Environmental Application is Extremely Important
Wood veneer, like all natural wood materials, is affected by changes in the environment. Temperature and humidity have the greatest impact on wood movement and ultimately surface failures.
There are several things to take into account when selecting, storing, assembling and finally putting your project into service.
Relative humidity and temperature
- Here in the Midwest we are a full-on 4-season climate zone. It gets very cold and dry in the winter, and then shifts to a more humid climate in spring, and then extremely warm and humid in the summer then into fall and winter we start the cycle all over again.
- Depending on the time of year and your location the first thing you need to do is to acclimate the veneer to your environment.
- The purpose of this is to bring the veneer to a point of “Equilibrium Moisture Content” or EMC. EMC is the point where wood is neither taking on nor expelling moisture.
- When the climate dries and humidity decreases wood will shrink and the reverse is as humidity rises wood expands, so the object is to allow the wood to reach equilibrium before attempting any assembly.
- Average acclimation times for veneer are right around 4 days in most cases.
- Ideal humidity conditions for a great part of North America are between 30% and 50% relative humidity for woodworking and ideal temperature is right around 65ºF.
- First and foremost an attempt should be made to have your work area somewhere around the conditions listed above.
- Once materials arrive give them adequate time to acclimate to these conditions. Certain species and veneer cuts and grain patterns (for example Hickory and Beech), will need even more time because they are even more affected by humidity.
- Then, and this is an extremely important part, know what the conditions are for where the veneer will be installed.
- Going from two distinctly different climates ruins more jobs than just about anything else.
- It is highly recommended that you should invest in a psycrometer, which is a device that measures humidity and temperature. The average cost is around $30.00 so it’s worth its weight in gold.
- Measure the conditions where you will be doing any assembly as well as where the project will be installed and make sure you don’t have too big a difference between the two. Obviously they will not be identical or perfect but these issues can be communicated to all parties involved so problems can be addressed before any work is done. Also it will have an impact on your method of application.
- If installing a piece in an area that has less than ideal climate conditions, it’s imperative to think about how you need to apply the veneer to the substrate to achieve the best results.
BEFORE you begin ACCLIMATE, ACCLIMATE, ACCLIMATE!