Paint Booths & Safe Ventilation?

[JohnU]

DAYTON Blower,273 cfm,115V,0.77A,1640 rpm

Item # 1TDR3

[Kennyboy]

I am using a direct vent blower from a hot water heater.....don't know the brand of the blower but the heater was a AO Smith.

Works great!

[MeatMan]

I was researching the same thing and found this. It's pretty technical but it gives you an idea of the size/type of blower you need. I guess I need to get on the stick and build mine as well with cooler weather approaching. Good luck.Rob, and thanks for your service.

[sliferkiller]

I was wondering, what the best option would be, homemade? or storebought? I want to spend as least as possibly can but want to have a "safe" booth.

So i have a few questions for DIY booths,

1) will the fan have to be expolsion proof/spark free? Where do i get one?

2) If i filter it, are the expolsive fumes in the paint and will be filtered out or will i still need to be using a spark free fan?

3) which types of paints to spray is the least harmful? acrylics, enamels, lacquer, etc

I am planning to build a metal casing, which is basically free, just the cost of fans, or lights if needed.

I have some questions for storebought booths too,

4) Are the fans there rated for spark free?

May edit if more questions come up

5) if building my own booth would a furnace filter be sufficient?

Edited September 22, 2014 by sliferkiller

[ferrarijoe]

ALWAYS run spark free for paint booth. I run a bathroom exhaust fan from menards. I just got the biggest cfm rated one. Most bathroom exhaust fans are spark free cause if sewer gasses come out of the pipes they can be explosive. All paint can be harmful so you should always wear a mask. I never do but I'm stupid that way. Actually had to go to hospital one time airbrushing lacquer in closed room. As far as filter I use the premium house filters for the furnace. Fumes will go threw those still and cause a fire if using wrong fan. There are plenty of tutorials out there for building a booth. Hope this helps.

[sliferkiller]

i read somewhere that the bathroom exhaust fans were only water tight, being in a more humid environment? can anyone confirm if they are spark free or water tight?

[Miatatom]

I don't think that bathroom exhaust fans are spark free. Bilge blower motors for pumping boat bilges are. They're pretty cheap too. If you can build the case for your booth for free, you've got a big bunch of the cost beaten. Here's what I built for about $240.

http://www.modelcarsmag.com/forums/index.php?showtopic=76088&hl=

[ferrarijoe]

If you make sure the bath fan is a induction motor or brushless it's explosion proof. If you are worried you can get a squirrel cage fan or belt driven so motor is out of booth. I have no issues with mine and I spray lacquer all the time. But it boils down to what you are comfortable with if you don't trust it go another route. I know of guys using range hood fans in their booth and guys using box fans on other forums. Another thing is I suggest making sure the fan blades are not metal. If they hit something they can spark. Chance of fan hit something are slim but better to be safe.

[ferrarijoe]

http://modelpaint.tripod.com/booth2.htm

You should check this website out tells you all about air flow booth setup fans etc. He doesn't like bath fans either but still tons of great info about design.

[jwrass]

As a professional HVAC engineer I submit the following:

1) Any Standard bathroom exhaust fan is not spark free and therefore is NOT explosion proof.

2) They are NOT waterproof.

3) Their is absolutely no correlation between sewer gas and anything to do with sewer pipe connections to a bathroom exhaust fan. In fact it is illegal in all 50 states by code to make a hard connection from a sewer vent to a bathroom exhaust because they are NOT explosion proof. and sewer gas is. I.E. sewer gas and sparks equal kaboom!!!!! The principle of keeping sewer gas from the space is called the weir principle or more commonly a P trap. When the trap is filled with water it creates a seal from the room space to the sewer discharge piping(waste and vent) to prevent sewer gas from entering the space. All venting by code shall be terminated 6 to 8 inches above the roof line. Even if all of your traps should dry up if the venting system has been installed properly there should never be a situation where you should smell sewer gas because the vent termination is at a negative pressure as it relates to the indoor space pressure (chimney effect) if you ever smell sewer gas you have problems in the piping and by all means have it checked out. I have seen the aftermath of sewer gas explosions, not one has been pretty

The intent of a bathroom fan is to remove moisture when you bathe or shower and smell from the space when you drop the kids off at the pool. Nothing more nothing less.

P.S. Please stop using bathroom exhausts for so called booths, they are not intended for that use! I don't want too sound like a jag wad but by definition none of you are building spray booths they are exhaust systems. By definition a booth is a enclosure with treated incoming air and treated exhaust air. Due to a injury that has not allowed me to work since July

10th I have been working on a prototype on and off that will be a scaled down version of the 1:1 types of which we have installed many. It will have fully conditioned incoming air (no more waiting for that perfect day to paint, paint during a hurricane) and fully conditioned exhaust air. Due to my limited mobility It has been a challenge and I'm far from done but to me it is a thing of beauty. All of the equipment has been designed to 1/24, 1/25 scale taken from specifications of a 1:1 booth. I hope it works as good as concept.

P.S.S. Tom I had not looked at your post of your booth when I wrote this. My apologies! Now that's a booth!!!! great job Tom!!! I would be interested how you like it and how it performs!!! Again super job!!!!!

Edited September 23, 2014 by jwrass

[sliferkiller]

oh.. so to build a proper booth i would need to build a fully enclosed case, with two of those glove things attached. I'll look into that and see how it'll work out for me!

