Why my extraction system is dangerous. Pictures.

[Graham Orm]

I have changed my extraction system several times over the years and documented some of it on here. I decided to go all out and build a full shop system a few months ago.

I picked up a drop barrel for £15 with an air tight lid, I used some 3" wire reinforced hose from Ebay which really is superb (I'll dig out the link if requested). I used one vac at first which was ineffective over any distance and struggled with the table saw.

The drop barrel has a Thein type baffle in it.

I put 2 vac's onto the same system not really knowing if it would make that much difference, it does. They work well right across 3 metres to the other side of the shop with just the small black vac hose you can see coiled.

The suction is so good that if I forget to open a blast gate it instantly collapses the barrel, so I had to insert this cruciform affair as it takes 20 minutes and a scissor jack to un-collapse it.

The Thein system isn't flawless, and I knew there would be blow through of finer dust. My plan was to enclose both the vac's in a cupboard that was vented directly outside. I didn't get round to it and this is the resulting fine spray from the exhaust, plus a fine layer everywhere in the shop.

My next step is either to build the said cupboard or buy a HVLP vac. and take the exhaust straight outside. Whether this has contributed to my current chest problem we'll never know. However, no more wood working until the exhaust is sorted.

 

[stuartpaul]

Graham,

Might you save yourself some work if you use a HEPA filter vac? You might be surprised how effective they are.

 

[Graham Orm]

Graham,

Might you save yourself some work if you use a HEPA filter vac? You might be surprised how effective they are.

Agreed Stuart, but the filter reduces suction. An external exhaust vent means I don't need to do that. I also plan on running an exhaust from my work vac out of a window when on site and working indoors.

 

[gregmcateer]

Yowser! Thanks for sharing the warning - certainly couldn't have been doing you any good.

 

[shed9]

I had a similar experience when I first started using a Thein based system. I first modified it to exhaust outside after the Thein bin but have since resorted to taking the Thein out of the equation altogether. I now exhaust straight out of the workshop to open land - the intent is to erect a small shed like structure where the chips and dust will settle. There are no filters in the stream and suction works very well. However I still find dust settles over everything over a few days so intend to fit a recycling air filter at the nearest opportunity.

 

[Graham Orm]

I had a similar experience when I first started using a Thein based system. I first modified it to exhaust outside after the Thein bin but have since resorted to taking the Thein out of the equation altogether. I now exhaust straight out of the workshop to open land - the intent is to erect a small shed like structure where the chips and dust will settle. There are no filters in the stream and suction works very well. However I still find dust settles over everything over a few days so intend to fit a recycling air filter at the nearest opportunity.

Where is the dust escaping? You must have a leak surely?

 

[sunnybob]

household vacs aremt made to take that fine dust. Their filters will block very quickly and the motors will overheat. theres a possible fire risk there.
get a fit for purpose vaccum.

One question, every time i see a post that says "vent to outside" I wonder where it goes? if the shed is adjacent to the house, the dust is just blowing into any open window or door, and the whole family is breathing the stuff

 

[Graham Orm]

household vacs aremt made to take that fine dust. Their filters will block very quickly and the motors will overheat. theres a possible fire risk there.
get a fit for purpose vaccum.

One question, every time i see a post that says "vent to outside" I wonder where it goes? if the shed is adjacent to the house, the dust is just blowing into any open window or door, and the whole family is breathing the stuff

Thanks for the input Bob I intend to get a 'proper' one. The outside in this case is a gap between the workshop (which is at the end of the garden) and the back fence. Beyond that is the neighbours garden. I might even construct a vented box of some kind on the outside to try and trap the bulk of it.

 

[shed9]

Where is the dust escaping? You must have a leak surely?

It's not dust escaping from the system as such, it's dust that either isn't initially captured by the system or dust generated with no extraction at source.

One question, every time i see a post that says "vent to outside" I wonder where it goes? if the shed is adjacent to the house, the dust is just blowing into any open window or door, and the whole family is breathing the stuff

In my case, the workshop is well over 200m from the house and the vent exhausts to a 17 acre field. In addition to that, there will be a small knocked up structure that will house the output (we actually use it for chickens, etc) and curtail the dust. I agree that some thought needs to be put into the concept of external venting but I'm all good.