You Can Steam Bend Kiln Dried Lumber
Do not throw rocks at this sign.
My eighth grade teacher Mr. Knox put a sign in the parking lot that said “Do Not Throw Rocks at This Sign.” He put it there to prove a point that if you tell a kid not to do something, most likely they will want to do it. He was right. By the end of the week, the sign was demolished.
Maybe it is the kid in me or I’m just the rebellious type, but when a friend told me it is not possible to steam bend kiln dried lumber, I just had to try. My plan was to create a wooden handle that had three tight bends in it. Of course, my first try splintered along the outer radius of the bends, proving my friend right.
Apparently, when wood is kiln dried, the lignin in the wood dries out and hardens, not allowing it to bend. Now, I am not a biologist, so I may not be qualified to explain exactly what lignin is. However, the same friend who told me you can’t steam bend kiln dried lumber provided me with this definition. Lignin is an organic substance binding the cells and fibers in wood together. By the way, he is not a biologist either.
Not letting his explanation stop me, I set out to do my own research. I didn’t waste any time researching things that would tell me I couldn’t do it, like studying what lignin is. I did however find an old Woodwright’s shop episode were Roy Underhill showed how to use a metal strap during the bending process to compress the outer fibers, preventing them from splintering.
Now the wood Roy used was not kiln dried, but his technique was what I was interested in and I thought it was worth a try. I headed off to the hardware store to find some flexible metal. It turns out they don’t really sell anything that I thought would work. Feeling defeated I headed towards the door to leave when I spotted a piece of metal banding sticking out of a trashcan. Not wanting to be tackled in the parking lot for stealing their trash, I found an employee and asked if I could have it. While giving me an odd look, he said “sure”. I headed back to the shop to test it out. On a side note, after showing my friend what I was using to prevent splintering, he suggested using metal strapping that plumbers use to secure pipes and ductwork, which can be purchased at most hardware stores.
It took me a few practice runs to figure out how to keep the metal banding tight against the outside curves where the most splintering could happen. After some practice, it worked out pretty well. It didn’t stop all of the splintering, but the little parts that did splinter were easily sanded off.
I have seen some elaborate setups for building steam boxes; however, my setup for this project was simple. Since the piece I wanted to bend was small, I just used a trash bag to contain the steam. To generate the steam, I snuck into my wife’s closet and got the little steamer she uses to steam out the wrinkles in her clothes (let’s keep that part on the down low). I stuck the end of the nozzle in the bag, taped it shut, and let it fill with steam for 30 minutes before pulling the piece out and bending it into my form and clamping it.
When I showed my friend my accomplishment, he didn’t readily admit to defeat. He said, “The handle is only 1/8 inch thick, it is like a bent lamination.” On the other hand, unlike a bent lamination where the gluing of the layers are what holds its shape, this is only one piece of wood and no glue. It is holding its shape all on its own. The two outer curves are almost at a 90-degree bend, which is tough to do even with a 1/8 inch thick piece of wood. In the end, whether or not I am rebellious or just determined, I ended up with a beautiful steam bent handle.
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