How to use reclaimed wood safely.
Using reclaimed lumber is a great way to reduce the carbon footprint of woodworking. You can use old fencing, pallets, or demolished home material. To stay safe and create safe products, proper precautions must be followed. Below, I will break down the rules I follow for using reclaimed lumber.
I see a lot of makers selling items made from reclaimed fencing material. If it is a cedar fence, or another naturally rot/pest resistant wood, this is a great option. A lot of fences, however, are made with pressure-treated lumber. Pressure-treated lumber should not be used for any indoor projects. Up until 2003, pressure-treated lumber was treated with chromate copper arsenate (CCA). CCA is linked to burning rashes, breathing problems, and neurological symptoms. My rule of thumb is, if I don't know exactly what type of wood it is, then I don’t use it.
Pallets are another great source of reclaimed wood. When using pallets, be sure to only use pallets with the IPPC stamp indicating the type of pallet. To prevent invasive species and plant diseases from spreading, the IPPC requires pallets to be treated. The IPPC requires markings to identify which treatment method was used. There are numerous treatment methods and markings. HT and KD are two markings you should look for and MB is one to avoid at all costs. HT stands for heat-treated and KD stands for kiln-dried. These do not use any chemicals to treat the wood. MB stands for methyl bromide. It is a pesticide that is linked to human health problems. This is not suitable for any craft projects or firewood.Here is the IPPC website with all the information.
In addition, you should also only use pallets that are free of spill stains. Pallets are sometimes used multiple times hauling all different products. There is no simple way to tell if a stain is from a hazardous material or not. So, play it safe and unless you know with 100% certainty what caused that stain, you should stay away.
Disassembly of the pallet is hard and, possibly, dangerous work. I have tried crowbars, pallet breakers, hammers, and reciprocating saws. Pry bars and pallet breakers haven’t worked well for me. I seem to crack the boards in half while trying to disassemble them. I tend to use the reciprocating saw with a bi-metal blade for pallet disassembly. First, I slide the blade in between the top boards and the rails. Then, I cut the nails in half. This does leave a portion of the nail in both pieces of wood, requiring an extra step to remove or make flush. The nail in the top board is easily hammered out with a punch. A picture of where to put the blade to saw is below. Unfortunately, there is usually no way to get the nail out of the rail board. If I need to have a nail-free rail board, I will take the pallet apart using a different method. I use a pry bar or pallet breaker and ease up one side of the top board slightly. Then, use the reciprocating saw to cut the nail off flush with the top board. This will leave a bit of the nail hanging out on the rail board, which you can then use a nail puller to remove. Another option would be to cut the top board flush with the rail and then us the pallet breaker or pry-bar to pull out the nail. I use all three methods depending on my project.
When using demolition site lumber, the first question to ask should be: is the demo being done by a professional or a d-i-y? I am all for D-I-Yers, but not all of them do proper research. If they are uninformed, they may unknowingly be demolishing a building with lead paint or one with asbestos. These are extremely hazardous materials and need to be avoided. So the next question should be: when was this building built? Both asbestos and lead were banned in the ’70s, so if the building they are tearing down was built in the 1980s or newer it should be safe. The third question I ask is: who built this building? A licensed builder would follow all building code guidelines and be inspected during construction. If the building, though, was built in the ’80s by a d-i-yer, then they may have had old paint with lead in it or asbestos material laying around and used those in the construction. It is up to you how much risk your willing to take. I would still suggest to always test any paint before sanding. They sell test kits for both materials at a big box store or online. Also, remember, once lead paint or asbestos is disturbed it becomes the most hazardous. I stick with working with professionals because they, by law, have to test for both products beforehand. This still isn’t 100%, but I find it to be the safest way. I still, also, do a lead paint test at home on any paint I have to remove before removing it to be extra careful.
When using any reclaimed wood there may be things inside the wood (nails, screws, staples, etc.) that you don’t know are there. I use a high powered magnet to rub over the wood as I am preparing the wood, in order to find them. If I find any hidden hardware, I will pull them out if I can or mark them with a sharpie so I don’t accidentally run a blade into it. This is not a foolproof plan, but it does help to reduce the number of dull/broke blades dramatically. Going further on this idea, if you are using a table saw and you hit a foreign object while cutting, this may cause a dangerous kickback or a binding of the blade. So, be cautious and use proper protection and tools. I try to use a bandsaw whenever sawing reclaimed lumber to reduce the risk of mechanical safety issues.
Finally, wood is porous and can harbor bacteria, mold, or animal feces. A good cleaning with bleach and water is advisable. Allow enough time for the wood to completely dry before using.
I hope this article has helped you. Please, if you have other tips, tricks, and safety ideas write a comment to share.
Top: Shows where to saw with the reciprocating saw.
Bottom: Shows where to cut the top board to get a nail-free rail board.