Yeah, learned this lesson the hard way myself. We built a custom dining table from reclaimed wood and thought air-drying would be enough since it seemed pretty dry already. Looked awesome at first, but after a season change, the tabletop started cupping and twisting pretty noticeably. Ended up having to sand and refinish it twice. Kiln drying isn't cheap, but neither is fixing warped wood later...lesson learned, lol.
Totally feel your pain on that—wood warping can be such a headache, especially with reclaimed stuff. One trick I've found helpful is to stack the lumber carefully with spacers (stickers) between each layer, and clamp or weight it down evenly while it's drying. It doesn't completely replace kiln drying, but it helps reduce twisting and cupping quite a bit. Curious, did you try anything specific to flatten your tabletop again before refinishing?
I've had similar headaches with reclaimed lumber, especially when I was trying to build some custom shelving for my home office. I did the sticker stacking method too, and it definitely helped, but I still ended up with a couple of stubborn boards that just wouldn't cooperate. Eventually, I resorted to planing them down a bit more aggressively than I'd planned—lost some thickness, but at least they were flat enough to work with.
Speaking of tabletops though, I've been curious about something: has anyone here tried using those metal C-channel inserts underneath to help keep things flat over time? I've seen a few woodworking channels swear by them, but I'm wondering if they're really worth the extra effort and cost. Seems like it could be a good solution for larger surfaces that tend to warp or cup over time...
I've seen a lot of folks recommending those metal C-channels lately, and while I get the appeal, I'm honestly not convinced they're always worth it. Sure, they can help stabilize larger surfaces, but in my experience, proper wood selection and careful grain orientation usually do the trick just fine. I built a pretty hefty dining table from reclaimed oak a couple years back—no metal inserts—and it's still dead flat today. The key was taking extra time to pick boards with stable grain patterns and letting them acclimate properly before assembly.
Plus, installing those channels isn't exactly a quick job. You've got to route out precise grooves underneath, make sure everything lines up perfectly... it can turn into quite the project. If you're already comfortable working with reclaimed lumber and have decent woodworking skills, I'd say you might be better off investing that extra effort into careful prep and joinery instead. Just my two cents though—your mileage may vary depending on your climate and wood type.
I see your point on careful wood selection, but climate can really throw a wrench into things. Built a small cabin wall last year—thought I nailed it with grain orientation and drying—but seasonal humidity swings still had it bowing slightly. Maybe those channels have their place after all...
