newbie questions

[hoover]

First off Phil - you're awesome.  (Thank you for making the planet a less dusty place).

I've tried to read as much as possible but still find myself with questions...

My application would be a 'mini - Thein' for field jobs that require short duration hand tool DC and general floor debris pick up.

What is consensus on squeezing Thein design into 5 gal bucket regarding pipe inlet / outlet diameter if I am using a Shop Vac designed for a 2 inch hose?
Seem to hear conflicting issues - 1) a smaller bucket diameter makes debris spin a bit fast,  & -  2) large inlet /outlet diameters for smaller diameter bucket reduces performance as well.  - 3) But using smaller diameter pipe will also increase air velocity? (was thinking of using 1-1/2 inch inlet / outlet).
Any advantages to adding a mini blast gate near / before the inlet to solve some of these issues? (meaning a valve I open to induct additional air not available in hose).
I also use a pre filter (dustless technologies) bag in my shop vac (but don't have to) would this perhaps changed the resistance enough to better accommodate a 1-1/2" inlet / outlet?

Would using any type of grounding strip for the HDPE bucket or the HPDE buckets metal handle be enough to dissipate static that interferes with performance or could I use an aluminum plate for Thien baffle and ground it through the all-thread bolts out the top of the lid.  Or would just grounding the 3 all thread bolts be enough without using an aluminum plate for the baffle? ( grounded to Shop Vac ground wire from it's supply cord ).

Is 1/8" 'tempered hardboard' the same thing as 'exterior grade masonite' ? 

In a small system like this is there enough of a performance advantage in placing the inlet on the side of bucket (tangent) vs an inlet elbow adjacent to center outlet through the lid? (the added work is not an issue for me - and no, I would not be using any duct tape.)

If the 1-1/2" pipe downsize from 2" is ok are there any advantages where you place the reducer near?  I read something here about 'chimneys' and assumed they were talking about straightening out the air flow (?). Does a taller outlet line above the lid actually help or is it due to some other effect since any straightening is after the fact.

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A 'd.deputy' option is no option for me at all:  too tall / top heavy, it's exposed and will eventually be damaged from abuse / rough service or parts flying around in the work van / and worst of all it's a possible conversation starter - anything I can do to keep clients from making small talk while I'm trying to work is high on my list.
An advantage to leveraging a mini Thein baffle with Shop Vac besides being a very portable & robust solution is that now I can use the volume inside the Shop Vac for permanent hose / accessories storage and access them with only the slight inconvenience of a low layer of fine dust.  Another plus for using any small separator on the job site is that you often inadvertently vacuum up a small tool / part / screw that you need.  Avoiding tearing open your only $10 poly pre-filter bag to retrieve the piece is worth the effort to make one right there.  (btw this system is not intended for my pre '78 RRP work).

[phil (admin)]

First off Phil - you're awesome.  (Thank you for making the planet a less dusty place).

I've tried to read as much as possible but still find myself with questions...

My application would be a 'mini - Thein' for field jobs that require short duration hand tool DC and general floor debris pick up.

What is consensus on squeezing Thein design into 5 gal bucket regarding pipe inlet / outlet diameter if I am using a Shop Vac designed for a 2 inch hose?


Not sure if there is a consensus.  Things to keep in mind:  As the diameter of the bucket gets smaller, the velocity of the spinning air mass with debris increases.  Normally greater velocity increases separation, but it also increases resistance.  You will reach a point where separation only increases marginally, but the resistance increases fantastically.  I've not used an actual 5-gallon bucket, but I've used vessels as small as one.  They work, but I think this is the lower-limit for 2-1/2" hose.


Seem to hear conflicting issues - 1) a smaller bucket diameter makes debris spin a bit fast,  & -  2) large inlet /outlet diameters for smaller diameter bucket reduces performance as well.  - 3) But using smaller diameter pipe will also increase air velocity? (was thinking of using 1-1/2 inch inlet / outlet).


Well it will increase the velocity INSIDE the hose, but not INSIDE the separator.  Inside the separator, the reduction in the amount of air will actually mean a decrease in velocity.  You will still have plenty for separation, but a 2-1/2" hose may outperform.


Any advantages to adding a mini blast gate near / before the inlet to solve some of these issues? (meaning a valve I open to induct additional air not available in hose).


Not a bad idea for experimentation, but I suspect you wouldn't really need it and it may get in the way.


I also use a pre filter (dustless technologies) bag in my shop vac (but don't have to) would this perhaps changed the resistance enough to better accommodate a 1-1/2" inlet / outlet?

Would using any type of grounding strip for the HDPE bucket or the HPDE buckets metal handle be enough to dissipate static that interferes with performance or could I use an aluminum plate for Thien baffle and ground it through the all-thread bolts out the top of the lid.  Or would just grounding the 3 all thread bolts be enough without using an aluminum plate for the baffle? ( grounded to Shop Vac ground wire from it's supply cord ).


When it comes to plastic drums, static is hit/miss.  Some of them seem to build static charges more than others, I think it has a lot to do with the type of plastic employed.  I use a 30-gallon plastic drum that seems to have fewer problems with static than (for example) the PVC fittings I use.



Is 1/8" 'tempered hardboard' the same thing as 'exterior grade masonite' ?


Probably close enough.  The stuff I use I get at a small lumber yard that also has a cabinet shop.  It is smooth both sides, and I think is normally used as a panel for cabinets that will get painted.


In a small system like this is there enough of a performance advantage in placing the inlet on the side of bucket (tangent) vs an inlet elbow adjacent to center outlet through the lid? (the added work is not an issue for me - and no, I would not be using any duct tape.)


Tangential inlets should always be better than a top inlet.  I still use a top inlet, it works well for my application.  But I'd use tangential if I could.



If the 1-1/2" pipe downsize from 2" is ok are there any advantages where you place the reducer near?  I read something here about 'chimneys' and assumed they were talking about straightening out the air flow (?). Does a taller outlet line above the lid actually help or is it due to some other effect since any straightening is after the fact.


A chimney is what I call an outlet pipe added to the DC ring where someone is adding a baffle.  Some rings absolutely need them, some can get by but would probably benefit from adding one.


-------------------------------------------------------- 

A 'd.deputy' option is no option for me at all:  too tall / top heavy, it's exposed and will eventually be damaged from abuse / rough service or parts flying around in the work van / and worst of all it's a possible conversation starter - anything I can do to keep clients from making small talk while I'm trying to work is high on my list.
An advantage to leveraging a mini Thein baffle with Shop Vac besides being a very portable & robust solution is that now I can use the volume inside the Shop Vac for permanent hose / accessories storage and access them with only the slight inconvenience of a low layer of fine dust.  Another plus for using any small separator on the job site is that you often inadvertently vacuum up a small tool / part / screw that you need.  Avoiding tearing open your only $10 poly pre-filter bag to retrieve the piece is worth the effort to make one right there.  (btw this system is not intended for my pre '78 RRP work).



Forgot to mention above, but I still like using a bag in the vac.  Some stuff makes it past, no matter what separator you use.  The bag prevents the filter from slow loading.