Thread: I hate plastic bags

Bloody good job there.
I reckon you could sell those.
I wonder how much dust leaks past the seal?

Originally Posted by BobL

Bloody good job there.
I reckon you could sell those.
I wonder how much dust leaks past the seal?

What, sell the girlfriend or the skirt?

By eye, there's no dust leaking past - but some coming straight through the calico. However, this:

IMG_1100.jpg

...is the pad for my shed extension, which will house the dust extractor (and compressor).

Was thinking about this the other day. Great solution. Only problem is that the other half would't know one end of a needle from the other (and neither would I).

Originally Posted by sjt

Was thinking about this the other day. Great solution. Only problem is that the other half would't know one end of a needle from the other (and neither would I).

Maybe get one of the doctors or surgeons at work to do one for you, they're usually good with a needle and thread

...great idea and love the shed extension.

Originally Posted by sjt

Was thinking about this the other day. Great solution. Only problem is that the other half would't know one end of a needle from the other (and neither would I).

I could ask her what she'd charge to do another one. God knows you wouldn't want to pay the price I have...

Originally Posted by Acco

Maybe get one of the doctors or surgeons at work to do one for you, they're usually good with a needle and thread

This idea has merit, they stitched me up well and good!

Originally Posted by mhewitt

I could ask her what she'd charge to do another one. God knows you wouldn't want to pay the price I have...

Oh, don't let me get you the bedroom red card. Every step towards the shed gets me a dozen of em'!

Originally Posted by mhewitt

It's a skirt that adapts the separator ring of my dust extractor to a metal bin...

Looks nice. Can i ask what sort of fabric was used? I did see a reference to calico.

Calico would be fine for the outer layer but I would be hoping that the inner skirt would be some sort of rubber-backed curtain material. this would be to ensure that the air had to exit through the filter bag which would capture more of the finer particles than the calico would. (I am assuming that there would be enough pressure in the skirt to press it against the sides of the bin to prevent air escaping between the bin and the skirt.

You are locating the dusty outside the main shed but it will still be in an enclosed space and any dust that escapes the bin will be sitting in the enclosure waiting for you when you go to empty it. Speaking of emptying it, are there any plans to incorporate a means of seeing how full the bin is without having to lift the skirt off it? I have always incorporated a clear perspex window into any dust collector I have built over 20 litres so that you can tell at a glance when to empty it. otherwise if it over-fills it all spills out releasing all that unpleasantness you were trying to avoid straight into the air.

All in all, I see it s potentially a great improvement over the original plastic bag and well done to you and the girlfriend.

Doug

Originally Posted by doug3030

You are locating the dusty outside the main shed but it will still be in an enclosed space and any dust that escapes the bin will be sitting in the enclosure waiting for you when you go to empty it.

If the enclosure is made compact (ie minimal dead space) and the filter has no leaks the air constantly leaving the enclosure will carry most of the dust outside and the amount that remains in the dead space air will be small.

The concentration of any airborne dust in an enclosure can be lowered simply by running the DC for a short period (without any dust making activity). If this is done after every dust making activity the levels inside the enclosure will not be too high. I have done measurements to demonstrate this effect.

The real issue with emptying a DC is when it is opened up where dust levels in the vicinity of a DC will shoot well above and stay over OHS limits for some time - but this is a problem where ever it happens, worse still if inside a shed.

This is yet another reason to put the DC outside (and not just vent outside) a shed although I do realise this is not possible for everyone.

Since
Exposure = Dust Conc x Time
Even if the concentration is very high, the time involved in emptying a DC is small, so the overall exposure if it is outside a shed will be much lower than locating a DC inside a shed.

Great answer Bob, makes sense. A question for you then (hope I'm not hijacking this thread), If I were to put my dust extractor outside then this would obviously involve increasing the point from extractor to collection point. Is there any loss of vacuum the longer the length gets?

Originally Posted by doug3030

Looks nice. Can i ask what sort of fabric was used? I did see a reference to calico.

Calico would be fine for the outer layer but I would be hoping that the inner skirt would be some sort of rubber-backed curtain material. this would be to ensure that the air had to exit through the filter bag which would capture more of the finer particles than the calico would. (I am assuming that there would be enough pressure in the skirt to press it against the sides of the bin to prevent air escaping between the bin and the skirt.

You are locating the dusty outside the main shed but it will still be in an enclosed space and any dust that escapes the bin will be sitting in the enclosure waiting for you when you go to empty it. Speaking of emptying it, are there any plans to incorporate a means of seeing how full the bin is without having to lift the skirt off it? I have always incorporated a clear perspex window into any dust collector I have built over 20 litres so that you can tell at a glance when to empty it. otherwise if it over-fills it all spills out releasing all that unpleasantness you were trying to avoid straight into the air.

All in all, I see it s potentially a great improvement over the original plastic bag and well done to you and the girlfriend.

Doug

Yep, just calico.

As it's to go outside in a separate "shedlet" I'm not too fussed about the blowby. I'm going to leave a larger-than-usual eave - space above the wall, but below the roof - to ensure lots of airflow, as much for cooling as blown-by dust removal.

If it was to have been inside a shed, yes, dust-proof fabric would have been required.

I intend to do just what you suggest - cut a Perspex window into the bin so I can see when it's full. If I was really smart I'd do some sort of remote indicator - like a float indicator on a tank - so I can see when it's full from I side the shed.

Originally Posted by sjt

Great answer Bob, makes sense. A question for you then (hope I'm not hijacking this thread), If I were to put my dust extractor outside then this would obviously involve increasing the point from extractor to collection point. Is there any loss of vacuum the longer the length gets?

That was my original thought - but the answer was (on a 2HP unit, at least), no.

Originally Posted by BobL

If the enclosure is made compact (ie minimal dead space) and the filter has no leaks the air constantly leaving the enclosure will carry most of the dust outside and the amount that remains in the dead space air will be small.

Normally I would agree 100% with that Bob, but when you quoted me as saying: "You are locating the dusty outside the main shed but it will still be in an enclosed space and any dust that escapes the bin will be sitting in the enclosure waiting for you when you go to empty it" I am not sure that you realize that I was referring to not only the invisible dust that would escape from the felt filter bag but also the larger and heavier particles that may be escaping through the skirt if it is made entirely of calico. This dust would have more of a potential to settle in the enclosed chamber and still be light enough to kick up, and be breathed in when someone enters the enclosure to empty the dusty.

I agree with Bob that the smaller the dusty enclosure, as long as it has good venting the more of the particles will be pushed out of the enclosure. But my point was that the addition of heavier, larger particles that can pass through calico would mean that there would be more potential for these heavier particles to drop out of suspension in the enclosure. Then when someone comes in to empty the enclosure they are still small and light enough to float up into the air and be a health hazard.

I hope that explains my earlier post a bit better.

Doug

edit: And I see that there were a few posts made while I was writing this one that explain the OP's intentions a bit more too, but the info I posted should still be a good guide for anyone else doing something similar but not quite the same way

Originally Posted by sjt

Great answer Bob, makes sense. A question for you then (hope I'm not hijacking this thread), If I were to put my dust extractor outside then this would obviously involve increasing the point from extractor to collection point. Is there any loss of vacuum the longer the length gets?

Yes there is, especially if 4' ducting is used, and more still if small radius of curvature joints are used.
However, a 2HP can handle 6" ducting with which there should be minimal pressure loss.
The downside to 6" ducting is the cost, especially of the fittings.
Unfortunately in just about all cases the outlets at the machine are the limiting factors.