Coating prior to assembly is not an option for us, since this will disguise the type of wood used so that - during an inspection - a customer is unable to verify what type of hardwood is used. This is in particular true for dark coats. It will therefore remain a guess by the customer whether the proper wood was used, whereas he needs to rely on the liability of the manufacturer. In order to close out any uncertaintly we do NOT coat the unit prior or during the assembly process so that a customer can always and at random verify the type of wood used during an inspection.
Another reason not to coat the wood prior or during the assmebly process is based on Based on research performed by Akzo Nobel’s Sikkens © coating division. We learned that kiln drying of some species such as Bangkirai prolongs the extraction of tannins and other extractives that, if left in the wood, will ultimately result in failure of any finishing method.
The coating system that we apply is based on water based Acrylic. The advantage of water based Acrylic is that they are ideal primers and have excellent adhesion. The low drying time is a major advantage. Water based finishes, in theory, are a more durable product than oil based coatings because it acts like a hard protective shell of plastic coating, sitting on top of the surface of the wood like paint. Because it goes down like paint, the applicant tends to have a greater reflection and shine.
ADDITIONAL INFORMATIONFOR THOSE WHO WANT TO KNOW MORE ABOUT OUR COATING SYSTEM
A. WHY WE DO NOT COAT OUR WOOD PRIOR OR DURING ASSEMBLY
There are 2 good reasons not to coat wood prior to or during the assembly process:
|1.||When coated the customer cannot verify what type of hardwood is used during an inspection. This is in particular true for dark colors. When a client orders and pays for Bangkirai he shall get Bangkirai, or Merbau, or any other type of wood ordered and paid for. However any type of wood which is coated cannot properly be verified on the type of the actual wood species used, unless it is cut and the coat taken off. Cutting a part of a beam or siding installed in the unit is not an option, while scraping off paint needs a relatively large area to be cleaned. Painstaking and time consuming. It will therefore remain a guess by the customer whether the proper wood was used, whereas he needs to rely on the liability of the manufacturer. In order to close out any uncertaintly we do NOT coat the unit prior or during the assembly process so that a customer can always and at random verify the type of wood used during an inspection
NOTE: Prior to the assembly of a unit we supply some samples of the wood to be used for the unit, so that a client can easily verify during his inspection whether the proper and genuine wood was used
|2.||Based on research performed by Akzo Nobel’s Sikkens © coating division, we have learned that kiln drying of some species such as Bangkirai prolongs the extraction of tannins and other extractives that if left in the wood will ultimately result in failure of any finishing method.
All hardwoods should therefore be left uncoated for as long as possible, and be air dried in the open (for instance during the assembly process) until all extractives have leached from the timber fibers and the timber is thoroughly dry (*). For oily resinous timbers such as Merbau a minimum of 3 months is recommended. For very dense, slow drying timbers such as Bangkirai a minimum of 6 months is necessary. During this seasoning period we must regularly clean all wood surfaces to remove the extractive materials that leach from the wood as it seasons such as tannins, as well as ensure that the moisture content stabilizes and adjusts to the surrounding climatic conditions. The method for regular cleaning is critical and if not done properly or carefully can damage the wood and affect its termite resistance. It is therefore not an advantage at all to assemble a wooden prefab house under cover since weathering will be prevented (no sun, no rain) and thus the proper drying of the wood is at stake (*).
In conclusion: Prefabrication carried out in the open has major advantages with respect to the holding and lifetime of the applied coating.
(*) Source: Akzo Nobel Sikkens, Australia
Based on the two reasons above we do not coat our wood during assembly, but will do this in average about 2 to 3 weeks prior to shipment
B. WHAT IS THE TYPE OF COAT THAT WE USE
The primary purpose of paint is to protect wood from deterioration. To do so, paint manufacturers have developed paint systems which are made to work together to protect the wood substrate. These systems include primers and appropriate, compatible top coats which can vary depending on the substrate and can vary between manufacturers. As a result appropriate primers and compatible top coats, both from the same manufacturer should be used.
There are three widely used coating systems which are applied to wood, i.e. a system with water based Acrylic or a system based on solvent or water based Polyurethane.
A. Water based Acrylic
The main advantage of water based Acrylic is that it contains low VOC's (volatile organic compounds), see below (*). They are ideal primers and have excellent adhesion. The low drying time is a major advantage. Water based finishes, in theory, are a more durable product than oil based coatings because it acts like a hard protective shell of plastic coating, sitting on top of the surface of the wood like paint. Because it goes down like paint, the applicant tends to have a greater reflection and shine; oil based finishes have a more natural apearance in comparison.
B. Oil (solvent) based Polyurethane
Short life is a major disadvantage of Polyurethane products. Polyurethane has hydroscopic tendencies, i.e. water absorption characteristics. The durability of polyurethane paints is adversely affected when exposed to direct sunlight or organic solvents. Polyurethane emits odors and fumes, though they're not that highly noticeable. The petroleum-based chemicals and flame retardant fumes may cause physical problems and may become irritating. Prolonged exposure to this smell may make people ill. Woodworkers who use Polyurethane finish also encounter overwhelming fumes. Some blowing agents in Polyurethane produce greenhouse gases that have negative effects on the atmosphere and adversely affect the environment. Though it is not as toxic as many other chemicals, it still harms the environment. Solvent based Polyurethane will cloud with age, as such tends to yellow
C. Water based Polyurethane
In contrast to oil based Polyuretahne paints, water-borne Polyurethane wood finish is non-toxic, and the fumes that it produces are safe to breathe. The excellent impact resistance and longevity of makes it suitable for floors, although the plastic-like appearance of a Polyurethane coating might detract from the appearance of certain varieties of wood, especially dense exotic hardwoods such as Teak, Mahagany, Bangkirai, Merbau. Unlike thje oil-based Polyurethane, a water based Polyurethane coat will not cloud and will remain clear
Based on the above we have chosen for the use of Acrylic rather than an oil based coating for a number of good reasons.
|1.||It dries quickly|
|2.||Despite the fact that acrylic paints can be diluted in water it is highly resistant to water once it has dried|
|3.||It emits very low VOC's (*), thus ECO friendly|
|4.||The paint is highly elastic, able to expand and contract without splitting|
|5.||The paint has excellent color retention and possesses better resistance to sunlight and the elements than oil-based paint|
|6.||Provide better resistance to mildew because thereis no oil in the paint. The oil of oil/alkyd paints acts as food for mildew|
|7.||Excellent protection (washability)|
|8.||Good water resistance|
|9.||Excellent adhesion to top coats|
|10.||Decreased odor, toxicity and flammability (due to lack of organic solvents and thinners)|
|11.||Excellent color and gloss retention|
|12.||Resist cracking and blistering better|
|13.||Resistance to alkali cleaners|
(*) Volatile organic compounds which have a high vapor pressure at normal room temperature. I it is toxic and long-term exposure to VOCs in the indoor environment can contribute to sick building syndrome. Health effects include eye, nose, and throat irritation, headaches, loss of coordination, nausea, damage to liver, kidney, and central nervous system. Dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. VOC's are found in oil based coatings (enamels, Alkyd) and some acrylic paints. The type of Acrylic that we use emits very low VOC's, hence safe for the painters at work
D. Oil treatment