dust collection for TS

Silvan <[email protected]> wrote:

> 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 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.
--
To email me use: sjusenet AT comcast DOT net

Silvan wrote:

> 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?

Yeah, I thought not.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/

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

Silvan wrote:

> 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.

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

Steve James wrote:

> 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

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. <sigh>

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/

Silvan wrote:

> 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.

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

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.
--
Larry C in Auburn, WA

"Silvan" <[email protected]> wrote in message
news:[email protected]...
> 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.
>
> --
> Michael McIntyre ---- Silvan <[email protected]>
> Linux fanatic, and certified Geek; registered Linux user #243621
> http://www.geocities.com/Paris/Rue/5407/
>

Larry C in Auburn, WA wrote:

> escaping. If you put a light behind the vac you should be able to see if
> any fine dust is escaping.

Good idea...

> 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.

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.

> 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.

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.

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

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.

> Hope this helps a little.

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.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/

Clarke Echols wrote:

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.

--
Michael McIntyre ---- Silvan <[email protected]>
Linux fanatic, and certified Geek; registered Linux user #243621
http://www.geocities.com/Paris/Rue/5407/