Thread: 3 quick quick questions about my dust set up.

I can't answer the third question.

If you block off one side to use one bag your airflow will suffer because you are reducing the surface area the air flows through. Adding more bags would improve the flow, just not practical. You could get special order bigger bags if you have the height in the room. Don't reduce the filters.

The escaping dust is from the fabric not being a tight enough weave, folds or rucks as Bob calls them, under the clamps of the filter and plastic collection bags, leaks in various joints, bolt holes and if you reuse the plastic bags, holes in them from small bits of wood and handling. You can go over the machine and seal the leaks with sealant on the gaskets etc. Basically every spot with little plumes of dust showing and that will help. If by pleated bags you are referring to cartridge filters they will improve the airflow because of the larger surface area and they seal better. You still need two.

Best thing to do is to have it outside in it's own attached shed. Then you wouldn't have to do anything to the machine. I notice in your pictures you are using 4"/100mm hose. They don't allow much more that 400CFM (cubic feet per minute) of airflow through them. If you went to 6"/150mm and opened the machines to accept it your airflow would go up to 1,200CFM and capture a lot more dust.

If none of the above are palatable, wearing a cartridge mask and ventilating the shop until the air has cleared up is the easy option. Lots in the forum's past posts about it.

Pete

Those plastic gates to fit 100 mm ducting are junk mainly because they fit inside the 100 mm ducting and end up having a 94mm ID which further restricts air flow. 100mm down to 94 mm may not seem like much but given 100 mm ducting produces a very ordinary airflow its only going further backwards.

The way around this is to look for gates that fit over the ducting but its probably easier to make your own.

If you don't like wearing masks like me it is possible to deal with escaping fine using added forced ventilation air extraction fans.

That all makes sense and I thank you both for your replies.
I understand now that going down to one bag on that DC would be counter productive, disappointing as that is.
For most DIY people, dust collection efficiency is an evolving thing. My first stab at it was okay, but I see where it can be improved initially- 6 inch rigid pipe and better gates are the easy fixes. I have had a few sessions sealing up leaks on the DC, but that's an ongoing thing. It's amazing how that dust finds its way out under pressure.
Putting the machine outside is not an option in the dense urban area where I live, but I had another thought today. What if I made a structure against the wall that encapsulated the whole machine and put an exhaust fan where the vent is on the wall behind it that to vent the machine to the outside?

Originally Posted by scottbr

Putting the machine outside is not an option in the dense urban area where I live,

My house is on 1/8th of an acre block 2.5km from the centre of Perth. I've had my DC outside for 12 years. It's inside a noise reducing enclosure outside my shed which makes the sound of my DC at the fussy neighbour's fence line quieter than his pool pump which runs a lot more often than my DC. Occasionally some dust does leak from the DC but all the visible stuff drops out inside enclosure.

but I had another thought today. What if I made a structure against the wall that encapsulated the whole machine and put an exhaust fan where the vent is on the wall behind it that to vent the machine to the outside?

same idea as above but
- this consumes valuable shed space
- noise remains with you inside the shed.
- If the DC is outside the shed no fan is needed.

Originally Posted by scottbr

Putting the machine outside is not an option in the dense urban area where I live, but I had another thought today. What if I made a structure against the wall that encapsulated the whole machine and put an exhaust fan where the vent is on the wall behind it that to vent the machine to the outside?

If you are willing to sacrifice the space, enclosing the DC and venting out will work. You will want to soundproof the enclosure and the vent will need to be baffled to cut the noise leaving. There are a number of threads throughout the forum showing just that. The Sticky Bob put together shows how the internals of the muffler/baffled exhaust should be configured. The exhaust opening is best if it is 2 to 3 times the area of the inlet so it isn't restricting the air leaving. That's covered in the Sticky and a number of places in the forum.

Pete

Thanks again Bob and thanks Pete.
I have just read the sticky on enclosures.
I read a lot of stuff here on dust before setting up my shed, but it's something you sort of have to do and then fiddle with - that's how my mind works, at least.
Down the track I might bite the bullet and move the DC outside, but the only place it can go is about 4 metres from a bedroom window - neighbour - and I tend to do most of my stuff after hours.
In the meantime, I'll make incremental changes to what I have and see how it goes.

That old 3hp machine seems pretty good, so I'm loathe to get rid of it. I would like one that has just a single bag, though. That's really all I need. There are a lot of DCs out there, though, so it's hard to know what single bag units might have the pulling power of my one.

Scott

Originally Posted by scottbr

Thanks again Bob and thanks Pete.
I have just read the sticky on enclosures.
I read a lot of stuff here on dust before setting up my shed, but it's something you sort of have to do and then fiddle with - that's how my mind works, at least.

I think that's the case for most DIY'ers.

That old 3hp machine seems pretty good, so I'm loathe to get rid of it. I would like one that has just a single bag, though. That's really all I need. There are a lot of DCs out there, though, so it's hard to know what single bag units might have the pulling power of my one.

If you want a smaller foot print then a cyclone is one way to do it.
BUT.
Depending on what machines you are using bear in mind that at least in for the first 20-30L of collected sawdust Cyclones will usually rob more flow than filters. Also unless it is a Bill Pentze type cyclone the robbed floe will be very significant and leaves more fine dust behind at the source/machine. So to be effective a larger machine than you currently have will be need to get adequate performance.
You could keep using what you have (ie single bag), increase the ducting and machine port sizes to get more flow, and add ventilation.

Thanks Bob.
I'll make those incremental improvements over the next month or so.
Need to find some 6 inch gates for a reasonable price.

left field Q
due to renting a shed with 1 access door and 1 large sliding door and no windows and no way to create cross ventilation without industrial fans etc and not happy about leaving gear outside and prefering not to have dust collection inside......
Could I build a stand alone enclosed dust 'box' with 2HP dusty inside, insulated/soundproofed ertc and when wanting to use it wheel it outside plug in ilug in a piece of 150mm flexi hose to the fixed pipework inside the shed

Originally Posted by Tonyz

left field Q
due to renting a shed with 1 access door and 1 large sliding door and no windows and no way to create cross ventilation without industrial fans etc and not happy about leaving gear outside and prefering not to have dust collection inside......
Could I build a stand alone enclosed dust 'box' with 2HP dusty inside, insulated/soundproofed ertc and when wanting to use it wheel it outside plug in ilug in a piece of 150mm flexi hose to the fixed pipework inside the shed

Sounds like the sort of thing I would try, Tony. Worth a shot, I reckon, though as evidenced by this thread my dust control knowledge is pretty low.