Question I work as an upholsterer and custom furniture maker for commercial spaces (bars, restaurants). We mostly work in plywood but I've tried my hand at some personal projects using hardwoods. I built a custom credenza out of walnut about a year ago. The unit has 2 sliding doors on the front made of four pieces of 1/2" walnut laminated together. They use a simple tongue and groove for the track, and were finished with a tung oil wet sand. After the hot and humid DC summer the doors started to warp and bow outwards. They bowed so much in fact that one of the doors actually fell out of the out of the groove. I've since remade both doors, again at 1/2", and finished with a wipe on gel poly. But I've noticed that the new doors are starting to bow as well. I was careful to alternate the grain on doors and make sure both sides were finished with multiple coats (somethings I'm not sure I did on the first set). Is 1/2" too thin a material to use for these doors? Or is there something else I've overlooked? Any advice is appreciated. Thank you.
Answer Hey Evan, I'm confused as you say you "laminated" these doors, when it sounds to me like you just edge joined 1/2" planks side by side to make them...I'm guessing these doors are fairly large,or not, and likely, yes...they are too thin to maintain flatness. This ...as you know...is the reason engineered panels (plywood, etc..), are used for large panels like this, as a rule. Hard to believe they actually bowed so much they fell out, but another consideration is where you bought the Walnut..and what it's moisture content was when the doors were made, versus the relative humidity in the space the piece is kept.When flooring contractors install solid wood floors, they move the material into the space and leave it for many days, to acclimate to the room whenever possible, specifically for this reason. If you have any audio/tv/etc. equipment inside the piece..it acts like an oven, drying the interior of the space at a higher rate than the outside space, which will definitely cause issues...Winter spaces are notoriously dry, and very few people pay attention to the relative humidity in their homes, or any given space, and it's very important for the health and longevity of lots of things, wood furniture, leather, textiles, paper products, and of course living things as well. A simple Hygrometer, bought at any good hardware store, will likely surprise you with it's findings when installed in a given room. Most of our Winter spaces are way too dry, as a rule...and it's a full time job to keep a living space properly humidified. Museums and archival spaces know this too well, and it's at the top of their list when long term storage and care of important items is considered.
A finish itself will only slow down moisture transfer, as wood will always equalize itself to it's surroundings, so you cannot count on it to maintain the moisture content. It will help, but if you ignore the end grain...you're ignoring one of the most important areas for moisture loss/gain. Your design probably does not allow for battens to be installed on the back of the doors to resist warping, but that might be an idea. Hope that gives you some food for thought, please post back if need be...
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Thank you for the insight. Yes, I had meant edge joined and the doors are 20"x25". No room for battens on the rear of the doors. I might try an 1/8" plate of steel or aluminum to keep them straight and act as the tongue for the track, or come up with some sort of accordion door. Thanks again.
Questions on Woodworking, wood finishing and refinishing of all kinds, repairing furniture and wooden objects, Architectural details, Woodturning, carving, tool usage, product usage, some chemistry as it applies to woodworking and related interests,cabinet making and furniture construction/design, etc. I have experience with all manners of colorants, finishes, paints, stains, dyes, glazes, and coatings, wood species recognition and usage,tool recommendations, blade types and recommendation,techniques and methods for many Woodworking related issues, etc.
Fine furniture restorer and cabinet maker for over 30 years,serving high end Antique dealers, Interior designers, Collectors in the CT area. Consulting for area Painting/Decorating and Building contractors on non painting issues..(staining, wood prep.,clear finishing, floor restoration and architectural detail restoration and repair, etc.) Sold, built, serviced, setup Home, Industrial, and Commercial stationary woodworking tools for a major tool retailer in CT. for three years, sold hand and power tools , provided knowledge, parts replacement, service, and on site service, Trade show Demo, and training as well.
Publications Published in Fine Woodworking Magazine (12/97), included on Fine Woodworkings first "Best of Fine Woodworking" CD-ROM (2002) ...("27 year compilation of expert know-how")
Education/Credentials Art School at Silvermine Guild in Norwalk, CT., 9 year apprenticeship in a European run Cabinet and Restoration shop in CT., various classes on subjects having to do with the field. Seminars from major Tool manufacturers, Skil/Bosch, Delta, Powermatic, Ritter, Porter cable, Milwaukee, Dewalt/B&Decker, Performax.
Past/Present Clients Many varied clients including work on Martha Stewarts' Westport, CT. show house, many fine Antique dealers and private collectors in and around Fairfield County and in Woodbury, CT. (the Antiques capital of CT.), Golden Age of Trucking Museum,Consulting for area Painting/Decorating and Building contractors on non painting issues..(staining, wood prep.,clear finishing, floor restoration and architectural detail restoration and repair, etc.), local Museums and Historical Societies. For the last two years I have been employed with Schwenke Auctioneers Inc.- Woodbury Auction LLC., as a staff photographer,IT tech,and doing restoration and repair work as well.