Extraction advice needed!!!!!!

[Quetech]

There is a simple solution to the dust problem and it is mentioned
in Bills site.
To achieve the best results the exhaust from any system should
be routed outside the building.
This is the best option for health but may not be for workshop heating.
So this way you can use a high flow low pressure system with a standard
bag filter but just mount the filter outside.

Mike

 

[Barry Burgess]

Cumbrian start off by going down the vacuum route - the choice is more to do with your budget and space requirement/ equipment. I would not go the dust extractor route as Felder said they are the biggest re distributors of fine dust around the workshop and require the addition of filters etc to improve their performance. The filter costs from the woodworking suppliers are way over the top and then some compared to the industrial filter suppliers
Sorry again for being part of the hijack team.
Barry

 

[Jake]

Erm, this is certainly a hijack, but interesting threads are like good conversation; they wander. Just give a yell and folks generally make an effort to get back on track (I know I do, but I do sometimes need to be reminded ). Nearly always better to say something than feel resentful about it anyway.

Absolutely.

 

[cumbrian]

Many thanks to all for your thoughts and advice, both general and specific; it has been very welcome.
As for hijacking of "my" thread, I share Alf's view. I don't feel possessive about the thread I started, and people have gone to a lot of trouble to put their thoughts into words - some of it tangential, but all relevant. All of it is fodder for someone new to the game, and my guess is that others will find the information posted to be useful. I could easily have browsed through a catalogue and picked the sexiest looking machine, happily oblivious as to whether it suited my needs; thankfully I'd picked up enough background information to know to ask my original question. That was a small part of what I have so far picked up by browsing through a lot of postings on numerous topics on this forum. There is an absolute wealth of information; you guys have no idea how useful your postings can be to someone starting out.

Thanks again.

ps What's a DADO CUTTER? No - don't go there......... :-$

 

[Pecker]

no need to appologise, it's probably me that should do that. You just happened to pick on one of the very few subjects that there is a lot of emotive feelings about :wink:

Anyway, don't listen to Alf, hand planes dont need much extraction... :wink: :twisted:

mark

 

[andys wood shed]

This has been an interesting thread.
whilst following it I wondered if their was any tests that could be carried out to see how effective our dust extraction was performing.
I found a Local Exhaust Ventilation report (LEV) carried out by a third party inspector on some wood working machines at work.
The tests he carried out were;
visual
pressure/velocity measurement
smoke test
light test

fortunately the inspector came on site to day so after buying him a coffee
he described the tests he carries out. so if any one is interested i will try to put in into words.

Visual; inspects for any damage and dust deposits around the machines

Pressure/Velocity; using a Anemoeter (hand held) measures the flow by the saw blade which should be 5 - 10 m/s
using a probe he measures the flow in the ducting pipe should be 10 - 12 m/s (if i remember correctly)
and a pressure drop across the filter to see if its blocked.

Smoke test; using a smoke pellet checks around the saw blade guard to see how much vacuum there is and a quick check round the joint to make sure the are air tight.

Light test; he said this is the best test to carry out and is the same as seeing the air borne dust on a sunny day. using a very powerful torch gets a helper to cut some wood with the extractor on and shines the light to illuminate the dust and to see how much is thrown up into the operators face and chest.

This is all detailed in HSG 37 and HSG 55 available from HSE (HSG 37 looks the better document and is only £4.50)

www.dandybooksellers.com/acatalog/Guida ... HSGs_.html


Sorry to go on a bit hope you find this interesting I know its nothing to do with the original question but thought it was the best place to post it.

Andy

 

[Lee Brubaker]

Hi Andy: The light test is used by most hobbyists that I know because it is simple & gives a clear indication of how well the dust collector is working ....especially the filter bags that most use. Simply do the test at night with the lights off and shine a flashlight beam at an angle across the sides of the bags. The amount of dust passing through the bags & into the atmosphere shows up very plainly.Ditto for pleated filters.

Lee

 

[promhandicam]

I always thought that it was the nose test that hobyists used - or perhaps more accuatately the handkercheif test :roll: I was using my ROS yesterday and my own personal inbuilt filtration system needed a good clean out by the end of it. I've personally found chasing out brickwork to be the worst for dust - the nose takes a real hammering.

Conclusion: let your nose guide you as to whether you need to be doing something more agressive in terms of dust filtration. :wink:

 

[engineer one]

getting back to look at my table saw modifications, and i am surprised how much dust manages to get round the impediments you place.

i am trying to reduce the amount of dust that flows to the motor side, and then collect that underneath the saw, so have blocked up lots of places, and the dust just seems to have a magnetic desire to hide from me. :lol:

will report more later this month when i have got it finished.

paul :wink:

 

[Anonymous]

May be the work I do is different to othere -

I do wood turning so
when roughing out I have big lumpy bits,
when doing the finishing cuts I have fine curly shavings
when sanding I use 80 -> 1600 grit - so various grades of fine dust

I, as you will see from previous post, have had built a petz dimension cyclone - no I do not care if its better or worse than xyz model because it has to be better than what I have. Currently have a double bag extractor - this had new bags when I aquired it some 6 months ago. I have only emptied it 4 times so far but in that time I have turned padauk, Oak, Birch, Yew ....... and sanded said same.

I have no machine to measure pressure, current, airflow etc - but its very very very very clear that the bag is badly blinded and hence not delivering what it did originally.

As mentioned I am now installing a cyclone with two big filters. I cannot do this until the craft fair season is over - so a nice Christmas project - I will provide photos once complete.