Making an adequate extractor/ spray booth

[tom46]

As the deep dark winter and cold days will soon be upon us my attention is now turning to spraying inside in the winter.

Since purchasing my hvlp in April all my spray jobs have been done outside. Come October time i'm going to have to take them inside but in turn turn everything in the workshop white with paint dust.

Would anyone have any suggestions into creating an adequate extractor fan? I'm looking to build something about 5ft in length x 4 wide which I could fit in-between the rafters of my shop?
I was toying with the idea of getting 2-3 extractor fans then running the dust off into a bucket of water. However not sure how effect this would be not to mention all the room it would take up in my tiny tiny shop.

Any help/ advice welcome,
Thanks Tom

 

[tjbnwi]

Here they have to be explosion proof fans.

My set up.

Tom

 

[tom46]

Thanks for the quick reply.

Thats the sort of thing i'm after however in the rafters if possible.

I'm totally new to all things spraying so excuse my lack of knowledge. Do you actually buy the whole extractor as a unit or buy fans and everything separate and construct this yourself?

Thanks Tom

 

[tjbnwi]

I constructed the "filter boxes" out of 2" foam sheets. They are ducted to a remote fan.

Pictures of the back of the boxes and the duct work (kind of, I don't have a good picture of the ducting).

The closer to the source you can extract the better.

Tom

 

[tom46]

Thanks i'm with you now.

So really need so find a suitable extractor to connect to the filter boxes which can be created from insulation for keep weight down with a filter front to them?

Would you know if something like my ctl26 ac with a 50mm hose would be suitable for this?

Thanks Tom

 

[tjbnwi]

Thanks i'm with you now.

So really need so find a suitable extractor to connect to the filter boxes which can be created from insulation for keep weight down with a filter front to them?

Would you know if something like my ctl26 ac with a 50mm hose would be suitable for this?

Thanks Tom

No, my fan is 1550 CFM.
http://www.industrialfansdirect.com/IND-FA-HL-BLV/NFC-NADB8-D-1-E.html

Tom

 

[semenza]

Yeah, you are going to need waaay more air volume moving  a vacuum can provide.

Seth

 

[tom46]

Thanks for the input guys. I guess now the task is to research a sufficient fan with low noise.

Thanks Tom

 

[Jeff2413]

I have a 3000 CFM fan in my spray room which is 12 x 18 with 10' ceilings and I don't even wear a mask spraying solvents. And no I'm not a lacquer junky!  It just pulls it out as fast as I can spray it.  My wife was out yesterday.  In the room while I was spraying.  It works great.  I have a 20" x 20" hole in the wall between my shop and spray room that I built a jamb of plywood and filled with filter material. Finishes off with return air vents for a finished look and I couldn't be happier.

 

[wptski]

I don't even wear a mask spraying solvents.

I have heard of people doing that also that can't even work in their trade anymore.

 

[rst]

I worked in a custom cabinet factory as my first job in 1971.  Laquer and solvent based stains and finishs.  No attempt at dust or vapor  collection back then other than to reduce cleanup...health was not a concern.  Kelly Starrett, the Crossfit trainer guru says your body will let you do stupid things a million times but one day the body will say ENOUGH and then you're injured.  My eyes swell up allergically from wood dust and I get hives around laquer thinner.  I had bought a Trend battery fan supplied face mask and creative engineered dust extraction on the tools I owned before Festool.  The only time I need the mask now is when using my cloud creating Makita slider.

 

[Oldwood]

I think the general rule is 100 CFM for each square foot of booth face. If you are spraying small items you can build a hood and get away with a smaller fan. You need to also supply some air exchange after spraying when the products are off gassing.

 

[Michael Kellough]

And you need to provide clean make up air equal to the volume that is removed.

If it's from the opposite side of the room make sure the floor is clean etc. and it's a good idea to put simple filters on the incoming air opening (protection against leaf debris etc.).

 

[tom46]

Thanks for the input on this.
I'm actually going to be build my filter box tomorrow. 1200mm x 1200mm x 300mm deep. I'm actually going to recycle the air back into the room after going through 45mm g3 grade fibre glass filters then f8 filter bags. I understand the debris from around the room could pick up however working in such a small space I don't have room to change the air and heat the new air.

Hoping this will work.

Oh an I purchased a 2500cfm fan.

Tom

 

[Michael Kellough]

Thanks for the input on this.
I'm actually going to be build my filter box tomorrow. 1200mm x 1200mm x 300mm deep. I'm actually going to recycle the air back into the room after going through 45mm g3 grade fibre glass filters then f8 filter bags. I understand the debris from around the room could pick up however working in such a small space I don't have room to change the air and heat the new air.

Hoping this will work.

Oh an I purchased a 2500cfm fan.

Tom

That should work fine if there is room for the exhaust air to recirculate without knocking settled dust loose.

If the settled dust is a problem (well before time to spray) you can go around with a high pressure air gun and knock dust loose so the (running) filtration system captures it.

 

[Gregor]

I'm actually going to recycle the air back into the room after going through 45mm g3 grade fibre glass filters then f8 filter bags.

Please keep in mind that with cycling the air you create the potential of an unintended thermobaric weapon should you ever spray something based on a flammable solvent or thinner.

 

[tom46]

Thanks for that.

With regards to a thermobaric weapon I will only be spraying waterbased paints however do have and will use a gas heater in the same room? I assume this would all be okay being as it's waterbased paint?
Sorry i'm all new to this haha.

Thanks Tom

 

[Gregor]

With regards to a thermobaric weapon I will only be spraying waterbased paints however do have and will use a gas heater in the same room? I assume this would all be okay being as it's waterbased paint?
Sorry i'm all new to this haha.

As long as the stuff you spray (or any vapors from spraying or drying) isn't flammable you should be ok in terms of not exploding.

Just keep in mind that evaporating water will up the humidity of the air and with a circulation you won't get rid of it, so this will raise the moisture level of any wood objects in the area over time - or can even lead to mold. From that point of view an exhaust from the spray area could make sense to keep that problem at bay.

With the gas heater better make sure to vent the exhaust gas and let in fresh air to not create a oxygen starved or carbon mon-/dioxide enriched athmosphere condition, that could be fatal (or explosive, in case of carbon monoxide) to you health.

 

[tom46]

Mmm thanks for that input. I'm sure my paint isn't flammable but will double check.

With regards to heating I will have to keep a window open even in cold conditions to ensure fresh air coming in.
Or maybe in time get some sort of electric heater for the winter may be better.