Spray Booth Build - Updated!!

[Richard Findley]

Thanks for the suggestions.

Jeff, I have taken the blue ones off and am now just using the new filter.

I was wondering, because there is evidence of the dreaded black dust on the back of the booth which has obviously been blown out by the fan, could I add a box of some kind around the fan with another filter on, to filter the extracted air? (possibly using the 500mm square filters I originally bought?) Something in the back of my head is telling me it might effect the "suck" though. Any thoughts? If it is possible I think it will pretty much remove all of the dust from the area.

Thanks

Richard

 

[scholar]

Richard

I was reading your thread with interest.

My own experience thus far is summarised here home-spray-booth-lots-of-pictures-t41183.html?highlight=spray and here http://www.woodworkuk.co.uk/forum/viewt ... f=7&t=4763

Based on that experience, I would venture two suggestions, both of which have been recommended by other posters above:

- it would help to add some splayed "wings" to the sides and top to funnel the spray through the filter/fan box;

- I have the same pleated filter as you are using, but still find that some fine dust is emitted through the rear of the fan Based on discussion in the second thread I have linked above, I need to add a dry dust filter in between the pleated filter and the fan; I intend to add a frame to hold this in the middle of the fan box, but have not yet got around to finding suitable filters - the ones you had from Morrells look ideal, so I will follow up there.

I would guess that the fine dust you are finding is getting drawn through the fan as it is too fine for the mesh behind the pleated filter.

Hope that helps - will follow your continuing experiments.

Cheers

 

[lemonjeff]

Richard,
My filter set-up is the same as Davy's in the link I posted, a front (wet) filter then a rear or upper (dry) filter.
The dry filter is a home made jobby out of sheets of pollen filter material, the set-up is only approx 95% efficient but very cheap.
Can you exhaust outside?

Here's some more info http://www.rdmengineering.co.uk/pdffile ... ochure.pdf a commercial booths brochure, it gives an idea of fan airflow necessary for a given booth size.
Also the same sort of info http://www.finishingnews.com/pdf/How%20 ... 20flow.pdf

As JanneKi said you only need something simple to check airflow, when all the booth filters are clean & new I use a sheet of newspaper held vertically then move away from the booth until there's no pull on the paper.

Jeff.

 

[Richard Findley]

Thanks for all of your input guys.

The wings will be going on soon (whenever I get some spare time!!)I'm sure this will help draw more of the overspray in to the filters. Every little helps as they say!

I am well pelased with my little booths performance so far but it does look like my fan is a bit on the small side, esspecially if you look at the last couple of links given .

So my thinking is this: I am happy with the amount of "suck" the booth gives but I am concerned that if I put the other filters back on as well it will reduce the amount of "suck", so my thought was to filter the exhausted air, which I can't vent out side, so I wondered about building a 500mm cube box on the back of the fan and put one of the filters in that. Would that work? From my laymans point of view I see no reason why not but I have a nagging thought it may affect pressures or something and essentially reduce the "suck". Anyone know or is it a case of "suck it and see"?? ('scuse the pun :wink: )

Thanks

Richard

 

[CHJ]

Front or back the results are the same Richard, obstruction = flow restriction, too much restriction results in dispropotionate flow rate loss because the airflow in effect stalls as it can't pass the fan blades quick enough.

 

[Richard Findley]

Thanks Chas. I feared this might be the case! I will fix on some wings and report back with the results. In the meantime I will ponder how I might be able to filter a little finer without loss of suction!

Cheers

Richard

 

[lemonjeff]

In the meantime I will ponder how I might be able to filter a little finer without loss of suction!
Richard

I did think about trying a variation on a drop-box before the fan, there's various posts on here about it for dust collecting.
Essentially the fan sucks the dust through a box with baffles and the dust "drops" to the floor of the baffles. :?:

My box

Will be mounted like this. (I know there should be a blade guard on the P/T )

Will have two outlets, one big one for the planer/thicknesser and a small one for handheld tools. Am planning on installing some ducting around my workshop with various connections for vacuum hose.

Hopefully the box is big enough for this motor, there are no markings on the motor as to how many air it moves only electrical markings. Will keep you guys updated as to how it works, when the ducting parts arrive.

Chris's is big but gives you an idea of the gubbins.

Not a simple or guaranteed solution, that's probably why I haven't tried it yet :wink: