Hello,
This morning while resawing White Pine boards, The smoke detectors started going off in my basement workshop! There was a blue haze in the air but as soon as I turned off my Bandsaw (Jet 18″ 18QT-3) and my dust collector (Delta 50-760) The smoke detectors stopped their alarm. The boards are 2″x6″x34″ and I had already resawn about 4 or 5 of these. I’m using a brand new Timber Wolf blade (3/4″, TPI-3, and .025 thick). Yesterday afternoon I emptied the delta, cleaned out the felt bag and vacuumed out the interior of the collector.
I could find no evidence that my blade was burning wood as it cut. The motor on the saw and the dust collector were both cool to the touch I cleaned out the interior of the saw cabinets and again there was no evidence of chared saw dust. But the saw dust was very fine almost like talc. I cleaned the saw and cleaned any pitch off the blade.
I started resawing again and half way through the second board I saw blue smoke coming out of the collector’s felt bag! I removed the bag and other than more very fine saw dust I could find no evidence of any chared sawdust??? The interior of the collector also had fine saw dust.
I wondering if somehow the dust is getting into the fan bearing and burning there. Do any of you have any experience with this or have some idea as to what is happening? I would appreciate any thoughts. Thanks. Bar Harbor Dave
Replies
Most likely, either your blade is dull or you are running out of line with it, did you adjust or check for drift? If you did several boards with no issues, it's the blade getting dull. If you are out of line, the back edge of the blade will be in friction. When you have heat build up it can smoke. The danger is that fire can start. Don't be connected to the collector until you find the problem. Heat will also help to dull the blade as will accumulation of gum, particularly with pine. On a bandsaw, you won't always see a burned edge or charred sawdust like with a circular saw. Carefully feel the blade for heat, it can get very hot. If it was the collector, it would smoke running by itself.
You should do a thorough check, blade tensioned, no little chunks or slivers stuck behind the wheels or under the throat plate, drive belt alignment and tension, free of debris. Make sure the blade alignment blocks and rear bearings aren't too tight against the blade and blocks are behind the gullets. Check the tires for indications of slipping blade. Check for blade drift when all is set up. If all is correct, you will know that it is the blade, if that's the only time you get smoke. At least you know your smoke alarms are working.
To Hammer1
Thank you for your very complete discription of items to check on my bandsaw. I mentioned that my blade is new, but I have resawn about 36 feet of the 6" pine. Would that be enough to dull it? It still feels sharp to the touch, but the fine saw dust could be an indication of a dull blade, like a dull chain saw. I have gone over everything else. the cut in the board is nice and straight with out deflection. When I stopped the saw the blade did not seem to hot. It is helpful to know that I won't necessarily find the charred sawdust with the band saw.
I will recheck everything on the saw and run the collector by itself to see if I get smoke coming out of it. If the blade is dull it seems like I didn't get much use out of it, unless It overheated and dulled as a result. In any case thank you for your response it was helpful to hear yout thoughts. Bar Harbor Dave
Good Call
Hammer, you were spot on it was a dull blade. I replaced the Timber Wolf with a Woodslicer and after tuning everything I no longer had the smoke and there was far less resistance from the blade. Thanks!
Resawing can be wicked tough on blades, Baah Habbaah, don'tcha know.
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