DIY Fiberdust collector

Discussion in 'Fiberglass and Composite Boat Building' started by grthammerhd, May 6, 2013.

  1. grthammerhd
    Joined: Apr 2012
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    Location: Manila

    grthammerhd New Member


    I'm thinking of making a homemade dust collection device. Once I've seen a facility where they have huge 3 ft blowers on one end, and 3 ft exhaust fans on the other. The dust that's collected by the exhaust are led down a duct where it's collected by a water basin and the air goes through a filter before it gets blown out back in the open.

    I'm trying to replicate the exhaust part only and I'm thinking of making it portable version with wheels.

    Question is, is the rpm of the exhaust fans essential? Or will a large fan will a low rpm be good enough to suck the microdust?
  2. tunnels

    tunnels Previous Member

    biggest problems with big fans is noise !! continuously it will drive you mad !! but they are able to move large volumes of air and that the main thing !! :confused:
  3. grthammerhd
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    grthammerhd New Member

    Well we're using angle grinders anyway so the noise will be more tolerable than the itchy fiberdust. We are using protective clothing but being here in the tropical Philippines, the heat will just kill you.
  4. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Hi grthammerhd,

    Bear in mind that the air which is being extracted by the aspirating fan has to arrive from somewhere. That's the purpose of the blower you have seen in the facility you've visited.
    If you are working in a closed workshop, it means that you will have to either have a sufficiently big opening towards the outside, or will have to use a blower having nearly the same airflow capacity as the aspirator. It is actually better to slightly under-size the blower (by some 20%), in order to keep the internal working ambient in slight depression. In that way, you'll be sure to have collected and filtered all the dust produced by the tooling.
    If you don't provide a way for the outside air to get into the ambient and replace the aspirated air, you will create a strong depression in the ambient and will reduce the aspirating efficiency.

    As about the fan rpm - it depends on the fan design, of course. Air fans and boat propellers work according to same basic physical principles, so the same considerations on pitch and rpm are valid. You can have a fast fan with low pitch and slow fan with high pitch delivering the same airflow. Depends on what you want or what you can get.

    If you want to reduce the size of the fan, you can consider enclosing just the working area around dust-producing tools with a mobile curtain wall, like these folks did it:


    As you can see, the curtain has the air-inlet opening around the bottom edge, which creates a clearly defined path for the dust - from the bottom towards the aspirating hood at the ceiling.

    In this site here: you can find other useful info for designing your aspiration hood, together with a nice online calculator of required extraction airflow. You could check this well-written design guide too: Exhaust Ventilation.pdf

    Hope it helps.

  5. michael pierzga
    Joined: Dec 2008
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    michael pierzga Senior Member

    Electricity consumption is an issue with big industrial size blowers.

    Best to control dust at the source.

    These grinder hoods are very effective..and cheap to run because they only need a small scale vacume
  6. Petros
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    Petros Senior Member

    you want to build a "cyclone separator", they are easy to make, you put a blower or vacuum at the outlet side which can be outside the building. You can add a water trap at the solids sump end. There is a kinds of fancy math you can apply, but you just need the inlet to come in at a tangent angle to the main drum, and have exhasut up the middle. Looks like this:


    this is a larger one that needs a large squirlcage type blower on the outlet.

    here is a small one made of wood powered by a shop vac.
  7. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I have a home made cyclone separator on my home made extraction system, which also includes a separator plate inside the "containment" area of the collector. There's a fair bit of information about these types of modifications to existing systems, as well as the home made units. Mine is an A/C air handler cage, with a 220 VDC motor, supplying the air, the cyclone is sheet steel and the collector, with it's plate also steel, though the collector is just a 35 gallon drum.
  8. Ironmule
    Joined: Oct 2012
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    Ironmule New Member

    GrtHammerHD, if you're in enough dust to be itchy every day you're in danger of damaging your lungs like I did.

