Explosion Proof Fans and home spray booth set up

Hi,
Can anyone recommend any info on a cheap explosion proof fan- I'm setting up a spray booth and am in need of any tips.

thanks

At about $650, this is the most reasonable I've found. However, the fan needs to be hard wired into your shop's electricity supply, so add the cost of an electrician.

Bilge blower off of ebay. Good luck getting the right power supply for one, though. I tried and ended up using a non-explosion proof fan (a duct boost fan). Having spoken to some local pros about it, they kinda laughed when I told them what I was doing (roughly three minutes at a time spraying a fine spray of nitrocellulose. They said with the fan running concentrations would never build up enough to be an issue even if there was a spark. I do not recommend that for anyone else, though, as I do not want to be responsible for any harm coming to anyone doing this, and I will continue to try to get the bilge blower fan I bought running. I'm going to take it into an old school electrician shop here, see what they can figure out. I tried some LED power supplies that fit the bill on paper, but all they would do in fact was make the motor pulse, on and off, every second. I can touch the fan's leads to a 9 volt and it runs fine, though.

We use them here at my job where they are kept near 1000 gal tanks of stain. The ones we bought were around $650 and they are on pedastals, http://www.globalindustrial.com/searchResult?searchBox=&q=explosion+proof+fan

We make paint and stain and have to have them in our explosion proof manufacturing room. Whats funny is after 17 years working here we never had explosion proof anything in that room until SW bought us out, dumped money into us and then decided to close us down at the end of the month. I wish I could take a couple of those fans home with me they are pretty sweet.

Beau Hannam Ukuleles said:

Hi,
Can anyone recommend any info on a cheap explosion proof fan- I'm setting up a spray booth and am in need of any tips.

thanks

Click to expand...

Gonna start doing your own finishing? Great. I imagine your clients would be willing to kick in a few dollars for a fan, to hurry the turnaround-time sending 'em out ...

Beyond an explosion proof fan, and even more important from a standpoint of accomplishing a good finish, you need a plan to be sure that the big exhaust fan is not stirring up or bringing dust into the spray area. Creating a positive pressure spray booth, with downdraft HEPA filtered air is a good plan.

'Cheap' and 'explosion proof' are not likely, unless you can find a small used one.

Since you are finishing small numbers of small instruments, you could probably get creative in your overall plan to make a good spray environment, and at the same time be pretty safe.

Filtered air is important, otherwise you may be endlessly dealing with dust particles in your finish.

Here's the spray booth I recently put together in my basement. It's built of 2x3s, firring strips, some particle board for the floor and some for the ceiling, and six mil plastic held in place with duct tape and staples. There's a door with an allergy grade furnace filter stuck in it and weather sealing around the edges. The vent fan is outside the booth and connects to a "vent box" inside the booth. The vent box has room for two filters, too. I'm currently only running one in it. Need to find a source for 10 x 20 furnace filters that aren't allergen grade for the vent box. With just one, though, when I have the door closed and turn the fan on (as I do in these pictures) you can visibly see the plastic suck into the booth some what.
http://i.imgur.com/YTtsst9.jpg

Here's a shot of the door. The light source is outside the booth, too and shines down through the ceiling/6 mil plastic.

http://i.imgur.com/fViA3ZE.jpg

The sprayer (still running the Earlex) is also outside the booth.

Steveperrywriter said:

Gonna start doing your own finishing? Great. I imagine your clients would be willing to kick in a few dollars for a fan, to hurry the turnaround-time sending 'em out ...

Click to expand...

I just received my new Fuji Q4 which i got for $675 (instead of $1000) so i hope to be finishing my own stuff but i don't want to start that until i can have a simple but safe and dust free booth (for the reasons Chris mentioned- dust contamination) -
I think ill be making something very similar to Matt Clara's pics- ie- a Dexter kill room with a safe fan

ps- this Q4 is really quiet and i cant wait to use it!!!!

Seriously, check out bilge blower fans. They're made to vent diesel fumes from the bilge of a boat. http://www.ebay.com/itm/New-Marine-...-Ignition-Protected-Spark-Proof-/400309135144 That one's 240 CFM, which should be plenty, but if not, get two, a Y connector and step the duct from 4 to 8 inches. Plenty of people talk about running them on ac/dc converters, I just had bad luck and I'm impatient.

PS. pm me the contact info for the super secret Q4 deal you got!

If you must have a spray booth in your home (I personally wouldn't because insurance isn't going to be easy to get and its dangerous), get a big enough explosion proof motor and set up where you are moving lots of air, like a squirrel cage house fan does. You should pulling as much air into the booth as you are moving out. The air source for removing the lacquer spray should be near the ground. Gets lots of filters and change them often. Lacquer particulates are heavy once sprayed will fall to the floor and stick to the walls creating lots of visible dust which is like gun powder once it is dried. Make sure all sparking electrical sources are no where near the lacquer, wet or dried, at any time, ever. Good luck if you still want to do this.

