The Thien Separator Inside A Craftsman Wet Dry Vac

[Kelly Bellis]

Experiment #1, Test 1

Not sure exactly what caused my first trial to pretty much utterly fail. I suspect that the hand plane shavings should never have been included while vacuuming the mess up off of my shop floor which has been building up since when I first started work on this endeavor, having the vacuum in various dissembled states. Still, maximum sized chips needed to be tested. These were normal size shavings from a 2" cutting iron that created a major clog and was part of this experimental first running of the Thien Separator that I designed to fit into my 32-year old shop vac - Sears Model No. 113.178081, should you care about such details. More details are shown in the attached drawings and photos.

Placing the completed Thien Separator assembly into the 16-gallon plastic barrel and aligning the vacuum head with its integral intake port and the 2" PVC fitting required some attention, but fit perfectly. By studying the dust pattern around this connection, there is evidence that the seal between the PVC fitting and the molded plastic lid was good. Likewise the weather stripping seals on both the top and bottom of the 9" x 2" filter did their job. Also, the filter did its job as it was quite packed with dust in the creases of the filter's paper folds. Soundly rapping the filter against the inside of the barrel loosened most of the debris but not all of it; I'll need to find somebody that has an air compressor and try blowing the rest of it out before Experiment #1, Test2.

[retired2]

If the schematic is an accurate representation or your build, then it is pretty obvious why you had a major failure.  If the inlet elbow sits against or even close to the baffle, the shavings will quickly pile up behind that elbow and cause a clog.  The photo of your "major" clog tends to confirm that assessment, there is a pile of shavings clogged up behind the elbow.  There needs to be space between that elbow and the separator floor (baffle) to allow shavings to circulate until they are removed by the drop slot.

[Kelly Bellis]

There needs to be space between that elbow and the separator floor (baffle) to allow shavings to circulate until they are removed by the drop slot.

@retired2
Not sure if Phil is AWOL, but I'll just let his photos offer another opinion

[retired2]

Your design will work with smaller waste but not planer shavings.  Your not the first person to discover this problem, it has been discussed more than once.

[Kelly Bellis]

Experiment #1, Test 2

By overtly not including shavings from my Millers Falls 14B hand plane (similar to a Stanley No. 5), and only vacuuming the debris beneath the table saw, Test 2 results were much more encouraging. Principally made up of wood fibers, the sawdust also includes a little bit of chips from PVC pipe and sheet. There were no clogs; however, an appreciable number of fines did escape the baffle and get trapped by the filter above the baffle. What remains to be seen is using this as a normal shop vacuum and under the present configuration of Experiment #1: how frequently the filter will need to be cleaned. Oh and by the way, those hand plane shavings also bollixed up the original, pre-Thien Separator vacuum setup  ;)

[retired2]

What many people have done to avoid rebuilding their separator is just take a slice off the bottom of the elbow.  Run it through your band saw if you?ve got one.  Start with a small slice and keep increasing it till it works.

Oh, another thing I think is troublesome are the spoked ribs under your baffle. The air under the baffle should spin smoothly.  The spokes create turbulence that could adversely effect the performance of the drop slot.

[Kelly Bellis]

Hi retired2,
Thank you for your suggestions. Could you post a photo of what the underside of your baffle looks like without disturbing the dust patterns?

I'm not absolutely sure, but it doesn't look like Phil needed to slice off the bottom of the PVC fitting as it appears to be in full contact with the bottom of the baffle:


Experiment #1, Test 2 results did not indicate there to be anything fetched up at the bottom of the PVC fitting, just a little dangling from the edge of the drop slot. See photo

[retired2]

http://www.jpthien.com/smf/index.php?topic=563.0

You are too focused on the photo of Phil?s early separator.  People don?t typically build shop vac separators for planer applications.  Attached to a planer, Phil?s separator would clog just like yours.  Top hat designs were developed because they solve remove the  inlet pipe from the waste stream.  I?m sure Phil would be giving you the same advice I have. 

[Kelly Bellis]

http://www.jpthien.com/smf/index.php?topic=563.0

Thanks for the link to that thread which I have read in its entirety already; however, I don't recall a single image of the bottom of your separator showing any dust patterns.

[Kelly Bellis]

You are too focused on the photo of Phil?s early separator.  People don?t typically build shop vac separators for planer applications.  Attached to a planer, Phil?s separator would clog just like yours.  Top hat designs were developed because they solve remove the  inlet pipe from the waste stream.  I?m sure Phil would be giving you the same advice I have.

Who said I had a planer? I don't own one yet, though if I ever do, the Dewalt DW735 sounds like the way to go.

Here's two of the hand planes that I frequently use since earlier this winter:

[retired2]

I thought you asked for a photo of the underside of my baffle?  That photo is in the first group of construction photos in the link I sent you.

The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference.  In fact, the shavings from a hand plane are probably worse.

[Kelly Bellis]

I thought you asked for a photo of the underside of my baffle?

Sorry, I wasn't clear. I'm curious about the dust patterns on the underside of the baffle after it's been in use, not prior. I am interested in seeing what they look like on your top hat version.

[Kelly Bellis]

The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference.  In fact, the shavings from a hand plane are probably worse.

Agreed. I just wasn't seriously planning on hooking up an intake hose connected to my Stanley No. 4 hand plane; however, that said, I must confess of staging something akin to that as a cartoon of sorts! LOL  ;D

[Kelly Bellis]

Experiment #1, Test 3
This test centered in particular on mitigation of turbulence beneath the baffle by covering the support brackets in shrink wrap film. And to much delight, the impact was most noticeable.

One sidebar note, the baffle fits extremely well in the barrel making its removal a little tricky, so much so, that the birch drawer pulls that were originally screwed onto the threaded rods finally just could not hold their threads. Thus, the new metal knobs which had to be re-drilled and tapped to accommodate the #10-24 rods. Works quite well!

[Kelly Bellis]

Top hat designs were developed because they solve remove the  inlet pipe from the waste stream.

Yes, I get that, and look forward to one day possibly trying to make such a version of the Thien Separator, and with many thanks to yours, and others, work on them.

My original intent was to see if I could, albeit in this crude fashion, introduce this concept of particle separation wholly contained within a regular shop vac. I'm still puzzled greatly by the fact that none of the shop vac manufacturers have not made, at least to my knowledge, a shop vac that incorporates a Thien style separator, or some other means of cyclonic separation. I've written to Dyson, but from their response, gave the impression that they weren't interested in the wood workers' niche, nor in the development of a small self contained vacuum system designed for the small wood working shop. Imagine a highly efficient and powerful Dyson hanging off the back of your bandsaw, or neatly tucked behind your lathe, table saw, etc. The need for elaborate and expensive dust collection systems with pipes and hose run everywhere, up one side and down the other, could all be eliminated. This is what I liked about Hector's neat and modest custom setup under his table saw.