Thread: ShopVac System or Dedicated DC

Some questions

How big is your shed?
What other ventilation/doors/windows etc do you have that you can keep open?
Are you in a position to put a DC outside or at least build a cupboard for it inside the shed but so that it vents outside the shed?

Originally Posted by BobL

Some questions

How big is your shed?
What other ventilation/doors/windows etc do you have that you can keep open?
Are you in a position to put a DC outside or at least build a cupboard for it inside the shed but so that it vents outside the shed?

Thanks BobL for your reply ...

Currently i am using the mobile bench (with sander, scrollsaw, drill press) in my 2 car garage, which has a double panel lift door at the front and on the back wall is a single roller door, large sliding window and access door.
I have on many occasions however wheeled the bench under my back patio which is open on 3 sides (as is much cooler in summer). It is outside that i also use the tablesaw/drop saw as required.

A DC could be positioned in free space under the patio at the rear - however looking for a small footprint solution that would handle these fine dust making machines.

Your situation is a very common one, but unfortunately there is no simple inexpensive answer.

With small machines and small 2" inlets I could say just get a shop vac and a dust deputy and you will have pretty good control of the visible dust but I note you specifically said you want to control fine dust.

To control fine dust from machines there is no substitute for high volume air flows and the minimum flow rates from even small machines is considered to be 800+ cfm.
The most a vacuum cleaner can draw is around 100 cfm
The most a 1HP DC can draw is around 350 CFM
The most a stock 2HP DC can draw is around 550 cfm
Unless you can go to a bigger DC or a modified 2HP DC (see https://www.woodworkforums.com/showth...ht=generic+2HP ) and use 6" ducting ! then you have to resign yourself to not fully controlling fine dust.
Each will work a little better up the scale and only you can determine what is satisfactory for you.

A second problem you have is that machinery with 2" outlets are on a hiding to nowhere because the most flow that can be dragged through a 2" opening by a DC or VC is around 60 to 100 cfm.
So either the machines have to be modified to take the 6" ducting
OR
you make up a surrounding cowling or open box for the machine and park the machine inside that and attach the 6" duct to that.
OR
You just park a 6" DC inlet as close as possible to the machine
The first of these options will be the most efficient for fine dust and chip collection through to the third being the least efficient.

All this sounds like total overkill but that is the perennial dilemma of WW dust control and why we rabbit on so much about this is this forum.

Originally Posted by BobL

All this sounds like total overkill but that is the perennial dilemma of WW dust control and why we rabbit on so much about this is this forum.

Thesmo,

Bob guided me through through my dust collection upgrade, and he knows what he is doing.

At first, I resisted going the whole hog at collecting the very fine dust. Eventually I drew up a wishlist. This included small footprint, ducted system (so I am not dragging machines around), the effective collection of very fine dust and so on. Making the decision was then easy ... not cheap, but easy. Each one of us must decide what his needs are, and what is "good enough" for fine dust collection. I recommend you make up such a wish list of essential and desirable features. If you do that, Bob can be more precise in his recommendations.

Have fun!

John

I'm in a very similar situation to the OP and have enjoyed (perhaps not the right word) reading this section of the forum and extracting/collecting information from BobL and others on the art and science. From being very close to buying a cheap shopvac and building a Thien Baffle I am now pondering more seriously how best to invest my time/money for the long term.

Without wanting to force BobL in to repeating himself in another "how to collect dust" post I'm hoping to ask a couple of questions in line with the OPs question:

- Even when a reasonable 2/3 HP DC solution is implemented w/ large ducting, does the shopvac still have a use for connection to small dust ports on handheld tools such as routers/sanders, via a baffle/seperator, and perhaps a large DC duct at the shopvac exhaust? Or is investment in a shopvac a complete waste if the end goal is to have a 2/3 HP DC?

- Like many here starting in WW, dust collection wasn't considered on the wishlist of tools (foolishly) and so it is now seen as an "unbudgeted" expense. From a value perspective do you consider it best to invest in a 2HP generic device such as the H&F DC3 or budget Carbetec and optimise it per your other threads, or shoot for the 3HP generic device such as the H&F DC7 which also has room for improvement but perhaps can move more air without modification than the 2HP?

Appreciate any comments and hope these questions aren't too repetitive - I have had a serious read of the other threads but may have missed it.
Thanks,
Liam.

Originally Posted by Binary01

- Even when a reasonable 2/3 HP DC solution is implemented w/ large ducting, does the shopvac still have a use for connection to small dust ports on handheld tools such as routers/sanders, via a baffle/seperator, and perhaps a large DC duct at the shopvac exhaust? Or is investment in a shopvac a complete waste if the end goal is to have a 2/3 HP DC?