It is funny, the reputation that nitro lacquer has... I have noticed that people who do not lacquer finish, almost ubiquitously speak of the danger, and the toxicity of nitrocellulose lacquer. Yes, respect, care, and prudence are necessary. However, most people that DO actually lacquer finish, they just do it.... in almost infinite variety of different environments and situations. It is not a big deal. Enter in with knowledge, care, and caution. Pay attention. There should be no problems except for a bit of a learning curve in getting a good finish. Do not create massive amounts of mist in a place where there is open flame, or electrical spark potential. And yes, the dried dust is flammable in the right circumstance, but fine wood dust is equally combustible. I have never seen any dangerous situations from lacquer dust in any of the many places I have sprayed. Depending on where one is spraying, much of the overspray can be directed toward a paint arrestor pad, or some other surface, and it will collect in a safe manner, like some kind of lava formations.. The overspray that collects on the floor, it is not like fine wood dust which clouds up the room as you walk through it, it tends to be a bit more 'stiff' where it lands. Where it lands on, say, a concrete slab, even the overspray from many, many gallons of lacquer is not a serious risk. Fine wood dust is much more of a flammability hazard than dried lacquer dust, mainly due to quality of suspension that can be seen with very fine wood particles in the air, and how long it will stay in suspension. Dried lacquer particles do not stay in suspension nearly as easily. Yes, I have tested to see what the limits are, to try to get an idea of what is not safe in terms of lacquer mist/ dust, dry, wet, mist, solvents, etc.

Bare fluorescent tubes or light bulbs can be an unexpected source of spark, should the glass break when there is a mist cloud happening.

Sure, yes, an OSHA approved spray booth is hands down, the best option. However, safe and satisfactory results can be had in some pretty Spartan situations. With a little ingenuity, a safe and functional environment can be created for effective finishing.

Be careful out there, but no need to be scared.

You should know the codes and permits required. It would be a shame if someone reports you and shuts you down after the time and investment because you are in violation. Secondly, there could be heavy fines.

The ebay person is called

12pierina
They are from Canada (like Fuji)- he (or she) isn't listing anything at the moment.

At the time I bought mine which was just before the listing ended,he had 2 others for sale- they were listed as, and definitely are, totally 'New' and unopened with everything inside still factory wrapped and untouched. In fact the box still had the original outside tape tampered with.

oh- it had free shipping too!!!! Not bad for $675

When I had my booth, the insurance company came in and inspected it and I was so far out of code it made my head spin. I thought the sealed fan would be enough but they wanted sealed lights, no open outlets and ight switches in the booth. I had to get a sealed switch to turn the fan on. I was less concerned about the dust than my utility bill. I'd suck the heat out of my shop in a matter of minutes. I also had an OSHA hygienist come in, disgruntled employee called them, and do air flow testing. They sprayed some aerosol paints with a meter sitting on the table then tested how long it took for the chemical to dissipate to a safe level. The fan was overkill for what I needed. I'd also recommend that you put a filter on the front side of the fan. You'll get lacquer build up on the blades and they'll pull less air.

I found this

http://denver.craigslist.org/for/4601567162.html

i just realised that its a fan- do i need an EXHAUST instead or does the fan create that by pointing it outward???

Beau Hannam Ukuleles said:

I found this

http://denver.craigslist.org/for/4601567162.html

i just realised that its a fan- do i need an EXHAUST instead or does the fan create that by pointing it outward???

Click to expand...

Its tricky. You have to create a bit of a vacuum because you need to draw the overspray/fumes to the fan so it can blow it outside. You can do that several ways but the most common is to build the spray room in a manner that lets equal to less air in to the room than is being blown out. So, you're creating a vacuum. One way to overcome that is to build a spray area within the booth. So, mount the fan on the wall and build a "spray" booth around it. If you just put a fan in the wall then it will pull from the whole room. You have to restrict that airflow so it is pulling the fumes/over spray out.
When I had mine, we mounted the fan in the corner of the room. Then built a wall about three feet deep parallel to the wall that did not have the fan on it. Basically looked like a closet with a fan in the back of it. We built a table 3' off the ground connecting the two walls. We put the spray rig and finishes under the table and the switch around the corner of the small wall. We made a filter box that fit over the fan out of a furnace plenum kit. You turn on the fan, stand in front of the plenum and spray your material then hang the instrument from the ceiling and let the fan to continue to run for about a half hour until most of the fumes have dissipated.

Ideally, the fan will seal to the wall where it passes through.

