Thread: A not so nubie trying to catch up......?

I'm very sorry to hear about your situation which is precisely the kind of thing we are trying to avoid in this forum. Unfortunately 125mm systems are just not capable of sustaining the flow needed to deal with wood dust, especially on something like your big sander. 125mm is limited to a max of about 750 CFM which about 25% less than is necessary. 150 mm would be a minimum to deal with this and it will need to be matched to to a DC more powerful than a generic 2HP DC. The DC must also be outside the shed.

As well as an improved DC system i would strongly recommend a full face respirator to make sure the allergy is contained.

the elephant in your corner is that vacuum cleaner. I would get that outside the shed and duct internally with dedicated 50 mm ducting .

Thanks Bob,
I was a bit depressed last night that I may have wasted my money on what I had done to date BUT the first part of catching up is knowing where UP is!
Today I decided that success will be relative and I decided that I had been a 2 out of 10, that 150 mm ducting and new bigger DC would be 10 but that my current DC and 150 ducting could still get me to a 7.
I finished installing the new DC and a modification of the existing 100 mm ducting just to suit the new DC and went around cleaning up the gates and general leak proofing.
The change in efficiency is already impressive! I can only now imagine what a 10 would be like because this improvement to maybe a 4 is already very satisfying.
I still need to urgently sort out what to do about the portable power tools because the cheap-as-chips shop vacuum is now clearly a major contributor to the airborne dust and second only to the sanders!
I am planning/hoping on extending the shed this summer and will design it to isolate the DC from the internal space. I will also take the opportunity to relay out all of the equipment and install 150mm ducting.
Until then I will keep the 100/2HP arrangement, use the Microclene WHENEVER I am in the shed and use the respirator if sanding but particularly when using the 16/32 flat bed.
Thanks for the reply Bob and thanks for the concerned PM's.
Fletty

Hi Fletty,
Not good to be suffering from the effects of wood dust, good to see you on the road to doing something about it tho, plenty of reading/references on the forum with plenty of us who have been there/done that, BobL is the forum dust guru. No question is too silly, someone will most likely have an answer.

To setup a good system can be costly and ongoing but what price do we put on our health and noone is getting any younger!

There many simple things that will make life easy in the shed, as Bob has said getting the DC and vac outside is a big step, also plenty of forced ventillation, a fan on one side of the shed and another on the other side, or with your belt sander fans positioned so as to create a draft away from where you stand to operate the machine, if you know a sparky or air con guy you might be able to get hold of the fans out of redundant split system ac units, I got 4 of these fans from a local bloke, they are low power but still move good amounts of air.

Hope the wood dust issues settle down soon.

Cheers,


Pete

Hello Fletty,

I understand the situation. Did a dummy spit two years ago and did as close to a proper job on dust collection as I could. BobL was a constant and reliable guide, and others like PJT also made valuable contributions. The transformation in my shop was remarkable.

For now I will limit myself to one element, your vac.

Apart from installing a cyclone with 6" ducting the biggest improvement I made was putting the new 2 HP vac outside under a hood. I ran 50 mm PVC into the shop and ditched the filters (check the power draw without filters first). This achieved two things. First the dust capture from hand tools improved significantly (compared to the original el cheapo vac). Secondly, vacs can easily produce more fine dust than they capture. I deliberately did not clean around mine for about a month just to see what would happen. I built up a thick layer of superfine dust on the wall behind the vac. I tried to design an alternate solution, but in the end figured out that BobL was right ... again. The best solution is to get the vac outside.

Thanks John,
the advice from Bob, Pete and others has been invaluable. I spent much of Sunday cleaning the shed. The inside looked like a monochrome photo of various shades of red!
Stage 1 (new DC, clean-up and evicting the shop vac) is well under way and I have rewired the shop so that the Microclene comes on with the lights.
I will move the flatbed sander to beside the DC when I use it so that initially I can remove the losses from the long ducts but I am working out how to convert it to at least 125mm and have a short flexible from straight from the DC.
Stage 2 (125mm ducting, DC outside) will have to wait until I get some time off over Christmas. I don't want to annoy my neighbours so I am looking at a free standing acoustic block enclosure outside the shed for the DC.
The improvement is already amazing!

fletty

Good to hear you are making progress.

