dust collection for TS

I'm setting up a shop vac/trash can cyclone poor man's DC, because I have to have something, and this is affordable, fits my space, and will hopefully be much better than nothing. I'm putting some faith in Lee Valley not to talk it up in the catalog. It really sounds like it will be quite satisfactory for my tiny shop, and all it takes is a few hoses and collection points. The trash can and shop vac already have permanent homes.

So that leads me to my point. The #1 priority is to get DC on the table saw. I don't care about the mountain of sawdust on the floor. What I want to cure, or at least severely curb, is the rooster tail blowing in my face, and the resultant airborn dust. I realize that the stuff I can see and feel isn't even my real problem.

So that brings up two issues. The first is collection itself. I have a stand-mounted benchtop saw. I've seen a few different takes on the same idea for this. Basically a sloped plywood box with the port at the bottom. That seems to me like it would get the stuff "off the floor" but it seems unlikely that the low CFM of a shop vac would be able to move enough air through such a large space to cure the rooster tail. Seems to me that I need a small enclosure that gets the port as close to the bottom of the table slot as practicable. No zero-clearance insert for this saw either (it's all but impossible to fit one, and involves reshaping the casting) so I have a pretty big gap there.

The gap strikes me as a potential problem, but I've spent many hours futzing with solutions if only for the sake of safety, and I've never come up with anything at all durable. I use my crosscut sled for thin cuts, even rips. Let's just take it for granted that it's a problem with no solution, and work around it. So, probably a bit less than 10" long, 1/4" gap on one side, 1/2" gap on the other, call it 7.5 sq. in. of air space around the blade. Given that much of a hole, is there *anything* can do in the way of rigging up a collection port that will be able to generate enough air movement to kill the rooster tail? I'm envisioning some kind of box that's just barely big enough to surround the blade, and which would prevent it from ever tilting again. (I don't need to be able to tilt it. I *do* need to make sure it continues to go up and down.) Seems such a box would be smaller than the usual tapered plywood solution, but still a rather large volume, with a rather large hole in the end. Is that just a lost cause?

The second issue is filtration. I have a HEPA filter on the shop vac now, and no visible dust blows out the exhaust. The stuff I need to worry about is invisible. How will I know if it's working? Since the thing doesn't need to be mobile, would it increase my success at protecting myself from microscopic dust if I locate the vac outside, under some kind of weatherproof lean-to, and run the hose through the wall? I would prefer to avoid having to do this if I can, because it would be a bitch to mow around, a bitch to ensure that it remains sufficiently weatherproof, and would demand some kind of remote switch. (Perhaps the latter is easy though. Ordinary wall switch, dedicated outlet on the other side of the wall... That's not unrealistic, and my shop is small enough that I can walk two steps from anywhere to anywhere. I don't really need a remote.)

So, anyway, these can't be new problems. I *have* been googling, but I would like some input from today's Wreck.

I'll also ask... Let's say this *is* hopless. I *have* to cure this dust problem sooner or later. I don't want to get emphyzema, and I already work in trailers filled with cardboard dust all day.

A cabinet saw is simply out of the question, but what about dust collection on contractor's or other benchtop type saws? Is it always a matter of rigging up some improv thing? Is there any saw built in such a fashion as to allow a reasonable chance of success with this sort of shop vac/cyclone system?

I might pop for a new table saw, max $500, with my share of the tax refund, and this might be the motivation I need to convince SWMBO that it's more important than, well, whatever else she might come up with. Putting that $500 in a real DC is another way to go too, I guess, but they're big, and I'd need more power, and anyway, I'd rather have a better table saw, because I've raised the bar as high as I can with this one, and it isn't high enough by a long shot. The only good thing about this saw is that it only cost me $50.

