A Few Words About Shop Humidity

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If your shop is heated, then it is also dry. A lack of humidity in a woodshop is often problematic but it's especially troublesome for veneer users. If you are working with veneer in a very dry environment, then you have two options.

Dont Let This Happen in Your Shop

Option 1- Install a Humidifier
They are not expensive. I recommend the Skuttle brand of steam humidifiers. Adding humidity back to your shop will make it feel warmer but more importantly it will prevent stress from forming inside a veneer and a veneered panel. It will also extend the open time of most veneer glues.

Option 2- Don't Install a Humidifier
But be prepared to deal with some issues. Here is how low humidity affects a veneered panel.

  • Wood veneer is organic so it will expand and contract with humidity changes in your shop. And because veneer is so thin, the moisture content in it will quickly change quickly. If the shop is dry, the veneer will be dry and the wood cells will shrink. When the veneer is placed onto a freshly glued substrate, the veneer will absorb the moisture from the glue. That creates two potential problems... a) the veneer will have a tendency to warp and ripple quickly (caused by the wood cells expanding with the added moisture) which could create a rippled panel if there is not enough clamping pressure. And b) if the glue loses too much moisture before the full clamping power is applied to the panel, then you might get a less-than-perfect bond. The wetness is what gives the glue its bite.
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  • Most substrates like MDF, particle board, and plywood are organic as well. If the substrate is exceptionally dry, the moisture from the glue will be absorbed which can cause the glue to "set up" before the veneer is applied. Again, the wetness is what gives the glue its bite.
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  • The completed veneer panel is therefor also organic. It will shrink after the moisture from the glue has evaporated into the shop air. Excessive dryness will force the veneer to contract/shrink quickly and when that happens, the panel can warp or the veneer could crack.

Take a minute to buy a decent humidity gauge. If your shop is under 40% relative humidity, then I'd recommend adding a full time humidifier. It will be worth the effort to save your lumber, veneer, and your finished projects.