Recycled Lumber: How do I prepare reclaimed lumber to use it?


You have been fortunate enough to get your hands on a pile of recycled lumber from an old building. It has a rough surface, dirty, has nails and nail holes in it. How do you clean it up into nice straight dimensional boards, with a surface planner right? Yes, but not so fast there are a few other steps involved.

Before diving into planning up the lumber, you need to get all of the foreign material out of the wood including dirt and nails. Dirt will dull the planner knives in a hurry and nails will take out a chuck of a planner knife. I have unfortunately planned over a nail and ruined a brand new set of planner knives. The only good thing was that the nail was on the edge of the board and nicked the planner knife on the outer edge about 3/4 of an inch. So, I was able to run narrower boards down middle of the planner.

Step 1: Metal Removal

Make visual pass over all sides of each board looking for nails and any other debris. Now is a good time to get a hand held metal detector. You can pick up a good quality unit for around $100. Not cheap, but compare it to the cost of replacing a set of planner knives damaged by hitting a nail?

Planning over a common nail made from soft steel will take a chunk out of the planner knife. Planning over a square nail will significantly damage the planner knife. Square nails from 100 years ago are made from much harder steel.

Step 2: Dirt Removal

Remove all of the dirt and particulate matter from the lumber. Even if the lumber is free of obvious dirt it is worth the extra step to run a belt sander over both sides of the board with a 60 or 100 grit belt to remove any sand, dirt and particulate matter.

Step 3: Squaring up one side

This is where having a joiner becomes very handy. If the board has a twist in it, a planner will follow the twist while planning. The planner will not plane out the twist. Make several passes over the joiner one side to remove any twists in the lumber.
A stationary belt sander may help in removing some of the twist in the board, but not all of it. It can only remove the portion over the span of the belt.

Step 4: Planning the lumber

With one side flat the lumber is ready to be planned to the desired dimension.

Step 5: Square up the edges

Square up the edges with your joiner.

Start having fun building your latest project!