Reply to
Silvan
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If you're that tight on money, get a GOOD respirator with a HEPA filter in it, and forget the dust "collector". If it has a bag filter as in most smaller/cheaper collectors, all you're getting is a machine that scatters fine dust everywhere. You'll get less dust all over the place if you do nothing. Another alternative is to run a duct outside from the smaller "cyclone" DC. At least that gets rid of the fine dust somewhat. It's beyond me why some have the guts to call a plastic lid on a trash can a "cyclone", but there is no standard definition, so I suppose one could equally well call it a rocket-propelled grenade (half-smiley here).

And just because it looks like a cyclone doesn't mean it performs well. A good cyclone system is going to cost $1000 or more, but that's cheaper than a lot of household vacuums (Kirby, Interstate Engineering, Rainbow, etc.). One could consider making the case for using a good cyclone as a central vacuum for the rest of the house.

If money's a problem, you might consider an additional income source to make some extra cash to buy it with. It's interesting to note how few people seem to consider that as an option.

My experience over the last 40+ years is that money invested in quality tools is nearly always well-spent. I hate the tools I bought "on the cheap". And I know all about tight budgets. We raised nine kids on an engineer's modest paycheck, but we built a 8000 square-foot home through it all too. It wasn't easy.

CE

Reply to
Clarke Echols

Seal up the holes & give it a try. I did this with my Delta bench saw & Grizzly contractor saw and the Craftsman shop vac gets most of the dust.

Don't try to seal 100%. There has to be air flow into the saw and into the shop vac.

-- Mark

Reply to
Mark Jerde

An engineer's "modest" paycheck? If you really made/make less money than I do as an engineer, you wasted a lot of time in school.

You get a touché on the get a second job thing, but I'm not that desperate.

60-80 hours a week is plenty. Whatever I need money for I can do without more easily than I can spend even more time working. Life's too short.

Note that I'm not asking to get anything for free, and I'm not expecting adjectives like "optimum, "ideal," or even "good" to apply to my cheap solution. I'll be happy if I can attain "barely adequate."

"Only cry once," sure, and I don't like my cheap tools either. But I *have* my cheap tools. I use them all the time, make beautiful things with them, and I have *time* to use them. That's my priority, and my prerogative.

So, now that you know that the parameters of this little experiment are not subject to change, do you have anything useful to suggest with respect to solving the problem as originally stated? Namely, devising the most effective dust pickup possible for this saw and this shop vac, no matter how comparatively ineffective it is.

Reply to
Silvan

I can't answer all your concerns, but I can tell you when I first hooked up a shop vac with a plastic can "cyclone" lid to a garbage can it really did capture a lot of stuff. All that made it to the vac was the fine stuff. The HEPA filter seems to work pretty well as I also never saw any fine dust escaping. If you put a light behind the vac you should be able to see if any fine dust is escaping.

You need to have some way for the vac to suck air so not having a zero clearance blade might not be a big issue if the saw is sealed elsewhere. I suppose it might even help because as the vac draws air through the insert opening it might capture much of the roostertail. I've actually tried to use tape for a zero clearance insert and I can't say it worked perfectly, but you could try it to reduce the insert opening for dust collection.

Putting your vac outside probably isn't a good solution as you want to minimize your ducting, I think especially with a shop vac.

Hope this helps a little.

Reply to
Larry C in Auburn, WA

Good idea...

Now that I've gone out in the snow to actually look at the thing, sealing it up tight is going to be pretty difficult anyway. The motor is bigger than I thought too.

So I'm thinking plywood on the bottom 2/3 of the way across, then plywood at

90 degrees to that fixed to the first and to the bottom of the table. That leaves the motor vent holes, the blade tilt hole, the insert hole as pretty much un-sealable.

I'm thinking to put the port on the side of the L, but maybe putting it on the bottom would be better. Let's try some quality ASCII art. Use a fixed-pitch font...

