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If you would be so kind, I am looking for pictures and idea's for explosion proof fan installations. What works? What would you change if you could do it over?

First... Hello again gang! After moving to a location with no workshop for 3.5 years, I am almost back... The new 20'X32'X9' home shop in Chemainus BC (on Vancouver Island) is ready for paint this weekend. Tools, Jigs and stuff are coming out of storage the following weekend. My new 16" VS Jenny explosion proof fan arrived yesterday for the future 6' X 5' corner spray paint booth. Switches and lighting are mounted outside the paint room. Top half of the paint room will be that clear ribbed greenhouse material. I will be filtering air in and out. It came with a seperate aluminum shutters. I'll probably add an outside insulated door for the 6 colder months. May install a small 18" mini roof over the fan and window on that wall to eliminate problems with our 4 winter months of perpetual rain.

You can see my rough 20" opening for the fan in the drywall picture below. The height of the booth room below the fan is 6' 8". My thoughts are to lift a hinged plywood hatch (20" X 50") up to redirect the fan input to the booth ceiling. With the hatch down it can vent the whole shop when needed.

Yikes! I also need to finish building my Joe's 4X4 CNC machine I started 3.5 years ago. That was for carving necks, fret boards and....

Hope to become active again in this and your CNC forum section again by years end.

Thanks

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Rick Hubka
Chemainus BC Canada

It sounds like you are mounting the fan so it pulls air INTO the shop. If that is correct, I would advise reversing this. My Graingers XP fan had an optional louvered cover that opened automatically when the fan was turned on.

My mistake/typo. Yes, it will be an exhaust fan blowing out. TKS.

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Rick Hubka
Chemainus BC Canada

Hi Rick from a fellow BC'er.

I have my fan mounted down near the floor so it draws air and overspray down, not up into my face or onto the guitar body (if hanging while spraying). I also have a filtered opening in my spray booth near the ceiling so that the air is drawn in from up high and the air flow again goes down so I don't get overspray hanging around in the air. Maybe this isn't an issue for fans mounted up higher?

As you can see, I've boxed my fan in and have a filter (basic furnace filter, 20"x20") to catch the overspray. On the outside of the shop, I had a welder friend make up a basic hood with mesh covering the opening so critters don't get in, spiders do but no big deal, they find a way anyway.

Here's a few pictures. Only thing I would change is the size of the booth, I'd make it bigger

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I based mine on Rod's unit and his recommendations (thanks Rod). It vents up through the roof since my shop is in a brick building and I didn't want to cut through the wall. I have not tested it yet but hope to as soon as my challenge guitar is ready. I'll see if I can find a photo.

Basically a box with filters, fan looks like Rod's and is at the bottom of the duct blowing up.

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Steve Smith
"Music is what feelings sound like"

Howdy Rick,,
Sounds like your on track w/the fan and all!
So Im just dropping in a hello, from another BC'er and fellow Islander - Sooke
Cheers
Charliewood

Mine sits about 3 1/2' off the floor. Pretty much shooting right into it. A filter would not be a bad idea to keep the blades from getting covered with overspray. The one thing I wish I had done was put in a bathroom type fan in my spray boot to keep the stink moving outside while it is drying. The 16" is a little much to run while drying. I turn it on from time to time. Make sure you have LOTS of make up air available. They move a lot.

Are you going to the instrument makers show in Errington Rick? It could be fun. Not far from you I think.

Cheers,
Danny

Thanks for the replies!

Barry. I suspect the louvers would stay mostly open when the fan is running but I could get the auto motorized louver option if I spend another $80.

Rod. I guess that's where the word "down draft" comes from. Dam! I could build a 20" wide 10" deep plywood vent right below the fan all the way to the foor and use a small door in front of the fan to redirect it down. Might lose a bit of efficiency but it would do the trick. That would place the input opening and filter at floor level. I really want to use the fan for dual purpose to vent the shop when hot or welding too.

Steve. Wow that's one big round flex vent! You just confirm I need "down draft".

Charliewood and Rod from BC. Nice! 3.5 years ago I was in Calgary and don't miss it. Before that I was in Winnipeg and miss it even less. Ya really need a dehumidifier here in BC for winter though. I have a few tops I braced 4 years ago and the humidity here in winter has them totally go distorted if I'm not careful. I picked up a nice Whirlpool dehumidifier a few weeks back at Canadian Tire for 1/2 price and have installed a through the wall drain for it in this shop.

Thanks for the pictures and help. I'm switching to "down draft" now.

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Rick Hubka
Chemainus BC Canada

I'm finishing building my new spray booth just now, its an extension to my detached garage. I spray mostly nitro, and since I live in the sticks and don't have to worry about complains from neighbours about the fumes (or the design of the thing!), I can do pretty much as I wish. I decided to keep the fan outside, and built this bird house type box for it. At the opposite end of the booth, I have a filtered air intake of the same dimension. I'll show some more pictures when everything is done; I'm waiting for my new compressor, and I'm working on the air plumbing, filter frames, lighting etc.

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Rian Gitar og Mandolin

Arnt, what size fan are you using?

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Steve Smith
"Music is what feelings sound like"

Its about 14 in.

