Originally Posted by
Charles Randal Smith
It is a bit like comparing apples and oranges. They both give you flat lumber, but do so with markedly different costs and efficiencies.
If you have only an occasional tree to mill, then a chainsaw mill is a great solution. It may not give a thickness of cut that is quite as consistent or may not yield as good a surface as with a bandsaw mill, but it is nevertheless quite acceptable. And with experience, these issues become negligible.
From your example, I am not certain if you are referencing a log 26 inches in diameter or one with a circumference of 26 inches, which would be about 8 ¼ inches in diameter.
The length of time it takes to mill a log is, of course, dependent on the number of cuts you are going to take (i.e., the board thickness), the length and diameter of the log, and the type of wood, among other factors. With a chainsaw mill, you may go through 1 or 2 feet of log length a minute for smaller logs, and up to several minutes per foot for massive logs. Remember that the length of time to take a cut with a bandsaw mill or a chainsaw mill is only a part of the overall amount of time it takes to mill a log. Setup time, moving the log, adjusting the mill, and stacking the boards are only some of the activities which also burn up time.
The biggest cost in a chainsaw mill is the powerhead (i.e., the chainsaw’s motor), if you do not already own one. You will need a good-sized powerhead if you are cutting a 26 inch diameter log. A small log (under 16 or 18 inches diameter) can be well handled by a powerhead of 50 or 60 ccs, give or take. A 26 inch diameter log needs a much larger chainsaw motor (think closer to 85 ccs). And when you get into the larger logs, this is a two-person operation.
When using a chainsaw mill with a rip chain, your kerf is ¼ inches, as compared to a bandsaw mill which typically has a 1/8 inch kerf. Hence, your waste is somewhat greater.
There is one situation wherein a chainsaw mill is clearly superior to a bandsaw mill (besides being a fraction of the cost of an entry-level bandsaw mill). Bandsaw mills have an upper limit of the width which they can cut. That is often in the range of 26 to 28 inches, which means the largest log you can possible mill on a bandsaw mill is an absolute maximum of 36 inches (which generates a cant about 26 inches square). However a chainsaw mill with a huge motor can handle a bar length of 48 or even 60 inches, thus allowing you to (slowly!) mill logs which are beyond the capacity of a more expensive bandsaw mill.
A second advantage to a chainsaw mill is that it can get into loci that are inaccessible to a bandsaw mill. For example, if you have a large log to be milled in someone’s back yard, removing an intact log from a fenced-in yard may be difficult or impossible because of limited access to the location. But you can carry a chainsaw mill into a back yard and come out with beautiful boards or slabs that one person (or perhaps two) can easily carry.
It is important to keep in mind that sometimes it is not a question of chainsaw versus bandsaw mill. Both are needed on occasion. Full disclosure: I have a Wood-Mizer bandsaw mill that cost a bit under $40,000, and for occasional use, I employ the Granberg Alaskan chainsaw mill with 48 inch bar that cost about 5% of the bandsaw mill. But for my next big log that is waiting to be milled (Black Walnut 15 feet long and 35-40 inches diameter) I need my chainsaw mill as it is too big for my Wood-Mizer.
Regardless of which way you go, you will discover the joy of opening a log and seeing incredibly beautiful grain patterns. A significant benefit of milling your own logs is that you have some control over how well the grain is shown.
Charles