A. Wood finishes expert Bill Feist responds: Most pressure-treated wood sold in lumberyards is treated with CCA (chromated copper arsenate). As metallic copper is both repellent and toxic to fungus, insects such as termites, and marine bi-valves this would preserve the wood and also act as an anti-fouling measure to prevent aquatic life from attaching to the ship’s hull and reducing a ship’s speed and maneuverability. The combination of latex primer and topcoat has been shown to give the best overall paint performance on treated wood.
One can divide the wood-preserving methods roughly into either non-pressure processes or pressure processes. Moisture enters the back, then lifts the paint as it tries to escape the front side. CCA-treated wood has little contact effect on growing plants and is safe for use as vine stakes and greenhouse flats. Water isn’t just soaking in the wood but it dramatically hinders the drying out process. To address this question, researchers at the Forest Products Lab (FPL) recently evaluated the ability of three common coatings to reduce leaching from CCA pressure treated wood.
If you are proficient using a paint sprayer, you could use that instead of a paint brush or roller. Treated wood tests are intended to provide relative corrosion information of items in contact with preservative treated woods and typically use humidity and elevated temperature to accelerate corrosion rates. The general appearance of wood treated with copper azole preservative is similar to CCA with a green colouration.
This means that a weather preservative is a must, and should be applied as soon as possible after your project is completed which will protect the lumber from less shrinkage occurs and the surface of the wood remains smoother longer. I enjoy painting and as you said, you can stand back and admire the work when finished. Outside you should wait 2-3 weeks before painting or staining in moderate temps with no to little rain.
Master bedroom, upholstered headboard, charming painted blue nightstand chests, rustic wood wall, Mr. & Mrs. Treated sawdust and shavings are not recommended for composting, mulching, or animal bedding, and the wood should not be burned except in approved commercial incinerators. For thicker material, the wood should be redried before it is placed in the structure if shrinkage would cause problems in use. The rapid growth of this species means that the wood is very porous and it moves.
That is why new deck boards and siding and trim that have been heavily or multi-coat painted on all 4 sides, thinking that will give the best protection, only last a few years versus the usual 10-20 years or so for boards that are painted top and sides only. Paint and solid-color stains, particularly in these applications, are likely to peel. She now works to assist people who have become sick from exposures to treated wood.
Solid finishes might also build up a film, especially after several coats, which can peel, chip, and crack like paint. While wood in contact with soil will generally decompose more quickly than wood not in contact with it, it is possible that the predominantly clay soils prevalent in Vietnam provide a degree of mechanical protection against insect attack, which compensates for the accelerated rate of decay. The wood should be dry before application, so the oil and solvent can soak into the wood.
The U.S. began mandating the use of non-arsenic containing wood preservatives for virtually all residential use timber in 2004. And because these new wood treatments are especially corrosive to aluminum, it’s best to use vinyl or copper flashing, or to wrap the wood in a protective rubberized membrane. This provides a ring of easily treated sapwood that forms a protective layer around the heartwood core. Pressure treatments force preservative into wood under higher than atmospheric pressures. Another big minus to paint: Because of the high humidity we have in South Florida, we have a lot of mill dew that forms.
Solid color stain will help extend the life of an older deck that is starting to crack and check. Your local home store or lumberyard is now selling lumber treated with less toxic alternatives… amine copper quat (ACQ) and copper azole (CA)… though you may find other chemical combinations in specific areas. End-user customers across the country are increasingly requesting treated lumber that has been stained. Many different commercial treatment methods have been developed to protect wood from deterioration.
Developed in the Philippines, this method (abbreviated HPSD) consists of a cylinder pressure cap made from a 3 mm thick mild steel plate secured with 8 sets of bolts, a 2-HP diesel engine, and a pressure regulator with 1.4-14 kg/m2 capacity. Epoxy Floor Coatings, Environmental Paints, VOC Paints, Paint Matching, Swimming Pool Paints, Wood and Concrete Floor Sanders. Because oil-type preservatives are insoluble in water, they are resistant to leaching and do not cause wood to swell during treatment. If treated wood is suitable for use in ground contact, it must be stated on the quality mark along with the designation LP-22.
The filler will accept paints and woodstains such as Cuprinol and Dulux Trade Woodstains, although the degree to which it may show through will be influenced by the preparation, the nature and characteristics of the wood as well as the type and application of the woodstain. In any case, with the treated wood, trapped moisture will simply make the paint peel back off long before any internal rot occurs due to the paint. The wood product is placed into a humongous cylindrical holding tank, and the tank is depressurized to remove all air.