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Rian Gitar og Mandolin

I was just curious - be interesting to see how they perform when we get them up and running. My fan is a 12" unit and I'm also going through about 10 feet of 12" duct so you should get better performance. I'm hoping mine will be satisfactory, at least.

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Steve Smith
"Music is what feelings sound like"

The duct and the bend will really restrict the flow. It's best to have no duct work like Arnt's setup. I used to have my fan installed in a window and it blew like mad. When I moved I had to vent it through the ceiling and roof which required four feet of duct and a transition from 14" to 12" diameter to fit between the joists and rafters. I am probably getting half the amount of flow from it now.

Yep, I know the numbers on the ductwork and that's why I'm hoping it will be satisfactory. The alternative is to cut a hole in the brick in the side of the building - I don't want to do that if I can make it work. Good news is I have 2 gentle 45 degree bends and the entire duct is the same size. The roof vent is a large low restriction type usually found in commercial installations. We'll see.

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Steve Smith
"Music is what feelings sound like"

Hey Arnt,

Any updates? I'd love to see your new spray digs.

Cheers,
Charlton

Rick
" I picked up a nice Whirlpool dehumidifier a few weeks back at Canadian Tire for 1/2 price and have installed a through the wall drain for it in this shop."
I had to buy a dehumid too, however there were too many drafts in my garage shop.... so winterization was in order, sealing drafts in windows, installing & insulating 2"x2" framed, plywood covered floors(less tool mishaps!!!)... also spray foamed an entrance to the crawlspace leading to underneath the house... draft seal the doors... and rerouted the stove exhaust from leading into garage to an outside wall..
[before anyone asks, the stove exhaust was routed there when the garage was still a carport - later to become an enclosed garage - later to become my shop...]
long story short 50% humid heaven which seems to be just fine for my purposes.... now if I could just get out there more..!!!
cheers
charliewood

If you could find an explosion proof squirrel cage style fan they are more efficient when operating at higher pressures. the higher pressure is needed to overcome losses in the 90deg turn and ductwork. In other words, a squirrel cage fan with the same CFM rating would likely move more air the ductwork than a standard fan design. Just a thought.

I have a squirrel cage fan from a downdraft vent-a-hood system I'm saving to use in a spray chamber. anyone know if they are usually explosion proof? I doubt it, but I likely won't be spraying nitro but it would be nice to have that option for repairs etc.

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Formerly known as Adaboy.......

Don't forget about explosion proof lightning in your spray booth...

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"Act your age, not your shoe size" - Prince

Since you ask...

The old “spray booth” was just a shabby structure next to my garage, that also housed shovels, bicycles and the like, so quite rustic to say the least. I did all my spraying in there for more than 10 years, and it taught me a great deal about how to deal with humidity blushing, orange peel, the occasional bug etc. I don't miss it though...




The garage also needed a new roof, so that came off when I tore down the lean-to, but I re-used some of the materials and the foundation




The new addition has one room for gardening tools etc, and another, insulated room next to it, for spraying finishes.




Here’s what you see when you open the door; the ceiling is quite high on one side, so I built an overhead shelf where I can store finishing materials, and it has hooks for hanging instruments while they cure.




My compressor is 5 hp, 3 phase 230V, which is plenty big enough for my needs. It is not ideal to keep it in the same room as the spray I’m told, so I may eventually build a separate insulated box for it next door, and perhaps look into cooling for the air lines if humidity becomes a problem. No trouble yet, so it stays for now.




Speaking of moisture and air, here’s my moisture trap, regulator and air filter, connected with copper pipes and screw fittings. There is also a ‘drop leg’ for draining the system, probably not essential for such a short stretch of pipes, but it is easy insurance. I also have a moisture trap and a regulator at the gun, which allows me to adjust the pressure very precisely.




On the opposite wall is my fan. I already showed the outside “bird house” part which housed the fan itself, here’s the inside. I made this hinged frame over the opening, to hold the filter. There is another one just like it, diagonally across the room, which is the intake, so I can get a pretty effective breeze right through the room. In the winter this cools things down quickly of course, which is not optimal for finsh flow out, but it helps if the room (and finish, and everything it touches) starts out quite warm.




Without the filter, you can see the grille over the duct, and a hinged, spring loaded backdraft damper before the fan outside.




I still have some things to work out, but so far I have been very satisfied with my booth. A pretty big step up from the old shed, anyways.

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Rian Gitar og Mandolin

Where do you guys get your explosion proof fans?

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My question also especially for the folks in Canada.
Tom

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A person who has never made a mistake has never made anything!!!

A good place to start would be to ask at a custom kitchen shop. Most would be using lacquer, and if they do their own finishing, would have to have a proper spray booth. You could also ask at a custom finish/restoration shop. They could tell you where they got their gear from.

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

I found mine on ebay

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Steve Smith
"Music is what feelings sound like"

Thanks for the update, Arnt. That looks pretty amazing. Looking forward to the first batch of guitars that make it out of your new finishing area.

Cheers,
Charlton

Princess Auto used to sell them for about $500. The last few times I've been there I haven't seen any in stock, so you might have to ask or they might have stopped carrying them.