade as well as cause dangerous kick back.
Use a cluster of rare earth magnets tied to a fishing line to detect unseen nails. Pass it directly over the timber and look for it to pull one way or another. If it does swing then you've probably got a hidden nail that you can dig out.
How to remove nails [Jon Peters Art and Home (YouTube)]