    My diagnosis last year of Pulmonary Fibrosis (scar tissue in the lungs interfering with getting oxygen into the blood) was traced to six months in a poorly run fiberglass boat factory. We itched like hell every night. I quit because I didn't think breathing that much dust was healthy, but I stayed for a while trying to get them to do it right.

    I stayed too long and now I'm one of those guys who carries an oxygen bottle with him into the supermarket. The symptoms take about ten years to become unmistakable, and by then it's far too late. There is no cure once the dust is in your lungs. You can get a lung transplant but that has problems of it's own.

    Treat fiberglass dust like it was radioactive.

    Jeff Smith
  9. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Damn Jeff, I'm sorry to hear that. I have a friend with pulmonary fibrosis and the outcome isn't good. We just lost an industry great to the disorder a few months ago too. Good to see your posts again my friend.

    There are two basic approaches, the most common being a "sucker" setup, where as the low pressure is "drawn" through the network, then deposited or collected. This is how a shop vac works, of course with some bleed off to cool the motor. The other way is the blower, which is what I've done. You need more volume for the blower setup, as you pressurize the network, until a gate is opened, but you run cleaner, as the blower fan isn't involved with the debris, like most suckers are.

    Again, there's a good bit about this on line, though just buying a cheap Harbor Freight setup, could be the most economical and painless method. They don't last long, if asked to do a lot of work, but for a small shop, it probably will last several years.
  10. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    This is a thread I participated in on another forum, where we veered off the topic, into dust collection. Starting at post 31 and onto the next page is a good discussion about home made systems and the effectiveness of baffles, cyclones, etc.

    Something to ponder. A good, well managed and friendly forum, BTW and particularly helpful if from down under too.
  11. tunnels

    tunnels Previous Member

    <insult directed towards other member removed> if you cant look after yourself and work with the proper gear on I have no sympathy for you what so ever .:confused:
    I been glassing for a very long time I am now almost 70 and still as good as I was when I was 45 or so !!and I am on my 3rd wife !! she is only 45 and has trouble keeping up !!
    The only thing I am allergic to is Teak !! I loved working with it but it didn't like me so I have to keep well away from it !!If I smell teak dust in the air in any shop I'm gone !!
    Last edited by a moderator: May 18, 2013
  12. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Tunnels, as I know Jeff on a personal level, aside from participation on this and other forums, I can honestly say, your comments are rude and wholly out of line. We all do stupid things, particularly when young. Jumping to the conclusions you've apparently come to, makes you the despicable idiot, not someone that's made a life altering mistake.
  13. FMS
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    FMS Senior Member

    contradicts his own
  14. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    I gave you negative rep for that, and I hope a lot of other folks do too. It's one of the most irrational, disgusting personal attacks I've ever seen on this forum. What you're basically saying is that Jeff deserves to die, for taking a job years ago and working there six months before quitting because of the conditions.

  15. tunnels

    tunnels Previous Member

    sometime we need shock treatment to jerk us into the reall world as its really is !!

    Yes and over the years I have lost many very close and dear friends as well guys I worked with making boats and in the glassing industry or associated with it !!
    If it takes a seemingly heartless shocking statement to make others think or sit up and take note then I will keep saying and shouting even louder over and over again .:!:
    We will all die from one thing or another sooner or later , I really don't have friends my own age !! because they didn't take care of themselves when they were younger in what ever part of the industry's they worked in !!
    Now I work with younger people mostly as old as my grand children I am always stressing safety , care and concern for what you using not only for them selves but for others they work with.
    Reading about and Understand the dangers of the materials we have to work with in every day life not only at work but at home !!:?:
    Its a chemical world we live in and enough of anything we just take for granted in everyday use can be life threatening if you are explosed for long enough !! :eek:
    My present wife was a hair dressed and had her own business !! her hands were like rhino skin ,so hard and cracked they bleed during the winter just from shampoo and hair colouring solutions .Its taken more than a couple of years to come partly right again !! using honey and brown sugar mixes and sleeping with her hand in plastic gloves some times every night for a week !! :confused:

    If this makes just one person do something right for themselves or for there work mates then all has not been in vain !!
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