Originally Posted by fletty

Thanks John,
the advice from Bob, Pete and others has been invaluable. I spent much of Sunday cleaning the shed. The inside looked like a monochrome photo of various shades of red!
Stage 1 (new DC, clean-up and evicting the shop vac) is well under way and I have rewired the shop so that the Microclene comes on with the lights.
I will move the flatbed sander to beside the DC when I use it so that initially I can remove the losses from the long ducts but I am working out how to convert it to at least 125mm and have a short flexible from straight from the DC.
Stage 2 (125mm ducting, DC outside) will have to wait until I get some time off over Christmas. I don't want to annoy my neighbours so I am looking at a free standing acoustic block enclosure outside the shed for the DC.
The improvement is already amazing!

fletty

Fletty,

When I put in a ducted system Ronboult was kind enough to bring his clever instruments to the shop to make airflow measurements. The data were clear. The biggest losses came from the machines themselves, including their hoods/ports/shrouds. This is after I had spent a lot of time upgrading ports/shrouds. So, the big lesson is that whilst length of pipe and number/type of fittings are important, they remain secondary to the machines themselves.

Have fun!

Originally Posted by John Samuel

So, the big lesson is that whilst length of pipe and number/type of fittings are important, they remain secondary to the machines themselves.

Have fun!

I was wondering about that because I have gates on each of the flexible droppers which I USUALLY close when not using that line or machine but I reasoned that, if they are hard connected to a machine port, then I shouldn't need to close it ...but I certainly do!
A quick check showed that even a compact machine like the jointer has many unnecessary openings that must affect the efficiency of dust collection?
One further comment on the design/operation/maintenance of components is that, with the new DC connected to my dustright vacuum wand, I was marvelling at how fabulous it was at cleaning the floor ......only to realise that I had actually left its gate CLOSED!
You can imagine that it was EVEN BETTER when I opened the gate!
fletty

Originally Posted by fletty

A quick check showed that even a compact machine like the jointer has many unnecessary openings that must affect the efficiency of dust collection?
fletty

I have the opposite problem with my planer/thicknesser ... can't get enough air INTO the machine. It is the only machine not upgraded to 6" ports because there is no point unless and until I can find a way to get a lot more air into the machine. The very small openings around the cutters mean that the machine can't pass enough air to max out a 4" line, let alone a 6" line.

If it is of interest to you, here is the thread showing my journey to upgrade machine ports to 150 mm.
https://www.woodworkforums.com/showth...+upgrading+150

Wood dust collection from a source involves two components, Chips and visible dust which act like small pieces of solid material, and fine invisible dust which has some characteristics of a gas.

The most efficient collection of these two components is different and they can end up opposing the collection of each other.

Chip and visible dust require a high air speed (e.g. 4,000 ft/min, fpm) to be efficiently collected at source. A simple way to achieve this, especially from low powered VCs or DCs, is to constrict and direct the air flow into a narrow so the air passes at high speed across the source and sweeps away this dust. This is how vacuum cleaners work. This mode of collections suits high chip/low fine dust volume generators like drill presses. Unfortunately, raising the air speed to a point where it grabs chips reduces the total amount (volume) of air that flows past the collection point and this allows fine dust to be driven outside the range of the collecting air stream. A classic example of this is table saws which generate high speed air currents and spray fine dust all over a shed.

Efficient collection of fine invisible dust requires as much total air as possible (1000 cubic ft/min,cfm ) to be grabbed at the sources. To achieve this requires as little constriction around cabinets, blades and guards as possible. A major constrictor is often the wood being worked on itself. In an ideal scenario there would be nothing around the blade or workpiece allowing for the continual capture of a large bubble of air. A good example of nothing around the workpiece is on a lathe where only a turning chisel is usually involved. Unfortunately this can enable wood chips with a high momentum to escape outside the collection bubble and so wood work machinery manufactures add shrouds and cabinets which trap the chips but this blocks volume air flow reducing fine dust capture by the DC.

