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Pine is the most widespread material in the European woodworking industry. Even though it is easy enough to saw and to process, we would like to share with you some experience collected by thousands of owners of Wood-Mizer sawmills during the last twenty years.
What sawing scheme to choose
The first cut is one of the most important in order to maximize the production of material and profit from the log. The operator should be knowledgeable of the main product categories and their values that can be got from the log in order to determine the correct cutting pattern for maximum recovery. Some say that this means that you have to develop a "sixth sense" or x-ray vision so that you can determine what is actually in a log before you start to cut.
Assuming that the sawyer knows his business, he still needs to receive logs that have been properly felled, cross-cut and sorted. Logs should be as straight as possible and should not have large butts, dirty bark, and large knots. The sawyer is not a magician. If the logs have been properly prepared he can maximize the return from each log.
In order to maximize production the sawyer and the edger operator must work together as a team so that they can balance production between the saws and thus optimize production and quality recovery. The decision of which cutting pattern to use depends on many things such as the products required, the quality of the log, its size, taper and also the type of production line that you have.
In general terms there are three main cutting patterns;
1. Grade Sawing. This generally involves assessing the grade of each board as it is cut and the likely grade of the next board. Often you will make one or maybe two cuts and then turn the log by ninety degrees and repeat the process until you reach the heart, which is then blocked. This will maximize the recovery of high grade boards from the outside of a log, but does involve a lot of turning and log handling. The Wood-Mizer hydraulic mills make this type of operation as cost effective as possible.
2. Through and through Sawing. The log is aligned ( normally with the heart centered) and then one or two cuts are made to create one flat face. The log is then turned by 180° and the sawyer then simply keeps cutting down through the log at the required thickness. This is a fast production method as long as you have an edger working with you to edge the boards, but in Pine, this takes no account of grade material and will yield low levels of grade material. This method in Pine is normally only recommended for low grade logs where productivity is important.
3. Dimensional Sawing. In this case the operator is normally cutting the finished dimensioned timber out of the log and usually involves "taking the square out of the log" centered round the heart and getting as many side boards as possible. The center block (square or rectangular) may then be sawn on the primary breakdown saw into its elements or maybe passed on down the line to a resaw, or may simply be sold as a square. This method of sawing is often used with average quality logs for the mass production of standard dimensions for the construction industry.
How to solve the problem of pitch
Many beginners, the first time they see the Wood-Mizer sawmill at work, ask: "Why do you pour water onto the blade while sawing"? The water is used to clean the blade of the pitch that would otherwise stick to the blade. The Wood-Mizer "Lube-Mizer" system lubricates both sides of the blade with easily controlled amounts of water.
As is well known, pine often has a lot of pitch. If you saw at temperatures below freezing you should use anti-freeze ni the water to prevent freezing. The addition of simple washing up liquid also helps in the removal of pitch from the blade. In no circumstances should you use diesel fuel to lubricate the blade since this corrodes the special belts used on the pulley wheels. If the logs are completely frozen there is no need to use any form of lubricant.
How to prepare your blades
Usually for working with pine the most popular standard Wood-Mizer blades are used. These have a width of 32 mm and a thickness of 1,06 mm. They are produced from the factory with our 13/30 profile and a standard tooth height of 6 mm. The set is normally 0.023.of an inch.
If you use the Wood-Mizer sharpener with the borazon grinding wheel, the wheel has the correct profile for the Wood-Mizer blade.
In frozen Pine logs, it is necessary to saw them as if they were hardwood species. In this case the so-called "winter" Wood-Mizer blades have proved to be very effective. These have a width of 32 mm, thickness of 1,14 mm and they have a shorter tooth with a lower hook angle. The 9/29 profile. The set is normally about 0.019 of an inch.
How to prevent wood turning blue
Usually the blue discoloration is considered to be an aesthetic defect. Among woodworkers it is often believed that bluestain does not adversely affect the strength properties of the wood. But it is not so. Bluestain reduces both the impact resistance and the module of elasticity of the timber. In addition to this the absorption of treatment chemicals is impaired.
There are both physical and chemical methods in the struggle against bluestain. Physical methods consist of either keeping the timber very wet, or at the opposite extreme, drying the timber as quickly as possible. Storing wood in water or its irrigation with water prevents bluestain but is a temporary solution.There is another danger - anaerobic bacteria.They perforate the wood fibers and walls that eventually results in the saturation of the log entirely and renders it useless.
Reduction of wood humidity can occur during natural drying or in a dryer. Natural or atmospheric drying is a slow process where the most important factors are to store the wood "open-stacked" and in a well ventilated location so that the timber will dry as fast as if the stacked wood has not already been infected and the wood can dry to below about 20% humidity then the wood will not turn blue.
Combating bluestain s not such a simple thing as it may seem. Many owners of sawmills say that the client will not pay for additional chemical processing of the wood. In other words, the price of treated timber is no different from the price of untreated timber. There is no incentive for the manufacturer to install a treatment plant.However, think of the loss incurred if you allow your timber to become blue. At best, its value will be decreased at worst you will not be able to sell it at all. You must make every effort in your production process and storage of your valuable Pine timber to protect against this degradation.
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