Thien Separator round one

[smallboat]

After reading Joe's helpful post from last November I took the plunge and built a Thien baffle yesterday.
http://www.ncwoodworker.net/forums/f81-workshops/thien-baffle-notes-41627.html?highlight=thien
I have to say I wasn't real impressed when I first switched on the shop vac.
I mean it worked, but not as well as I had hoped.
Then I decided to tape up the holes in the worn out plastic trash barrel I had fit it to.
I also covered the center hole in the baffle ( pivot from when I cut it)

WOW!
All the visible dust is in the barrel not the vac.
I'll have to keep an eye on the filter and see if the small stuff accumulates there.

Of course it grabbed my pants leg and promptly collapsed the barrel.
Guess I'll need to find a real barrel for round two.

Joe - thanks for your post, especially the photo showing the relationship between the inlet and the chip slot.
I was "baffled" there for a while.

BTW- where did you find those 45 deg flanged connectors. I didn't see them at the BORG.

Steve

 

[Joe Scharle]

Woodcraft has them:
[h=1]2-1/2" Router Fence Dust Extraction Fitting $5.95[/h]
Item #85O13

 

[DWSmith]

Woodcraft has them:
2-1/2" Router Fence Dust Extraction Fitting $5.95


Item #85O13

Part # at Woodcraft shows up a router bit.

 

[Joe Scharle]

Can't explain Woodcraft.....I did a simple cut/paste!

 

[manfre]

Woodcraft part link

 

[Dudelive]

Buy 2-1 2 Router Fence Dust Extraction Fitting at Woodcraft

Did a copy and paste from Joe's post and found the above

 

[smallboat]

Thanks everyone. That clears it up.
I tried the link and got the router bit
Then I tried using the search on the Woodcraft site and got the same.

I might have to use these on my upgrade.

New question-
Does it help performance to have to path from the vac to the separator as short and smooth as possible? (assuming you have a robust barrel)
Logic would say yes, but my logic doesn't always agree with reality.
Of course having the extra flex hose in there allows me more reach when I'm trying to clean up across the shop.

 

[MarkE]

Ethan and/or Alan can explain this better than me, but my rule of thumb is, shorter is more efficient than longer. That being said, I have a 25' hose attached to my shop vac for cleaning up the floors, and it does a very good job.

I am not currently using a Thien separator. My shop vac is pulling through a Clear Vue CV06 mini cyclone. Same principal, different design.

I was using a Thien on my last DC, a 4 bag, 3hp, pulling through 4" hose. The Thien was mounted on a Rubbermaid 45 gallon Brute trash can. I would empty the trash can 5-6 times before getting more than a couple of inches in the DC plastic bags.

 

[DWSmith]

I am considering installing a dust hood on my two saws and the baffle sounds like a good idea. If I ever get caught up so I can devote some time to this I will make one to see how it will work.

 

[ehpoole]

New question-
Does it help performance to have to path from the vac to the separator as short and smooth as possible? (assuming you have a robust barrel)
Logic would say yes, but my logic doesn't always agree with reality.
Of course having the extra flex hose in there allows me more reach when I'm trying to clean up across the shop.

The general rule of thumb for laminar airflow is actually some multiple (that I do not recall) of the pipe/hose diameter should be a straight shot before and after turns. For 1-1/2" to 2-1/2" a couple feet would be adequate. That said, typical corrugated hose (the kind most commonly used on shop vacs) is not the ideal hose/piping for laminar airflow -- the smoother the walls the better.

When using long hoses with your shop vac, it is generally best to maintain the hose at 2-1/2 (or 2-1/4") for as long as possible before you step down to the smaller hose. This will keep the static pressure losses as low as practical for the length of run. If you have a choice, a step down reducer with a funnel/conical shape is preferred.

 

[ehpoole]

Of course it grabbed my pants leg and promptly collapsed the barrel.
Guess I'll need to find a real barrel for round two.

Even my 2HP Cyclone will collapse a Rubbermaid Brute trashcan. By comparison, shop vacs generate considerably higher static pressures (vacuum) than a Dust Collector -- just at lower air volumes.