Remember the chips and visible dust are much less likely to affect you health wise than the finer dust. If visible chips do escape they can be swept into a pile and sucked up with a bit of flexy attached to a DC located outside.

So how does one get both air speed and volume flow. Unfortunately achieving 4,000 fpm AND 1000 cfm is only possible using a large DC. A 3HP, 150 mm ducting all the way to machines and as JS says the machines MUST be opened up to be able to utilise this collection ability.

Apart from lathes, I don't think I have ever seen a wood working machine that has sufficient openings on it.
Gaps or hole ~3 mm or less are so restrictive that can be ignored in any assessment of gaps around a machine.

Ideally the total area of gaps in a machine should be
- twice the area of the ducting cross section area
- located so they create an air flow across the dust generation point
- opposite to the duct port so the air flow is in the same general direction as the air flow generated by the machine cutting parts. This means if the cutting tool is spinning in a clockwise direction the air flow should not be in a counter clockwise direction.
The duct port should be of as low a resistive type as possible e.g. see https://www.woodworkforums.com/f200/improving-machine-cabinet-dust-ports-187936.
This is not always possible or easy but deliberately doing the opposite will make things worse and it may well pay to close off some gaps and open up more in more suitable places.

Being currently on a sabbatical from anything sharp, I've been doing a few light maintenance jobs in the shed. My new 'economy' 2HP dust collector has been in use for a few months and I've noticed number of significant leaks which are evidenced by a dust patch pointing accusatively at the leak site. Even though it will soon be moved outside, there is no reason to put up with these leaks. 2 of these leaks are on the disc that covers the impeller and contains the main entry to the impeller. I removed it only to find that the CaN (cheap and nasty) gasket had slipped during assembly and was not in place at the 2 leak points. I relocated it, glued it to the cover, smeared vaseline on the open face and reassembled. The leaks appear to be fixed and an annoying noise has also gone.
There are a further 2 leaks between the plastic bag and the body which I will also fix when I have 2 working hands but I'm thinking of gluing a rubber strip to the body so that the clamp has something to bite into.
As the impeller entry is already 125mm, I will re duct the shop with 125mm ducting and I'm also looking at changing the 125mm flexible from the impeller outlet to the body of the dust collector with smooth wall ducting and a short bellows for flexibility.
I have worked how to change most machines to 125mm outlets but, one advantage of the 100 mm that I will miss, is the use of dust-right type connecters which suits my mobile machines.
Does anyone know if there is a 125mm version of dust-right?
fletty

Originally Posted by fletty

Being currently on a sabbatical from anything sharp, I've been doing a few light maintenance jobs in the shed. My new 'economy' 2HP dust collector has been in use for a few months and I've noticed number of significant leaks which are evidenced by a dust patch pointing accusatively at the leak site. Even though it will soon be moved outside, there is no reason to put up with these leaks. . . . . .

Good point and well done on the fixes

It's not hard to spot these obvious ones because the amount and size of the dust that comes out of these leave a visible mark . The other place where leaks are easy to spot are around the dust collection bags and filters.

Regular inspections are of course needed to keep on top of these leaks.

The tricky to nigh on impossible leaks to spot are the pin pricks in the collection bags. Since the bag flexes and moves around they don't tend to leave a mark or stain at the leaks site.

Fletty, the best thing I did was get my dusty it's own shed

Originally Posted by fletty

For my portable tools, particularly ROS and Domino, I have been using a cr@ppy, screeching shop vac duct taped to the tool. I have a festool hose and fittings that allow me to plug into a 100mm gate suspended over the workbench but the pressure loss from 100mm flexible to the end of a long 32mm (?) hose is alarming! I am thinking that at least 100mm flex to the bench top and a MUCH shorter 32mm hose might be the go?
I do hate 'half measures' but........

CT2601.jpg

... no more half measures !

fletty