I have a Delta 20″ band saw which is my workhorse machine. I’m using a shop-vac attached to the machine for dust extraction and that works great much of the time, but deep resawing operations (particularly 8″ or more) and certain woods create clouds of ultrafine dust. Several things occurred to me:
1. get a finer filter for the shop vac. They make a HEPA filter for it
2. Reduce bade tooth count for deep cuts. I’m using a 4 TPI blade most of the time, but I’ll bet a 3 will work better.
3. get an air cleaner, though I recognize that it’s not really going to make the air appreciably more healthy while the saw is running
Other ideas?
Pete
Replies
Item 1 will only work if all the dust is getting to the vacuum. So, is it? Do you see dust leaving the saw at various places? If dust is leaving the saw, other than through the vac, then it seems to me you'll need to add another vac port.
If all the dust is getting to the vac, are you using a bag in the vac? I use a bag, a cloth bag over the filter, and the filter itself and I don't see any dust out of the vac.
A lot of it is getting to the vacuum. I haven't figured out yet whether a significant amount is getting out above the table. Only a small percentage of the heavy dust is getting by, mostly when the blade first hits the wood. I have a bag. What's in the air looks like smoke. What I'd like to do is reduce the creation of these fines in the first place.What got me thinking about this was my slicing up a couple of 10" slabs of spalted maple that were punky on the edges. My lungs are still feeling it 12 hr later. Definitely don't want to do that again.Pete
Dust is BAD stuff, that was a major contributor to my grandfather's early demise :-(
http://home.comcast.net/~ed.harrow/shop_and_tools1.htm This will show you my set up. It handles 4" stuff OK, but I can't speak as to whether it would handle your resawing. You may need to add a second port (did I already mention that?)
"What got me thinking about this was my slicing up a couple of 10" slabs of spalted maple that were punky on the edges. My lungs are still feeling it 12 hr later. " Oh Pete, please be careful with the spalted wood! Wear your respirator when working it, then leave the building with the air filter running. Nasty, nasty stuff.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Yeah, I know that now. Doesn't cut like regular wood at all.Pete
Pete,
I believe FG was referring to the possibility of inhaling the organisms responsible for the spalting.
Rich
Pete,
I think you will find a 3 TPI blade better than a 4 TPI for that resawing. I would even go to a 2 TPI if you can find it. In resawing, a lower tooth pitch is important for sawdust clearing in the kerf and will result in a smoother cut and better routing of the sawdust down into the lower chamber where it can be drawn into the DC system, rather than escape above the table. It's possible that you are seeing smoke as you're cutting!
It's surprising that a shop vac is giving you satisfactory results. I recommend at least a 1-1/2 HP dedicated dust collector. Such a unit can give much better collection out the bandsaw's DC port due to higher airflow (suction) and allow a secondary hose positioned either right under the front of the table where a lot of bandsaws spew dust or above the table.
Rich
Thanks for the information. I'll definitely go to a 2 or 3 TPI.
It's not smoke, luckily. Just talc-like dust. Some gets left behind in the cut.
The dust colletion on this machine is very well designed, with good airflow right under the insert and excellent airflow across the blade as it passes the dust port. Truly a case of "they don't make 'em like they used to". A second port at the edge of the table would help though when I get a real dust collector.
Pete
Have you installed brushes on the tires and for the blade? Especially on the bottom. I lined the blade guard where the blade enters from the bottom wheel with the fuzzy side of adhesive backed velcro. Seems to help. If you're working in an open space use a box fan to suck any escaping dust away from you.John O'Connell - JKO Handcrafted Woodworking
The more things change ...
We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.
Petronious Arbiter, 210 BC
Until you find a better solution, wear a dust mask
Yeah, I can do that, but I'd need to wear my respirator, as the typical dust mask won't catch many of the fines.
Thanks to all for the suggestions. I've ordered a HEPA filter for the shop vac, as I think it's currently distributing rather than catching the fines. I'll run a coarser blade for resawing too. For really nasty cutting jobs I'll go with the respirator.
Pete
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