Here is a challenge to you. See if you know the answers. I will do a question and answer portion to this blog weekly if the comments are favorable. Let me know what other forestry related questions are important to you that need answers? Here is Quiz #1.
1. When is the best time of year to cut my trees for milling?
There are several factors that effect the timing of milling various species of trees. The final use of the product you have processed is a major consideration. Boards that have the final destination of being used in general construction such as 2×4′s and 2×6′s can be processed from typical soft wood species immediately upon felling of the tree. The only draw back from this would be the presence of sap in the log which unless handled well, with a good quality cutting lubricant will coat your blades and cause blade drag . This will not allow the saw dust to exit the cut efficiently which can result in very poor and slow cutting.
The blade lubricants that are most common are a mixture of water and soap. Dish soap in water mixed to the point that when you rub the water between your fingers you can feel the lubrication. Actual mix will vary with hardness of water and or type of dish soap. The best guide is the finger test.
I have also found that mixing about a cup of the cleaning solvent (Pinesol) in 2 gallons of this mixture will help dramatically in breaking down the sap and cleaning the blade.
Most trees in early spring will have an abundance of sap so if sap is excessive allowing the logs to sit for approximately 3 months will reduce the sap issue.
Winter felling of trees produces a cleaner product and a tree that is normally dormant so the sap issue is reduced.
Sawing of frozen logs has never created any problems for me and in some cases I find frozen wood in some species easier to cut.
2. What is a board foot / what is a cord of wood/ what is a comparable cubic measure?
Lumber is measured in different ways based on industry standards that date back many years. Novice mill owners are always concerned that when they see or hear people talk about lumber they use terms like board feet and cords of wood. They are normally confused even more when they go to there local lumber yard and but a 2×4 and measure it and find out it is actually 1.”5.5″ x3.5″. And even some times a little less.
The terms like 2×4 and 2×6 for example are terms that ave been established as the rough sawn dimension of the material. The store bought product has been dried and planned which has reduced its size. The rough sawn dimension has remained the industry standard for reference of these products. On the other hand a 4×8 sheet of plywood for example will be 4×8 as it says. Mainly because it is a manufactured product not a natural product.
- Board Foot – This term is used to measure lumber. It is a measure of volume and is based on the rough sawn dimension of the product. The actual measure is based on a surface area of 1 square inch X 1″ thick and that is a board foot. Example a piece of lumber 1″ thick X 12″ square is 1 board foot. A piece of lumber 2′ long X 6″ wide is 1 board foot and a piece of lumber 3′ long x 4″ wide is 1 board foot. If you do the math the actual volume of each of these is the same.
- Cord – This term is usually used in the scaling of logs and or fuel wood. This is also a measure of volume. The actual cord is based on a pile of wood. 4′ high x 4′ deep by 8′ long or 128 cubic feet. This term will be used when selling or buying logs. When associated with fuel-wood that has been processed the actual cord reference is used but may in fact mean a face cord. The face cord is based on a volume of material that is 4′ high x 8′ long and by varying depths. The fuel-wood is sold in various lengths such as 16″ long or 12″ long or even now very popular 24″ long for the out door furnaces. The volume of material you will receive will vary according to length so it is important to qualify the actual dimensions of your face cord when purchasing or selling as to the length of the material. You could be be quoted on a 12″ face cord as opposed to a 24″ face cord and feel the 12″ is a great price but in fact you are getting less material.
- Cubic Measure – This is a term that normally which usually reduces the confusion in volume it is the actual cubic measure of the pile of logs or even lumber you are buying or selling.
3. How long does an average band saw blade last?
This is one of the hardest questions I am asked to answer at shows or during demonstrations that will be atrue representation of the facts. This is because the life of the blade is dependent on so many variables. Manufacturer of blade, type of blade guiding system, type of wood being processed and cleanliness of material being processed all are huge factors in blade life. The typical band saw blade should be able to be sharpened at least 6-8 times and may need to be re set after every 2nd or third sharpening.
What I use as a rule of thumb is approximately 1-1/2 to 2 hours of actually producing saw dust with the blade between sharpenings. This does not include indexing of logs and set up time for each cut, just the time saw dust is being produced. Blades will general produce in the range of 12 – 16 hours of cutting and based on the quality and value of your logs that are being processed this factors in to a very low expense for the end products produced.
4. Can I use the lumber I mill immediately or do I need to dry it first?
The short answer is yes with the following observations.
- Pine and Spruce – Sap issues will effect the joy in cutting these products at various times of the year. See above comments on blade lubrication. Proper air drying if not nailed in place quickly to control warp age , cupping and staining must be observed.
- Hemlock and Tamarack – Excellent product to saw and a great looking product used a lot in horse stables and fencing due to its resistance to rot and horses seem to dislike the taste so they do not normally chew the hemlock. The down side is unless you are willing to drill each screw or nail hole you need to get it in place while it is still wet or when it has dried it becomes very hard and brittle and makes nailing very difficult if not impossible.
- Cedar - When using rough sawn wood for construction as above or for example Cedar for siding and deck flooring it is very important if the lumber has not been allowed to air dry for a few months to securely nail or screw it in place. When I use fresh sawen cedar for deck flooring in say 5 quarter thickness I install the boards tight together. In a few months there is rarely a gap between boards of more than 3/32″ which makes for a very effective and attractive deck floor. I have seen very little change in the length.
- Hardwoods – Hardwoods used for furniture can be processed immediately as well although final use will be only after sufficient drying methods have been used to dry the material. This will allow stress relief in the lumber and to reach a final moisture level ready for use in an indoor controlled environment.
Various ways of drying can be used. Kilns can achieve this drying level in less than 30 days but does add extra expence. Air drying in a covered enviriorment with excellent air flow will achieve acceptable levels for most hardwoods in 9 months to a year.
It is of utmost importance that when air drying that the boards be stacked flat and straight with air gaps between each board of at least 1/4″ and air gaps between each level of boards of at least 3/4″ with air flow available from end to end and around the out side of the stack. I suggest the use of stickers which will be boards of approximately 3/4″ by 1″ in dimension of the same material you are drying be used to create the space between each level of boards. Stickers should be spaced no more than three feet apart and within 18″ from the end of the boards.
If your lumber has been air dried and you will be using it in a controlled environment I suggest storing the air dried lumber in side the area it will be used for at least 30 days before assembling. This will allow the lumber to reach the actual levels of moisture that is normal for the area. Lumber will take on moisture equal to its surroundings for as long as it is exposed to it.
In short based on your application and final use of the product you can saw lumber as soon as you wish after falling the tree. Your successful use of the product will be based on your handling of the lumber from your mill. Have fun.
