Mike
As Charlie said, it depends on the type of finish that you are using. As a general rule of thumb wood should always be very low in moisture content when you apply a finish. Depending on the time of year and frequency of rain, relative humidity and exposure of the wood itself the time it takes to dry will vary widely.
Typically oil based finishes require the lowest moisture content. Products like Woodrich Brand Timber Oil and Ready seal which are primarily paraffinic oil based will require a moisture content as low as 12 - 15%. (Check with product manufacturers for exact specifications)
Some of the water based formulations are more tolerant to moisture but again this depends on each individual products formulary characteristics. We offer Wood-Tux and Woodrich Brand Stain & Seal in an oil based formulation that can be applied directly to wet wood.
As Charlie said, even though you can apply Wood-Tux successfully to soaking wet wood, you get a richer finish by allowing the wood to dry slightly at the surface. Woodrich Brand Stain & Seal, while compatible with wet wood application, will typically require a two coat application when working with wet wood. Both products utilize ESI's WET technology however the higher resin content in Wood-Tux allows it to perform better in wet conditions.
For more information, you can check out
www.esproducts.net and click on wood restoration.
While you may not always depend on a moisture meter, I think I would recommend it's use to anyone who is new to wood restoration. It will help you to limit your learning curve by gaining a better understanding of the drying processes of wood. You will probably be very surprised at how difficult it is to allow wood to dry to the 12 - 15% mark. This is especially true during the rainy seasons in the spring and fall and in those areas like the North East and Pacific North West where temperatures are not as favorable.
Best of Luck
Russell Cissell
Extreme Solutions, Inc.
www.esproducts.net
imrcc1@aol.com
636-288-8512