This is the fan I use, with some louvers on the outside to minimize air leakage when the fan is off. Mine is about 30 years old, but it still works great. I have used it in 4 different spray booths in the past 25 years.


http://www.grainger.com/product/DAYTON-Exhaust-Fan-10E016?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/10E016_AS01?$smthumb$




For air filtration to the actual spray booth, to seriously minimize risk of contamination in your finishes, This filter:


http://www.ebay.com/itm/ATMOS-TECH-...417?pt=LH_DefaultDomain_0&hash=item2ebc599659

With this filter in front of it:

http://www.ebay.com/itm/3M-E736-V-B...442?pt=LH_DefaultDomain_0&hash=item4adb256b0a

and a fabric pre-filter of 200 micron efficiency in front of that,

with one of these fans in between the 85% ASHRAE filter, and the HEPA filter: http://www.canfilters.com/fan_metal_home.html like an 8" H.O. or a 10" H.O., or if you want to move some serious air, a 12" Max-fan (rated at 1700 cfm free air, 1300 cfm at 1.5" wg, and still moving air at over 3" wg! at max amperage draw of just over 4 amps!)




Some creativity is necessary in building a case to house the filters and fan, but this combo will deliver very clean air if your construction methods are tight, HEPA filtered air in quantity. You can deliver it downdraft style directly above your spray area, kind of diffused, to almost eliminate any dust entering the finish.


I have 4 of these 12" Max-Fans in my shop for various air filtration, air moving tasks, and one in a downdraft table that I built that cleans the air with dual industrial V-Bank 85% ashrae filters like this:





There is a prefilter in the downdraft table, above the V-Bank filters and under the table surface.

or just another air cleaner in my shop, for my lungs.. ( still being built in these pics, I then lined the entire box with some serious sound damping foam, notice also that the fan is decoupled from the plywood construction of the box, that black line around the fan box inside, is damping foam with a bitumen layer, friction fit with no wood to wood, or wood to metal contact. This thing is almost silent, and it delivers a LOT of HEPA filtered air into my shop)





One of the air filtration units in my shop has been running 24/7 for over 5 years now, just cleaning the filter element every month or so. In the very few times that it has accidently been shut off, I can see the difference in settled dust overnight.

When I walk into the shop next door, where they have no dust filtration, dust a standard dust collection system, I am SO thankful that I took the time to help deal with wood dust in my work environment!!! I highly recommend it! At least a good downdraft table!


For me, with the amount of lacquer that I spray now days, or say, up to 4-6 instruments a month, my priorities in engineering a spray area would be, in this order, First, that I can spray the finish without contaminants, Second, that however the operations and expected use goes, that I do not have to breathe any lacquer fumes in surrounding areas of my work space during the layup of coats, or during the curing, and lastly, that the lacquer mist is evacuated from the spray space in a safe manner.

Another consideration is what do you do while the pieces are curing? Do you want your C-130 style spray fan running 24-7 until it does not stink anymore? If there is no moving air, a freshly lacquered little uke will stink up a pretty good sized space for a couple days, at least. One of those 4" or 6" can fans and a little ducting, hooked up to a fan rheostat to turn the noise and the air flow down, running constant and exhausting outdoors, will do the trick. After the initial cloud of lacquer is gone, 'explosion proof' does not really matter anymore so these energy efficient, and potent fans are awesome..

It is an uncomfortable place to be, being a small shop but having full on professional finishing needs.... when Tru-oil just won't do...


Sorry for getting so far off topic, rambling on and such..

Andrew was talking about a negative pressure spray environment. If it is lightly negative, this makes it easier to control fumes, slightly less effective at controlling air born contaminants. If a positive pressure clean air environment is created, fumes will need to be dealt with in a slightly different manner, though still with the 'room inside a room as Andrew mentioned, but, air born contaminants are way less likely to enter the finish, and most of those will be passengers on your clothing, in your hair, or kicked up from the floor as you walk in. A 'clean air' curtain will help keep your finish free of contamination.


Or you can just use Tru-oil...

Thank you soooooo much for these well documented replies!!!!!!- they are extremely helpful to someone who can build tricky little things like ukes but has no understanding of so many other things.

Chris- i want to come to your place and fall asleep on your beautiful benches!!!!!- Your workshop is like a freakin $1000 a night Eco resort! hahhahah.

Sounds like an ideal booth would have more suck/exhaust (negative pressure?) while spraying, then after the main plume of mist has been sucked out flick a switch which increases the blow into the booth to create a positive pressure(?) so no dust gets sucked in when you leave the booth. Then turn everything off and have a small can fan to economically suck out the gassing off stage.

What im going to do is:
1- Get that explosion proof fan (with filters in front and behind it) and mount it into a large (7' high x 6 wide or so) open faced ply cabinet with hooks in roof for hanging, and bench top and shelves underneath for finish equipment .
2- Attachable/demountable light plastic walls x 3.
3- Non explosion fan on the outside of the booth blowing into it with filters in front and behind this fan.
4- Small Can fan for economically exhausting gassing off fumes.
5- A door would probably be good too

I presume you put the Q4 generator (or whatever it is) outside the booth?

I HAVE A PLAN!!!- thanks again to everyone for their generous knowledge