Shopvacs located outside or kept stationary in a shed and vented fully outside (including the motor loop) can be very useful if connection to hand tools etc. They still don't capture as much of the fine dust in some situations as I would like which is why I prefer to use a DC on some power tools (such as sanders) over a shop vac. Like movable DCs most of the problems with vacs is that they get towed around inside a shed and get battered and then leak.

I have a blower vac that I use occasionally when I'm doing a job inside the house so I can dangle the outlet outside a window to keep the house cleaner. But this is not a long term solution for a shed. The motor cooling loop still generates a lot of fine dust so they need to be located or fully vented vented outside. Some recommended methods are described in this thread https://www.woodworkforums.com/f200/shop-vac-washable-filters-worth-181779

Like many here starting in WW, dust collection wasn't considered on the wishlist of tools (foolishly) and so it is now seen as an "unbudgeted" expense. From a value perspective do you consider it best to invest in a 2HP generic device such as the H&F DC3 or budget Carbetec and optimise it per your other threads, or shoot for the 3HP generic device such as the H&F DC7 which also has room for improvement but perhaps can move more air without modification than the 2HP

I would not recommend a stock 2HP generic type DC for any situation. When modified as per my https://www.woodworkforums.com/showth...ht=generic+2HP thread they are borderline even for a single car garage/shed and ducting lengths resulting that size shed. A two car garage really needs a 3HP and a 13" impeller and bigger than that, a 4HP with a 15" impeller.

Originally Posted by Binary01

Even when a reasonable 2/3 HP DC solution is implemented w/ large ducting, does the shopvac still have a use for connection to small dust ports on handheld tools such as routers/sanders, via a baffle/seperator, and perhaps a large DC duct at the shopvac exhaust? Or is investment in a shopvac a complete waste if the end goal is to have a 2/3 HP DC?

As Bob suggested, I found I needed both. My shop vac is outside under a hood with 50 mm PVC pipe connecting the vac to the flexy hose inside. Moving it outside is the best dust control measure I have implemented other than installing the cyclone and ducting. Vacs produce the worst kind of dust, the superfine stuff.

Originally Posted by Binary01

- Like many here starting in WW, dust collection wasn't considered on the wishlist of tools (foolishly) and so it is now seen as an "unbudgeted" expense. From a value perspective do you consider it best to invest in a 2HP generic device such as the H&F DC3 or budget Carbetec and optimise it per your other threads, or shoot for the 3HP generic device such as the H&F DC7 which also has room for improvement but perhaps can move more air without modification than the 2HP?

That's exactly my situation ... dust control was a very low priority when I started.

When we compare the figures for volume of air flow it is clear that an optimised 2 HP, whilst better than the standard beast, is not really suited to be connected up to ductwork. More properly, it should be hooked up to the machine with 6' or less of flexy. Even then, it has the potential for leaks, and if that happens you might soon have a shop full of fine dust.

The 3 HP machine has better airflow, but still one must be very careful with duct restrictions and especially with machine ports. At least with the 3 HP machine you can put up ductwork in a small to medium sized shop.

It really is a matter of what you see as value, including your health. If we opt for a 2 HP dusty, we really need to be prepared to drag the machine around the shop and to be careful with maintenance and machine checks (leaks ... blocked filters etc).

If we opt for a 3 HP machine, we have the same maintenance issues (blocked filters), but at least we get ducting and the opportunity to park the dusty outside so leaks won't hurt us.

So, it is a very individual decision. I found that writing down my wish list of essential and desirable features virtually made the decision for me. Only one solution combined small footprint, venting outside (no leak issues), no filters to block or clean, and a ducted system so I was not dragging machines around the shop. I did what was important for me. Unless we know what is important for you, further recommendation is pretty tough.

Cheerio!

John

Thank you for your feedback BobL and John - very much appreciated.

I guess like so many when i started WW over 6 months ago, dust collection and control was the furthest thing from my mind. Whilst working outside i never really noticed the dust issue, but having recently temporarily moved my bench into the garage it has become more noticeable (especially on the cars).

This led me to look at possible dust control solutions, and of course alerted me to the potential dangers with inhaling these finer particles over time. Having a young family, it is not only my health i need to look out for but also theirs - thus why i am looking to try and address this issue as best i can.

The main problem i have is - i don't have a spot where i can permanently setup my machines/benches within the garage and thus a dust collection unit. A small part of me was holding onto a glimmer of hope that i could incorporate a under bench shopvac system which would be portable with my bench - but now know that at best this would only be good for post WW cleanup.

