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Beau Hannam Ukuleles
09-08-2014, 06:52 AM
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

mzuch
09-08-2014, 07:44 AM
At about $650, this (http://shop.standardequipmentco.com/10Expand.asp?ProductCode=D1633X&gclid=CjwKEAjwp7WgBRCRxMCLx8mMnDMSJADncxS2C2nM5Bze AFpl7NRHuraiviG8Gk2Vi_WxdjKruAzVABoCvhfw_wcB)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.

Matt Clara
09-08-2014, 07:48 AM
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.

ericchico
09-08-2014, 07:58 AM
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.

Steveperrywriter
09-08-2014, 09:53 AM
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

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 ...

Chris_H
09-08-2014, 12:22 PM
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.

Matt Clara
09-08-2014, 12:42 PM
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.

Beau Hannam Ukuleles
09-08-2014, 01:32 PM
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 ...

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!!!!

Matt Clara
09-08-2014, 02:31 PM
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-4-In-Line-Bilge-Blower-41841-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! ;)

BlackBearUkes
09-08-2014, 04:15 PM
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.

Chris_H
09-08-2014, 06:38 PM
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.

Dan Uke
09-08-2014, 09:35 PM
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.

Beau Hannam Ukuleles
09-09-2014, 03:22 AM
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.

Beau Hannam Ukuleles
09-09-2014, 03:23 AM
oh- it had free shipping too!!!! Not bad for $675

thistle3585
09-09-2014, 10:10 AM
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.

Beau Hannam Ukuleles
09-10-2014, 12:33 PM
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???

thistle3585
09-10-2014, 03:18 PM
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???

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.

Chris_H
09-10-2014, 03:49 PM
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-INDUSTRIES-ATMOS-AIRE-GASKET-SEAL-HEPA-FILTER-35-5-8-X-35-5-8-X-3-/200728483417?pt=LH_DefaultDomain_0&hash=item2ebc599659

With this filter in front of it:

http://www.ebay.com/itm/3M-E736-V-Bank-Minipleat-Filter-24-x-24-x12-85-Percent-Efficient-MERV-14-/321504242442?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:

https://farm4.staticflickr.com/3695/9084792511_9440b84219_o.jpg (https://flic.kr/p/eQMWiD)

https://farm4.staticflickr.com/3676/9084795357_20dd376d77_o.jpg (https://flic.kr/p/eQMX9H)

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)

https://farm9.staticflickr.com/8527/8571996731_5ac3cc8898_o.jpg (https://flic.kr/p/e4tHZ6)



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..

Chris_H
09-10-2014, 04:18 PM
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...


;)

Beau Hannam Ukuleles
09-11-2014, 07:09 AM
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

thistle3585
09-11-2014, 07:55 AM
Beau,
I had a production woodworking shop and was spraying 25-50 products a day, so I needed a dedicated booth and fan. I think that may be overkill in your application. We were spraying lacquer in our large booth and the OSHA guy told me about a table top unit that would suffice for when I was doing small projects. I'd look at table top or hobby spray booths. I'm guessing you're talking about spraying 1-2 instruments a week? You can get a complete booth for as much as you may have in the fan alone. Check ebay for some used ones. Some of them are even ventless. Here is an example by spray tech. Everything is contained in one unit.

Beau Hannam Ukuleles
09-11-2014, 09:54 AM
Hi Anderw- that unit looks pretty good-

I just bought a 16" explosion proof fan for $275 which I will build into basically what is shown in your pic- a cabinet with filters at the back and the fan behind them- all enclosed in plastic cube with door and window with filters.

Chris_H
09-12-2014, 06:07 AM
That unit looks cool for spraying non critical finishes, or, very small items, or ukes if it were installed in a clean room.

For spraying grain filled, polished, high gloss finishes, clean air is practically a requirement, otherwise a lot of time will be spent dealing with individual dust particles that settle in the finish. With filtered, dust free air and clean clothing, and a little basic clean technique, a 'recipe' can be developed for the finish that is desired. Coats can be built up quickly, with the actual spray time of each coat barely taking any time at all. One little dust spec in a sprayed coat throws a wrench into the whole thing. The polished, deep high gloss finish acts like a magnifying lens for any contaminants that happen to embed in the finish during application. Picking them out with a razor knife leaves a dent, which messes up the accuracy of the desired dry-film end result by the time the little hole is filled/ or sanded out. Trying to sand out some dust particles when the finish is still soft cured often just pushes the dust deeper into the finish, again messing up your finish' recipe'. In addition, sanding of troublesome particles is not fun! Effectively removing a dust particle that has settled into wet finish, and potentially touching into the softened previous coat requires waiting until the finish has cured a bit, more than an hour unless the lacquer is very thin. It is so much better to be able to do any sanding as it is needed on the instrument as a whole, not fighting dust. To be able to spray a coat, come back an hour later, spray another, and so on, without having to wait for the finish to cure hard enough to sand out the offending mess.