To protect against collapse in the event that the intake becomes restricted for any reason, you are either going to have to use something really heavy-duty like a heavy steel drum OR you can use 1/8"x3/4" extruded aluminum bars (available at the BORG and elsewhere) to create hoops that you insert at regular intervals (or wherever there exists a weak point) in the trashcan. The hoops are much harder to collapse and help to stop the deformation before it can become irreversible.

Use 1/8" aluminum rivets to secure the ends of the extruded bars to form a rigid hoop. Then use 1/8" aluminum rivets at regular intervals (a half dozen around the perimeter is adequate) to rigidly secure the hoops to the trashcan (don't skip this step). To determine the length of the bar you will need, measure the diameter of the trashcan at the point where you want to install the hoop(s) and remember the formula that Circumference = Diameter X 3.14, then add a few extra inches for overlap so that you can rivet the two ends together to form the hoop. Whatever the extra length (say 3") make sure you mark that on one end of the aluminum bar so that you can butt the opposite end up to that line to wind up with a hoop that is the correct diameter. Then force the hoop into your trashcan pushing it down just a little further than it wants to go of its own accord so that it is exerting outward pressure against the walls.

The following photo shows the single hoop that was required to reinforce my Rubbermaid Brute for my 2HP Cyclone. As I said, a shop vac will require considerably more reinforcement due to the higher vacuum they develop. The actual hoop is visible just above the sawdust line. The rest of the visible aluminum is aluminum HVAC tape used for static dissipation (swirling sawdust can generate a lot of static -- enough to make you jump if you touch any exposed metal!).

 

[bluedawg76]

+1 to ethan's comments regarding the metal hoops. After collapsing my metal can after the first major clog, I installed 1 hoop about half way down and have not had any issues since.

Sam

 

[Dust Storm]

How about the fiberboard drum that Joe used? Does anyone have a local source for one of those?

 

[Joe Scharle]

Sometimes, the State Surplus yard will have a bunch of drums for bid. Register on the site and you can see what's available and make a bid. And if you have the space, you might want an old mechanical device just for the bearings, gears etc.!

 

[junquecol]

How about the fiberboard drum that Joe used? Does anyone have a local source for one of those?

Lowes, along with others get floor sweeping compound in them. Bakeries get yeast & baking powder in them. Call a janitorial supply company, and ask if they have empty drums for sale. They may do bulk into drums under a "house brand." Or they could tell you who they sell product in fiber drums to. I often see them as paper recycle bins in offices. Wurth (aka, Raleigh Hardwoods) gets sweeping compound in them.

 

[KenOfCary]

Although not as cheap as some of the suggested sources, I got one from these folks. They shipped it free and it was here in about 2 days via FedEx. About $50 for a 30 gallon drum with locking top.

Fiber Drums with Lever-Lock Tops : Drums, Drum Handling and Accessories : IndustrialSupplies.com

- Ken.

 

[smallboat]

Does the airflow below the baffle still need to circulate or is it more stationary?
If it's stationary I thought I could build a "birdcage" frame to reinforce the barrel.
A few vertical ribs with a couple of horizontal rings to hold them in position.
Make it removable for emptying purposes.

If the air needs to continue swirling, that would all get in the way.

Guess I'll need to stop at the BORG for some aluminum for the hoop solution.

 

[bluedawg76]

based on the design, i would assume that the material that falls below the baffle is out of the airstream and is thus no longer swirling. So any obstructions below the baffle should not be a hindrance. that said, seeing is believing, and mine doesn't have a window...hmmm...now there's an idea!

Sam

 

[joekwon80]

junquecol, did you ever find any leads on those fiber drums? I've been looking on surplus sites and found nc waste traders had a company in Sanford as giving them away. I called them up and they didn't know what I was talking about.

 

[smallboat]

Still looking for a good barrel.
I see plastic barrels on CL, sold as rain barrels.
Does anyone know if they are sturdier than the Rubbermaid trash barrel?

As for reinforcing the plastic trash barrel - I followed Ethan's advice and went the Aluminum band route.
It was quick and easy and not too $.

I've also realigned the intake with respect to the baffle slot.
The elbow is now over the end of the slot and the intake feeds onto the beginning of the closed section.
I had noticed that junk was accumulating behind the elbow, now it falls into the bottom.

To answer my own question from a couple weeks ago-
If my set up is any indication there is still a swirling airflow in the lower section.
I can see it in the way the small and large parts accumulate.
good thing I didn't build the "birdcage"