EMC/RH ratios Here's a listing of equilibrium moisture content to relative humidity ratios. July 11, 2000
"Intermediate Conditioning" in the Drying Kiln Is it a good idea to add moisture to a kiln for a period during the middle of the drying cycle, in order to relieve casehardening stress? June 13, 2014
Is Kiln Drying to 7% Worth It? Why kiln dry wood to 7% moisture content when it will gain moisture in storage? Here's an informative thread about proper drying targets and storage based on the intended end use of the lumber. December 31, 2013
Door Gap and Outdoor Humidity A woodworker gets expert advice on predicting the moisture-related dimensional changes in a wood door, for purposes of calibrating the door gap to allow for the movement. October 11, 2007
Developing Software to Calculate Wood Kiln Schedules The wood drying process is complex, and involves many inter-related variables. So creating software to determine drying schedules is a challenge. June 13, 2014
Ambient Humidity and Wood Moisture Content A problem of wood warping in a dry basement storage area leads to a discussion of temperature, relative humidity, and wood moisture. July 10, 2007
Furniture for High Humidity Conditions Advice on controlling moisture content during construction for furniture destined for a relatively uncontrolled environment. November 15, 2010
Drying Rewetted Kiln-Dried Lumber How to render kiln-dried lumber, which has been rewetted due to flooding or excessive humidity, useful once again. 1998.
Air-drying oak Can a suitable MC for cabinet construction be reached? February 6, 2002
Mist systems and relative humidity Mist systems, what they do, and some general information about relative humidty and its effect on wood. 1998.
Indoor Humidity and Wood Moisture Content A discussion with data, about typical indoor humidity levels and the corresponding effect on wood moisture content. October 13, 2010
Wood Movement Destroys Table Top Another designer learns the hard way, as a table top cracks because of ambient moisture changes and restrained wood movement. May 3, 2011
Moisture and Swelling Issues for a Porch Ceiling Moisture-related expansion could cause beadboard porch ceilings to buckle. Why, and what can be done about it? This long discussion delves deep into the mysteries of moisture. February 8, 2008
Raised Panel Shrinkage Cabinetmakers grapple with the issues raised by installing unfinished cabinetry in an unheated house, mid-project. May 28, 2010
Why Does Plywood Warp? An extended technical and practical discussion of dimensional instability in plywood panels. January 20, 2010
Measuring Air Velocity in a Kiln Airflow is usually measured exiting the kiln. Here are some details on good practice. June 13, 2014
Wood Moisture Content and Equalization Understanding how to evaluate wood moisture content when conditions have created a moisture gradient within the wood. April 11, 2008
Size effect on shrinkage Are traditional shrinkage values applicable to drying large cants? May 9, 2001
Moisture content for exterior doors Determining the appropriate MC for lumber that will be exposed to vastly different humidity levels. November 14, 2001
Temperature, Humidity, and Drying Some generic head-scratching over relative humidity and the heat required to dry wood under various conditions. April 10, 2007
Hairline Cracks in Kiln-Drying Cherry Checking in Cherry appears as a fine crack, and is the result of too-fast air-drying, not kiln-drying. April 15, 2012
Shop-Drying Eucalyptus Thoughts on how to dry and condition Eucalyptus for use in a table top. December 31, 2012
Protecting Cabinets from Changing Humidity Details on how shop humidity, jobsite humidity, and occupied home humidity vary, and advice on helping cabinets withstand the changing environment. January 21, 2007
A Spalted Slab in a Wine Cellar Kiln-drying kills the fungus in spalted wood, and 60% RH in a wine cellar will not support fungal re-growth. December 6, 2011
Setting Shop Temperature A long discussion about how warm (or cool) to keep a shop, whether to turn the heat down at night and over the weekend, and the effect on costs, productivity, and quality of different practices. December 24, 2012
Controlling Drying Conditions and Monitoring Progress Here's a lively, sometimes contentious, and very informative thread about how to ensure quality control when drying lumber in a variety of different kiln types with different control systems and instrumentation. July 16, 2012
Dealing with Bowed or Warped Plywood Warped, bowed, cupped, twisted — these days, plywood seem to lie every which way but flat. Here's a long and somewhat technical discussion of what makes plywood deform, and what can be done about it. December 28, 2005
The Dimensional Effects of Wood Moisture Understanding how moisture interacts with wood can help you avoid problems from moisture-related wood movement. September 13, 2012
Flooring Joint Profiles Is it okay to saw strip flooring with a flat shoulder joint instead of a V groove? June 4, 2012
Troubleshooting Drying Stress Some general instruction about the causes of drying stress for the owner of a dehumidifier kiln. April 2, 2013