At the upper end of instrument finishing, knowing exactly how thick the dried film is, will play in to getting a consistent sound. This requires consistency in finishing technique, not chasing the whims of what happens to land in the finish during each spray session.

Spraying furniture grade finishes in satin, or even gloss lacquer is quite a bit different than spraying a gem like high end finish. In furniture grade finishing, a spec of dust here or there hardly matters. Not so with polished gloss little gems.

Lacquer can be sprayed quite effectively with zero fans at all, just walk into an undisturbed room, spray quickly, and leave, being careful to not stir up the dust with any airflow from the spray gun, or your feet/ movement. No fancy anything, just a spray gun and some abrasives. A properly designed spray booth is a tool that saves a lot of time in the long run if one is doing lots of really fine finishing. It can take the element of contamination and minimize it substantially. Time is money, and fixing finishes sucks.

Say someone finishes 40 ukes per year. If in the finishing process, they have to add another hour in dealing with contamination for every instrument, sanding at unknown intervals to keep it clear and smooth, not even counting the extra time to wait for finishes with contaminants to cure until they can be safely sanded, that is a lot of valuable time in the course of a year. Enough to justify some effort in cleaning things up.

Stink is not the biggest enemy in finishing. Getting a good finish is what is most important. Just because one stays safe, or doesn't make a mess with lacquer dust, that does not help at all if the finish is not good.

By the way.. another benefit of spraying lacquer at or near a 100% thinning ratio is that any potential contaminants can be removed more easily, as they are not embedded in as thick of a coat as they would be, say, if the finish were being sprayed straight out of the can in fully wet coats.


In a good spray booth setup, or a good location, contamination should not be much of an issue. Really, you do not even need a spray booth at all to achieve a very nice polished high gloss finish. A spray booth just makes it a lot easier to get there.

Dan Uke
09-12-2014, 06:28 AM
Chris,

You should get into the uke spraying business. I bet would do well!

Daniel

Chris_H
09-12-2014, 06:37 AM
I have sprayed my lifetime recommended allowance of lacquer, but yes, you are probably correct. Guitar finishing also.


I am just beginning to explore binding, purfling, and inlay into my plinth work.

In the long term, there is a lathe and a mill in my future, for some specific audio related products. :)

Thank you Daniel.

Matt Clara
09-12-2014, 07:15 AM
Hey Beau, I didn't realize you meant a qualified cheap. I thought you meant cheap like me! ;)

Moore Bettah Ukuleles
09-12-2014, 07:24 AM
Good stuff Chris.
My spray room measures about 8' X 8'. The interior walls, ceiling and floor are all made out of heavy duty vinyl and made for easy removal and cleaning. I used to be in the art show business so I used my old art tent for this. (They are the ones you see at street art shows.) The better ones run around $2000 but you can often find used ones for a couple of hundred bucks or even free sometimes. Many even incorporate zippered doors in them. The cheap Big Box Store tents won't work. The walls I have are very thick, translucent, durable (I've had this one for 20 years) smooth and waterproof. The walls zip together with heavy duty zippers for easy removal. My floor is a single piece of linoleum that is laid on top of my existing floor. I periodically hose everything down and clean it well. I never spray toward the wall where the fans are. Instead I spray toward an adjacent wall on which I hang a 3' wide piece of kraft paper that runs from the ceiling to the floor. This is simply tacked on and replaced often as overspray builds up. I won't mention what kind of fans I use because I don't want to be responsible for anyone's misadventures. BTW, one of the reasons I like using an HVLP system is because the lager particle size produced keeps the air cleaner.

Beau Hannam Ukuleles
09-14-2014, 09:04 AM
Chuck-
Your market vendor tent thingy is a really good idea for easy setup and breakdown. I only want to keep the booth up when spraying a batch and not all the time.

Previously, i was thinking of something similar to Japanese style walls with plastic instead of rice paper, but the market vendor tent (at least the frame) has benefits over this,

Mark Roberts Ukuleles
09-17-2014, 12:27 PM
Beau, Black Bear is right on.
Ideally, the CFM of the fan needs to meet or exceed the internal volume of your closed spray booth.
A 6'x6'x8' booth would be 408 cu ft. so a 240 CFM bilge pump wouldn't be sufficient by most standards.
You also need to decide where the intake air coming into the paint booth is coming from....since you live in Colorado.
If it's coming from your shop, it will be sucking your heated shop air right outside. Might get a bit chilly in winter.
Most serious builders booths that I have seen are rigid construction with sealed sheet rock walls.
Often they will use a sliding glass door for the front.
Additionally, you might look into some kind of speed control for your fan. After you've sprayed for several hours and the instrument is in the flash-off stage, you may wish to reduce the airflow tip it has completely based off, which could easy exceed a day.
Good luck.

