The Blade You Select DOES Matter
When you saw through stock that is very thick, every tooth will shave a ton of waste off of the board. To have a reasonable productive feed rate, you have to have somewhere for the waste to fall out of the way once the teeth emerge from the cuts. If not, the gullets that are between the teeth will end up filling up and stalling until the stock has been cleared.
Blades with about 3 teeth per inch (tpi) have large gullets which can accommodate as much waste as you’ll generate by sawing through thick stock, and they’ll handle anything less substantial with no trouble at all. The best choice is to use a thin kerf, 3-5 tooth per inch variable pitch blade. Try to get a decent one.
In theory, the wider the blade for you bandsaw, the higher that the beam strength is going to be and it will maintain a straighter cut. Once you get past a 1/2 blade it could actually worsen the cut. Most blades made in the US that are over 1/2″ wide are .035″ in thickness, and that is thicker than the Wood Slicer’s total kerf width. Blades that are 3/4″ are set up to give a coarser cut, so once you get that wide of a blade you are going backwards.
Don’t Worry Too Much About Higher Tension
The least important factor in resawing wood is the tension. Don’t overlook it though, it is still significant. Having the right blade tension will keep the stock centered. This is true even if the control isn’t absolutely flawless. But it will reduce the bandsaw blades means of fluttering while under the thrust. It isn’t difficult to set the tension correctly. What you do is install the wood slicer on the saw, and use the lateral guides and the thrust bearings will open up and back off above as well as below the table so that these don’t contact the blade. Go ahead and add the tension as you go, and give your blade a poke from the side about halfway between the wheels.
When it is at the right tension, the blade is going to deflect a short distance, and all of the sudden stop like it is hitting a wall. The harder you push the further it will bend, but the main thing is the sudden stop. Add enough tension until the movement of the blade sideways is around 1/4″ on saws that have a 6″ cutting depth. If it has a 12 inch cutting depth, then about 3/8″ movement. Don’t look at the tension gauge that is built into the saw until you are done. There isn’t any need to get confused by these arbitrary numbers. Once you have the hang of tensioning using touch, then you can check this gauge to see if it is accurate.
Once you have put the right amount of tension on the blade, and it is tracking correctly, then you need to tune it. This fine tuning will make all the difference in the cut. Before bringing the lateral guides as well as the thrust bearings close to your blade, make sure to close the doors to the wheels, then you can turn on the saw.
If there is so much vibration the blade blurs, try to increase or decrease the tension a hair bit at a time until the blade is running smooth and straight. The cuts will end up being smoother when the kerf has no fluttering, and the saw will also be quieter and cut better as well.
Part 2 of this post is going to be about controlling your stock, but also about one of the biggest mistakes that are made when resawing wood. This mistake causes an uneven cut. So stay tuned!