Drying with Moderate Heat Here's info on how various types of wood will respond to conditions in a home-built drying room that doesn't get much warmer than 120°F. There's a useful lecture here on how case-hardening occurs. May 16, 2008
Quality Control for Picture Frames The fine art of woodworking: a discussion of wood choices, moisture control, and other key issues involved in creating picture frames that will be stable in service.June 12, 2014
Steaming, Drying, and Honeycomb in Walnut Bacterial infection as well as steamer and kiln settings may have caused reported honeycombing at one end of thick Walnut boards. June 18, 2009
Will Stacked Lumber Gain or Lose Moisture? Lumber in storage may gain or lose moisture, but very slowly. Wrapping the pile in plastic will slow or stop the moisture change. March 29, 2006
Shop Temperature and Wood Machining Is it okay not to heat the wood shop at night? Could be, but humidity changes are a potential problem. August 26, 2008
Lumber Grading, Quality, and Small Mills Here's an extended discussion of the public policy issues involved in lumber grading, and construction using un-graded lumber, as seen from the point of view of the small sawmill operator. May 18, 2010
Crack Prevention and Repair for a Large Wood Turning Here's a long, thoughtful technical discussion of humidity conditions, wood cracking, prevention, and fixes, focused around the case of a very large wood turning that has developed hairline cracks. January 20, 2011
Paint Cracks in Five-Piece Doors Some cracking is pretty much inevitable when you paint five-piece wood cabinet doors. September 25, 2014
Wood Movement: How Big a Risk? In principle, solid wood joinery that does not allow for wood movement is a recipe for disaster. In practice, sometimes you get away with it. June 18, 2009
Drying Koa Insight on the ins and outs of drying Koa wood in Hawaii. April 20, 2011
Air-Drying Wood in a Grain Bin A discussion of air-drying sheds light on issues relating to target moisture content. July 28, 2008
Properly Drying Oak for Use in a Porch Swing Thoughts on air drying, kiln drying, and conditioning for oak intended to be used in outdoor versus indoor conditions. January 11, 2007
Lumber Conditioning Advice Info on mixed loads, re-wetting dried lumber, and related topics. September 25, 2014
Venting and Fans for a Solar Kiln A quick expert explanation from the Wood Doctor of how and why vents and fans are used in a solar wood drying kiln. April 20, 2011
Using OSB for Stickers Sawmill pros generally frown on using oriented strand board (OSB) for sticker material. January 17, 2011
Dark Core in Soft Maple A kiln operator finds that his maple boards develop a light surface and dark core. Others weigh in with thoughts and advice. August 31, 2005
Redrying 4/4 Hard Maple Tips for re-drying a load of wood that got wetted by rain, without incurring damage. December 31, 2013
Winter Drying of Lumber in a Barn A quick description of the factors affecting drying time of wood stacked in a barn for the winter. July 16, 2012
Troubleshooting Glue Line Swelling in Furniture In this long and complicated thread, woodworkers and experts try to figure out what's causing a slight ridge to form at the glue line in a wood chair lamination. July 29, 2014
Glue Joint Movement — Causes and Cures Here's a wide-ranging discussion of adhesive properties and glue joint behavior, triggered by a specific problem involving a raised glue line in a Cherry countertop. October 19, 2014
Self Air-Drying Versus Kiln-Drying Carefully air-drying wood yourself may be preferable to trusting the load to a less-than-perfect kiln-drying operation. January 18, 2011
Accuracy and Tolerances in Humidity Measurement in a Drying Kiln Super precision is rarely critical in wood drying, but reasonable accuracy is helpful. Here's a discussion of RH measuring precision, and its importance for maintaining proper real-world kiln conditions. July 29, 2012
Allowing for Wood Expansion in Solid Board Paneling A woodworker puzzles over the measures needed to let V-groove wood board paneling expand and contract with seasonal moisture changes in a seaside home. January 2, 2012
Ideal Humidity in a Wood Shop Indoor humidity levels correspond with wood moisture content. Here's advice on humidity control. October 26, 2012
Lumber Moisture Content and Glue Failures When you cross-cut and rip lumber at too high a moisture content, then quickly glue up panels (such as stair treads), glue failures may soon occur. February 5, 2007
Time to Air-Dry Thick Lumber Many variables affect drying time. Here's a discussion about the typical drying-time window. November 16, 2011
Wood Heat for a Shop Wood stoves in a shop introduce concerns about safety and about excessively dry shop air. January 20, 2010
Black Walnut for Windows A discussion considering whether Black Walnut is an appropriate wood for constructing custom reproduction window sash. April 4, 2011
Re-Drying Wood from Outdoor Storage Advice on how to best restore wood to useability after it has been left partially exposed to weather in a shed. January 18, 2011