Mark

Chris_H
09-17-2014, 07:13 PM
Partially correct. In a booth that is engineered to this standard, inlet air is filtered, and well... not just a passing thought of some filters that kind of work, kind of not... Strong airflow without filtration means that you will just be creating expensive sandpaper. Honestly, you do not really need ANY airflow. What you need is ZERO dust settling in the finish. With zero airflow, however, the lacquer mist will become similar to dust. ( though it is small, shrinks, melts in, and is clear) However, if the gun is set up right, and/ or you are using a turbine driven HVLP, the amount that settles in the finish in the first 3-5 minutes, which is when the finish is still the softest, the finish just cures the slightest bit hazy, and most often it can be sprayed right over in the next coat. Downdraft filtered airflow acts like a 'curtain' in protecting the freshly sprayed finish from having particles land in it. This is how top level spray booths are designed.

If you engineer a booth solely with the parameters of (given) volume, equals such and such airflow, without the inlet air being completely filtered, and also without thought to the direction, and other qualities of the the total airflow in the room, you will just be moving dust into your finish, guaranteed.

One nice spec of some airborne particle is going to slow you down, a lot. More airflow, if it is unfiltered, means more potential for dust.


The reasons for high airflow in a booth are to minimize overspray from landing in the finish (which is an insignificant problem in comparison to dust or other foreign contaminants) and also MOSTLY (where spray booth regulations come from) to protect the operator. In reality, it takes very little airflow to keep overspray from being a problem.

Double or Triple layer, glued 5/8" drywall construction, with a sliding glass door, and excellent filtration on the inlet side, and enough airflow so that the operator does not really even need to wear a respirator, YES! that's awesome! That is how a spray booth really should be built. If you cannot quite muster that, In my experience, clean air is WAY more important than quantity of airflow.



With the only design parameters being considered in designing a booth as being 'x' amount of airflow in ratio to a given booth volume, and not exacting consideration to filtration... well, good luck with that.


And, if you are sucking unfiltered air into a booth from a woodshop, that is a recipe for a lot of work and inferior finishes.



Those Can filters, like this: http://www.canfilters.com/canfilters_150.html connected to an 8" can fan with insulated flexible ducting, and then led into an industrial HEPA filter, or at least an 85% ASHRAE filter would make an excellent filtration system with minimal effort, and the carbon filter will work well when run as a circulating fan in the shop for particulate matter and also for residual solvents. I have had one of those (the 150) running 24/7 in my shop for 5 years now, It is awesome. It is almost silent. For the first year or 2 of the filters life, it will also work for solvents. I have owned one of those metal box woodworking filters with the squirrel cage and the cloth bag filters. Those are a total joke to a setup like I just described. Aside from clogging immediately, with severely reduced airflow, squirrel cages are noisy and energy inefficient.


I guess I should also state, that if you are doing lower or average grade lacquer finishes, like satin, or unfilled, unpolished finishes, you can get away with a less exacting environment. I am talking about how to cost effectively ( on the cheap) spray a tip-top quality, fully polished gloss finish. The kind that, honestly, I do not see too many builders doing, and many that do hire the finishing part out. Of course, just having the booth and a good gun/s does not account for spray skills, and experience based intuition.

Matt Clara
09-21-2014, 02:18 AM
I find it hard to believe that one couldn't produce high-quality high-gloss finish without double or triple glued dry-walled enclosure with a sliding glass door, et al., but perhaps I'm misunderstanding the suggestions. The suggestions given to me by the local pros included: filter your incoming air to keep dust out of the booth, filter your outgoing air to keep spray from building up on your vent fan, air intake source should be up high up in the booth, outgoing air should be lower and directly under whatever it is that you're spraying, or near enough as possible, because the overspray is heavier than air and will naturally want to fall, cfm should equal or exceed booth volume, otherwise you're not moving enough air to keep the fumes from building up and possibly escaping the booth altogether, seal the booth up best you can to keep the air coming into the booth restricted to the filtered intake vent, and clean your booth regularly to generally keep a clean environment. I think the idea of positive pressure is genius, as it pushes the air out rather than sucking it (and potentially dust) in.

Timbuck
09-22-2014, 02:43 AM
Talking of explosion proof electrics ....I have a sparkless stop start switch , it consists of two mercury contact beakers.
Sealed in glass in a switch casing....the idea is that this switch connects to a relay breaker placed at a safe distance outside the danger zone, so no sparks occur when switching the fans or other equipment on and off.....It was designed for the petrochemical industry.....I've never found a use for it.

Beau Hannam Ukuleles
09-22-2014, 04:06 AM
im going to use Japanese rice paper style walls, but with heavy plastic.

Each wall will have hinges and with cheap yoga matt rubber running up the wall edge that squishes together when at a right angle to form an air tight (enough) seam. (yes the yoga matt will corrode with acetone but not very fast with just fumes and over spray hitting it- i might seal it with shellac) I will do the same on the wall edge that sits on the floor, the weight of the booth will be enough to hold it down tight. along with a temporary plastic floor.

I've not thought much about a door and intake/outtake windows- something utterly totalitarian no doubt.

thistle3585
09-22-2014, 04:45 AM
I build at home but spray at my work. I have my HVLP 3 gallon pot sitting on the floor next to the back door and I walk outside, spray the instrument then come back in and hang it up in the corner of my warehouse out of the way. So much for high tech. :)