The Old Forestry Mixture

The old forestry mixture, as some have called it, is a formula for a penetrating oil stain developed by the Forest Products Laboratory in the 1950's. Other than the old forestry mixture, it's more formerly know as the Forest Products Laboratory Natural Finish. The FPL Natural Finish was introduced as follows:

"Many homeowners want a finish that retains a part of the natural color and the grain of new wood or one that enhances the rustic appearance of lumber or plywood. The commercially available natural finishes that form a clear film, such as varnish, have been so short-lived, however, that they are not recommended for exterior use. One durable natural finish is the penetrating stain, developed at the Forest Products Laboratory in the 1950's. The FPL natural finish was formulated to overcome the more serious shortcomings inherent in such finishes of t the film-forming type that are so susceptible to failure by cracking ind peeling. Because the stain penetrates the wood surface and does not form a coating, there is no failure by blistering and peeling even in excessive moisture conditions. There is no coating to scrape before refinishing. Thus, the penetrating stain is easily maintained at a low cost on a variety of wood surfaces. Test results indicate that the first application of the FPL natural finish to smoothly planed surfaces fully exposed to the weather should last I about 3 years. When refinished after weathering, the finish will last much longer. Two coats of stain applied to rough-sawn or weathered surfaces may last 10 years or more."

The exact recipe and full document are listed here. It contains a blend of linseed oil, paraffin wax, solvent, and some other ingredients, including Penta, which is no longer available to the public and restricted to things like the manufacturing of telephone poles and railroad ties. While some of the ingredients are difficult to obtain and Penta is nye impossible, there is at least one alternative on the market. As a ready-made option, a formula similar to that old mixture is available under the brand Organiclear WR-5.

WR-5 Log Home Stain is a superior exterior wood treatment that restores, preserves and enhances the natural beauty of your new or existing log home, deck, fences, railings, shakes and shingles, and outdoor wood furniture. WR-5 offers a unique blend of deep-penetrating premium oils, resins and waxes to create a long-lasting MOISTURE-GUARD™ barrier against harsh weather. To enhance wood life further, WR-5 provides maximum protection against ultraviolet (UV) radiation damage by combining sun blockers to absorb and control UV degradation, thus minimizing wood deterioration. WR-5 penetrating coating will also help prevent wood from cracking or peeling. WR-5 also works very well in high humidity areas. WR-5 allows wood to "breathe" naturally through a micro porous film and prevents moisture penetration. Water beads up and rolls off the exterior wood surface. WR-5 brings out the natural grain beauty of the wood while preventing the wood from cracking and peeling. WR-5 is the perfect choice for the full realm of wood protection your home needs to stand the test of time. For new, unfinished decks, apply two coats of WR-5 this year and then either a third in the Fall or one more next year. WR-5 Clear can be used as a second (if only putting on two coats), third coat, or as future maintenance coats though it won't last as long as a pigmented coat. Some people like to use the clear in this way to "lock" in a particular light color. Made in the USA.

Log Rot: The Problem With Painted Logs

Log Rot: The Problem
With Painted Logs

This log house was originally coated with house paint instead of a Log Home Finish. You can see where the house logs have cracked or "checked" leaving open cracks in the paint for rain water to penetrate into the wood causing further log rot. The density of the paint coating acts like a plastic sheeting that traps in moisture causing blisters and flaking paint. In winter when the logs freeze, the trapped moisture expands by becoming ice particles. This causes more subsurface damage making tiny cracks larger and allowing more space for water to penetrate farther into the log causing more damage. In the photograph, the dark area behind the pipe is totally rotted.

In a situation like this all of the paint needs to be removed with either a chemical stripper or blasted with media (glass is most common now). The next step would be to cut out the rotted areas of wood and use Tim-bor or Boracol to saturate the logs and keep them from rotting any further. If the rotted areas are relatively shallow, LiquidWood can be used to seal cracks and create an undercoating for the WoodEpox to adhere to. Next, apply the WoodEpox and form it so that it conforms to the rest of the log. Dry pigment can be added to WoodEpox to color it (especially if you will be coating with a stain). Allow to dry thoroughly, then apply a new finish.

If large portions of the logs are rotted away, you will either have to replace portions of the log with half-log inserts or replace the entire log. You may need the services of a professional log home restoration contractor.

For DIY advice or restoration contractor referrals, call Schroeder Log Home Supply, Inc., at 1-800-359-6614 or contact electronically here.

A Few Notes to Consider on Deck Stains

Walking traffic, direct sun, and standing water make decks higher maintenance than log walls.

Most log home finishes are too soft for use as a deck stain. Use a finish rated for decks.

Clear finishes are more prone to UV damage and have shorter lifespans than pigmented finishes on decks and log walls.

For matching the house stain to the deck consider LifeTime, Sansin, Sikkens (ProLuxe), Transformation, WeatherSeal, WR-5, or X-100 Deck.

Inspect areas where the deck meets the log walls. This area can be a problem area for wood rot. Water runs down the deck to the log wall. Flashing will solve this problem where the deck meets the wall.

Contrasting colors of deck stain to the house can be attractive - e.g. light honey colored house, dark honey colored deck.

Pressure treated or green treated decks can be stained, but wait 3 months to 1 year. This allows the wood to dry and the green color to fade. This will give a more true color to the stain that you purchased.

Cedar decks stand up better to the weather but they still need a water repellent, pigmented finish. All wood rots when conditions are right.

Railings are high maintenance; watch the tops of log railings for sunburned and water catching depressions.

Be careful of cedar railings that were strip peeled. Strip peeling (removing the bark without using a drawknife) can leave a thin layer of cambium that will peel off prematurely, making it appear that the stain is peeling. Also, the closed wood pores can repel the log or deck stain's ability to adhere.