Dehumidifier Kiln "Hanging Up" Dehumidifier kilns sometimes stall as moisture content readings get closer to the target. An extra shot of heat can help a lot. July 3, 2008
Commercial Countertop Shrinkage A very long laminate countertop in an industrial loft buildout experiences movement problems because of humidity changes. January 12, 2012
Whether to Glue Panels to Stiles and Rails The basic answer is no (don't glue door panels to frames), but there are some fine points raised in this discussion. November 15, 2011
Control Issues in a Dehumidifier Kiln If you run the kiln too hot, a safety cutoff may shut down your compressor, interfering with the drying process. April 27, 2007
Why is Wood Flooring Kerfed on the Bottom Face? Speculation, theories, and facts about why wood flooring and some door jamb stock is usually milled with grooves in the underside or back side. October 13, 2008
Vacuum kiln drying How do vacuum kilns work and how effective are they? (From WOODWEB's Sawing and Drying Forum) January 21, 2003
Door Construction and Wood Movement Experienced pros try to educate a newcomer about the power of wood movement and the necessity of allowing for it in constructing complicated assemblies such as architectural doors. May 12, 2013
All About PPR Glue Want the low-down on Powdered Plastic Resin glues? Here's everything you need to know. October 20, 2005
Laminate and Substrate Movement A question about what might cause melamine laminate to pull loose from a countertop leads to an in-depth look at the materials involved. April 18, 2006
Wide Miters in Wood Countertops This long discussion about a proposed custom project includes good explanations for why miters in wide solid wood don't work, and some suggested methods to use instead. November 14, 2014
Miter Joinery in a Wood Countertop In principle, a miter joint in wood is problematic because of moisture-related expansion and contraction. But some installers say that if the whole countertop is left free to move, the joint will be okay. January 25, 2013
Cupping, Bowing KD VG WR Cedar? More fun with wood moisture: Figuring out why some supposedly kiln-dried cedar boards cupped and bowed after being resawn and planed. January 26, 2008
Air-Drying and Kiln-Drying 8/4 Oak Experts and kiln owners discuss the proper drying schedule and the best equipment for drying thick Red Oak boards. August 13, 2014
Oversize End-Grain Butcher Block Woodworkers kick around the issues raised by a client's proposed DIY project: a 4-foot by 7-foot butcher-block top. October 2, 2007
Regaining MC in overdry wood Is machinability lost when lumber has been overdried, then had moisture put back in? May 17, 2003
Sizing Up a Kiln This question about how to assess the worth of a used kiln leads to a discussion of kiln technology in general, including the different requirements for drying softwoods and hardwoods. October 17, 2012
Re-Drying Kiln Dried Lumber An architectural woodwork mill gets advice on acclimating stock before machining it. December 9, 2010
End Checking in Beech Blocks Drying cracks in imported Beech blocks may be the re-opening of existing cracks, related to changes in atmospheric relative humidity. November 27, 2007
Drying Lodgepole Pine in Colorado Detailed advice on air-drying and kiln-drying lodgepole pine (some logged green and some killed by beetles). April 21, 2008
Door Finishing and Wood Movement Thoughts on how to prevent bare wood from being exposed when door panels and frames shrink during dry seasons. November 13, 2009
Heat Up Rate in Lumber Drying Most wood-drying situations don't require careful control of the rate at which the load heats up. June 13, 2014
Tension Set and Lumber Conditioning Advice on remediating curved lumber after resawing, with a discussion of why "tension set" occurs and how the effect can be reversed. October 19, 2013
Long-Term Storage of Air-Dried Lumber Air-dried lumber left in drying stacks for long periods without kiln-drying is at high risk for insect damage and spoilage. June 18, 2010
Moisture Content of Western Red Cedar A stable wood that is typically serves exterior uses, Western Red Cedar is usually delivered at about 12% moisture content. But you can find it drier than that. July 28, 2006
A Humidity-Controlled Display Case A cabinetmaker gets advice on appropriate details for a climate-controlled display case for musical instruments. October 8, 2005
Warping, Moisture, and Wood Shape Memory Will a piece of wood that was restrained to prevent warping during drying warp later, while in use? Only if the moisture in its environment varies. October 30, 2005
Kiln Drying Gum Sap Gum and Red Gum should be dried separately using different schedules. January 2, 2012
Mitering a Solid Wood L-Shaped Top A discussion of the risks inherent in building a corner into a solid wood table or counter top. April 24, 2014
Raised Glue Lines after Sanding and Finish Moisture in glue can cause swelling of wood near the joint, which may result in noticeable lines at the joint (depending on the timing of sanding and finishing). October 19, 2014