Until I have a permanent place to setup i need my benches to remain mobile, and also a DC system to do the same. With a young family, budget is always an issue and i don't have a couple of thousand to throw at a solution right now. Perhaps a 2HP DC with upgraded filter might be a compromise for me at the moment in my current situation. This would give me reasonable airflow, allow the unit to move with the bench, and not break the bank.

I know this is not perfect - but would be a big step up from current solution of no collection!

Likewise, thanks Bob and John for your detailed responses.
At this stage I will keep saving for 3hp unit, given that the cost difference vs 2hp isn't that great, especially considering the work to modify the 2hp generic to obtain a borderline result.
I might also buy cheap shopvac and park it outside in the immediate term, but will otherwise plan how to commission a 3hp DC with final exhaust venting to outside.
More reading to do...

Originally Posted by thesmo

Until I have a permanent place to setup i need my benches to remain mobile, and also a DC system to do the same. With a young family, budget is always an issue and i don't have a couple of thousand to throw at a solution right now. Perhaps a 2HP DC with upgraded filter might be a compromise for me at the moment in my current situation. This would give me reasonable airflow, allow the unit to move with the bench, and not break the bank.

I know this is not perfect - but would be a big step up from current solution of no collection!

It sounds like a pretty good solution to me, given your circumstances. So long as you are mindful of the need to keep filters clean and are alert for leaks (which Bob tells us is often a big issue), you should do pretty well.

If you are going to optimise a 2 HP DC, it might be a good idea to start looking around for a decent second hand unit. It somehow makes more sense to me to perform surgery on a second hand rather than a brand new machine.

Cheerio!

John

Originally Posted by John Samuel

If you are going to optimise a 2 HP DC, it might be a good idea to start looking around for a decent second hand unit. It somehow makes more sense to me to perform surgery on a second hand rather than a brand new machine.

Yes - i am already on the hunt for one as we speak.

If others in are interested - I found a 2HP Carbatec Unit (almost 3Yrs old) with upgraded cartridge filter for $250 on eBay this morning (3 days left on Auction, no bids at the time) in SmithField NSW.
I thought good value for a unit which would retail for about $590 (inc upgraded filter).

Originally Posted by thesmo

Yes - i am already on the hunt for one as we speak.

If others in are interested - I found a 2HP Carbatec Unit (almost 3Yrs old) with upgraded cartridge filter for $250 on eBay this morning (3 days left on Auction, no bids at the time) in SmithField NSW.
I thought good value for a unit which would retail for about $590 (inc upgraded filter).

That is indeed a good deal.

Just a few tips tip about buying a used generic 2HP DC.

If you want to upgrade the unit according to my generic 2HP DC upgrade, make sure you get the unit that has the rectangular/square (nor round) cross section impeller outlet - the former is a bit easier to mate to the bag housing than the latter.

The motor and impeller are usually OK but obviously run them to make sure they do not vibrate too much which could be a sign for a damaged impeller.

If there is a problem with these units it will be with leaks. Around the impeller and the filter housing seal evidence of leaks can be cleaned up by the seller and these can be fixed anyway.

Leaks in pleated filter cartridges are not so easy to clean or fix. Usually these leaks will appear as darker than usual stains on the outside surface of the filter. Small leaks can be fixed using a dob of silicone but the cannot really be tested without using a particle counter.

So i took the plunge and bought a 2nd hand 2HP DC.

Until i can save some $$$ to implement suggested changes, I will move my work area out under the back patio to help with dust escape into the atmosphere.

Having looked over the 2HP Generic DC mod pages, I feel comfortable performing some of the easier mods (i.e changing the inlet) but the thought of modifying the outlet seems a little more difficult.

Is there an easy way to work out what dimensions are needed to make this new filter inlet?

Originally Posted by thesmo

So i took the plunge and bought a 2nd hand 2HP DC.

Is there an easy way to work out what dimensions are needed to make this new filter inlet?

I started by making a rectangular metal tube to connected the impeller to the bag housing.
The width and height of the tube are the same as the outlet stub that comes off the Impeller.
Then I put the round filter bag housing on top of the metal tube and traced and then cut out the curve with felt marker and a jigsaw.
Now hold the curved part up against the bag housing and stick a felt marker down inside the metal tube and mark out the hole on the filter housing
I cut the hole out with a thin kerf cut off wheel on an angle grinder.
Then I made up the flanges for each end of the tube. I welded mine on onto the tube but they could be made of galvanised sheet metal and pop riveted onto the tube
Then I clamped everything in place and drilled all the holes and bolted it together..
I used a rubber gasket to par seal the gaps but some silicone was needed for a proper seal.

I can't measure it up for you as that DC is back at the milling year and I'm not due to go over there for another week or so.

You don't have to use metal, Jonno used MDF for his