[][][][][][][][][][][][ B ][][][][][][][][][][][][][] || B | || || MMMMMMMMMMMMMMMMMMM B = || MMMMMMMMMMMMMMMMMMM B -S- || || MMMMMMMMMMMMMMMMMMM B = || MMMMMMMMMMMMMMMMMMMMB | || || MMMMMMMMMMMMMMMMMMM B | || MMMMMMMMMMMMMMMMMMM B | || || MMMMMMMMMMMMMMMMMMM B = || || B -Q- || || B = || ||===================| |=====+ || || -R- || || ||

The motor (M) actually moves a lot more than this drawing shows, and the box needs to be taller, with a lot more dead space than this, but this shows the general idea I'm talking about.

I'm wondering if a port at Q, R or S would be most effective.

Tried it. Never use duct tape for this. The goo on the *outside* of the tape is a big problem. Maybe airlane tape would have done better.

Not too big a concern though, because putting it outside might actually get it closer to the saw. I'm not looking at a big amount of ducting anyway.

If nothing else you've made me feel better that I'm not thinking a $1500 Pow-R-Sucko 2000XL is the only adequate solution here.

Reply to
Silvan

My Delta bench saw had an open bottom and a stand. I made a box about a foot tall, open at the top, that fit the opening. I cut a hole in the bottom a little larger than the shop vac hose size. I put three strips of wood around the hole that would hold the 6" nozzle, and I could slide that in and out. The box was held in place with a couple "L brackets" screwed to the box. The brackets just rested on the stand, they weren't screwed to the saw or stand.

This worked pretty well.

-- Mark

Reply to
Mark Jerde

Silvan wrote:

I have a Bosch 4000 benchtop table saw and am not yet ready to invest in a real DC (i.e. a true cyclone) although I probably will when I add more power tools. Right now I buy raw hardwood lumber and get it jointed and planed at the lumberyard because their tools are better than anything I can afford and they don't charge much for their shop time. Still, I would like to eventually have a planar and jointer at home because wood often changes dimensions a little once it has equilibrated to my shop. But for now here is my solution:

I bought the fixed stand that Bosch sells. I cut a piece of MDF to fit the top of the stand and cut out an insert in the center and installed a plastic 12" by 12" dust collector "hood" that Delta sells. Mounted this way it slopes down toward the center which has a fitting for 4" flexible hose. This particular saw has a shroud around the blade connected to a

2 1/2" dust port in the back for connection to a Shop Vac. I put a 2 1/2" to 4" adaptor on this dust port, then I connected the bottom 4" port and the dust shroud port to a Y fitting using a minimum of 4" flexible tubing. The third arm of the Y connects to my shop vac with a very short piece of 4" flexible tubing (adpator at the end of the tubing to take the 4" to 2 1/2" for the Shop Vac. The Shop Vac is a 6.5 "peak horsepower" QSP model with a large stainless steel tank. I put a Gore Cleanstream HEPA filter in it. I covered the two large openings on the saw (front and back) that are there for tilting the blade and motor using pieces of tempered hardboard that is taped on. That way I can remove them easily on the rare occasions when I want to tilt the blade. This still leaves plenty of openings for air flow (slots along the bottom of the saw base, the vents next to the motor, etc).

This set up works pretty well although there are a lot of reasons that it shouldn't. I used 4" tubing because I expect to eventually connect it to a real DC. One concern was that the air velocity would be too low to keep the dust suspended in 4" duct. After using the saw for a while I disconnected the tubing to take a look and found that there was no dust settling in the 4" tubing. There is coarse sawdust that settles inside on the MDF at the base of the saw. I simply vacuum it out occasionally by removing the insert and using my shop vac with a long thin attachment. The Shop Vac collects lots of fine dust and after a while the flow decreased noticably due to caking on the HEPA filter. Since cleaning this regularly is a pain and exposes you to lots of very fine dust, I decided to install a disposable drywall dust bag in the Shop Vac in addition to the HEPA filter. Now the drywall bag catches a lot of the fine dust and only the really small stuff makes it to the HEPA filter. It is easier to remove the disposable bag without exposing yourself to lots of fine dust, and now the HEPA filter doesn't need frequent cleaning. The reduction in air flow I got with this arrangement is much less than what occured as dust caked up on the HEPA filter. Plus every time you change the disposble bag you have fresh filter surface area so the flow should never get really bad. I always use the blade guard on my saw except when cutting with a dado blade. The dust shroud/ blade guard combo on this saw seem to be very well designed to catch the dust that would normally be thrown up into the air from the blade.

I look on this setup as an interim measure and one that I am comfortable with as long as my time in the shop is pretty limited. I always wear a Dustfoe 88 mask when using my table saw and will probably continue to do so even after buying a real DC because it is virtually impossible to get

100% dust collection from table saws.

$500 will not buy you a DC that will protect your health unless you believe that the new Jet cartridge type DC's are adequate. They spec them as "2 micron" but won't tell you what fraction of particles they capture at 2 microns (or any other size). I know because I've asked them. Quality cartridge filters are speced with much more detailed info than "captures down to 2 microns". Until someone independently evaluates their cartridges or Jet provides real specs I would be worried that they these units are pushing the particles that can do the most damage to your lungs back into the air. Another concern with the Jet is how frequently the expensive cartridges need to be changed. Since they don't have a cyclone to remove the majority of the particles, they cake up with dust rapidly and you remove that dust by turning a flapper that flexes the cartridge folds. What does that frequent mechanical flexing do to the performance of the cartridge and its lifetime? If the cartridges have to be changed frequently they will be more expensive in the long run than a real cyclone DC. I applaud Jet's innovation but they need to prove that their new units get rid of the really dangerous particle sizes before I would buy one.

Reply to
Steve James

Yeah, that's a good point. I should look into one of those bags. All that fine dust on my filter is one thing that has finally convinced me to do something about this. That dust is coming from when I vacuum the floor, after it has already had its trip through the air a few times until it settles out. I really need to at least curb that.

I guess I really should buy one of those stupid looking biohazard hoods too. Instead of a new table saw.

Reply to
Silvan
  1. Unless you capture the dust from the blade gueard during ripping operations, you are wasting your time. Way mmore than half the dust goes up into the air before the blade gullets can pull them down. So rig some kind of hose and a deflector to pull that into the shop vac.

  1. Don't plug up the holes, you have to have the air move to allow a vacuum to pull it--it needs something to pull.

  2. You won't capture much from below unless you have some kind of capture device/hood for the dust to go to. But it will pick uyp something.

  1. You will still get a lot of ambient dust, the fine stuff sadly. So you still need a good respirator. A ligth but good one is the DustFoe from Highland Hardware. Also an air cleaner system. They are a few hundred bucks tops, and they all do a great job of filtering out a lot of small dust particles.

My one claim to fame was maybe 10 years ago. FWW quoted me by saing, "Dust collection is a philosophy." I'll updat it by saying dust collectionis a software problem, not a hardware one. You not only need the equipment, you have to be willing to use it, every single time.

Reply to
DarylRos

not with my saw.

no guards at all. no dust collection other than the cabinet itself.

the cabinet fills up with sawdust. I occasionally get a little sawdust over the top of a board, and a little bit of the fines make it into the air. if I make a cut that is less than 1 kerf from the outboard edge I get a shower of sawdust over the saw top. for general cutting probably 99% or better goes down into the cabinet

if way more than half of the dust was going up into the air I'd know it....

that said, I still do intend to get dust collection to the tablesaw. Bridger

Reply to
nospam

I disagree! I have a Delta contractors saw. I built a "hopper" that fits the bottem, which gets hooked to my el-cheapo Harbor Frieght 2 HP, (Sears HP), dust collector. I covered the back of the saw with some cardboard untill I reach a better solution. My guess is 90% of the dust gets to the collector as there is very little left on the table. Even before the dust collector the majority of the dust went under the saw. Greg

Reply to
Greg O

Yeah, I thought not.

Reply to
Silvan

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