Edit: Would something like this be sufficient for a fully enclosed spray booth? http://www.canadiantire.ca/en/pdp/800-gph-bilge-pump-0793507p.html#.VCEYBLFhMtU

Edited September 23, 2014 by sliferkiller

[jwrass]

Jason,

To build a proper booth by definition it would be a fully enclosed. Tom Shirley's design is a excellent example.

The pump showed on your link is a bilge pump and would be manufactured as such to be spark free.

The booth I am building is simple but complex (I know that's a paradox) as it will have variable supply and exhaust speed mapping. A dehumidification cycle with reheat, a heated drying cycle. The intake and exhaust will be filtered.

Parts of my prototype are from pieces of HVAC equipment that I have cannibalized. When I get it dialed in all parts will be new. I am fortunate to be able to have access to these parts to make my Frankenbooth after I do all the testing and am satisfied with it's performance I will build Frankenbooths bride.

All of my components will be 120 volt including the exhaust fan however, the electrical components will not be in the airstream ( much like Paces configuration, check out Paces web site for example)

I don't know if Bills booth was in the trial stage! There is one thing that kills the efficiency of air flow is long runs of flex duct. The nature of this product has a high rate of fiction loss which slows the airspeed down which equals less air flow. I see flex duct on HVAC systems abused every day. Industry standards are there shall be no flex duct from a hard connection no longer than ten feet and in my opinion that's pushing it. We try to keep our flex connections five to eight feet. 95% of my intake and exhaust feeds will be galvanized snap lock pipe and fittings. Even if the exhaust is filtered their will be some of the components that you are exhausting that will pass through the filter and some of what you are exhausting will stick to the ducting. Eventually maintenance will have to be performed. Due to the nature of how the flex duct is manufactured their are bumps and humps that will be prone to having the material stuck to it (if you have ever cleaned flex duct on the discharge of a clothes dryer you will know what I mean) Hard duct is smooth and less prone to having the material stick to it. You will still have to maintain it but not as often and you will have very little to clean. It's my educated guess that if a person does allot of spraying the first five feet of flex duct from the discharge of the booth will pretty much be trash as it pertains to cleaning it when maintenance is performed. One would be better off replacing it vs trying to clean it unless you have allot of time to burn.

Just my opinion! If you are going to build a booth do it right the first time! If finances are a factor due it as over a period of time as finances permit. Do it right the first time! I know I will be building mine twice so I guess I'm not practicing what I preach however, I will have allot going on with mine and I'm sure I will have to adjust or change things ( I already have) I want to do all my tests and changes to the Frankenbooth after that is complete I will build one that is real pretty.

jwrass

[sliferkiller]

Your booth sounds costly to the average person without extra parts lying around, keeping in mind that i am still in school, with no job or anything, would an exhaust system work well enough for airbrushing? Or will i have to wait a couple years until i have the money to "invest" into a proper booth. Would just an exhaust system work since I am a amateur modeler? I might plan on building around the bilge pump I linked.

[Miatatom]

You could go really low cost and find a large cardboard box, a short run of flex tubing and the bilge pump and exhaust the fumes out a window/ It won't do a thing for the quality of your paint jobs but it'll get rid of the fumes. You could go that route and be on the lookout for some sort of box (metal, wood, ?) to serve as a booth later on.

[Miatatom]

oh.. so to build a proper booth i would need to build a fully enclosed case, with two of those glove things attached. I'll look into that and see how it'll work out for me!

Edit: Would something like this be sufficient for a fully enclosed spray booth? http://www.canadiantire.ca/en/pdp/800-gph-bilge-pump-0793507p.html#.VCEYBLFhMtU

That pump is for pumping bilge water out of the bottom of a boat. You want to search eBay for 100 CFM bilge blower.

[sliferkiller]

I was planning to build a metal box as a "booth" to house everything in since i have it in school and we basically make what we want..

[blackandwhite]

I ended up getting this for $100 with the bakers rack and a box of 6 extra filters (receipt was in the box and cost a little over $30 with shipping). Brand new. Never been sprayed in

[Modelbuilder Mark]

Looks like you got a great deal

[jwrass]

Jason,

That is a excellent Idea as a school project!!! The link that Joe Long posted has some really great information! Based on the terminology the author uses it is text book HVAC lingo, I looked it over and I only found one flaw, the rule of thumb for fiction loss in flex pipe is more like 4 to 5 times (he listed 3)

If it were me I would print all of the information there. All the calculations are done and the blueprint he has looks great. I would build it as per plan.

Good luck! jwrass

[blackandwhite]

Took forever yo find. I spent about 2 months searching for items to build one myself, as well as one that was like this.just so happened I was going to Portland from Tacoma Washington for a show anyways and this guy was on the way back home. Need to get the vent tubing and some wood for the window, but I'm ecstatic to finally come across a legit booth

[AzTom]

I'm with James on the the bath fans. Even though they have brush-less motors they can and do fail starting fires when used as bath fans. You don't want paint fumes passing over that motor when that happens.

I question using the boat bilge inline blowers as well . As I understand it, they are designed as just that, blowers. They blow clean air down to the bottom of the boat to force gas fumes out the vents. Although they are brush-less will the motor spark if it fails from paint build up over the years?

That said there are bilge blowers with the motor outside the air stream that would work great.

I am surprised that 100 CFM would be large enough. After you deduct for filter and static pressure of the hose you wouldn't have much left.

[Miatatom]

I question using the boat bilge inline blowers as well . As I understand it, they are designed as just that, blowers. They blow clean air down to the bottom of the boat to force gas fumes out the vents. Although they are brush-less will the motor spark if it fails from paint build up over the years?

That said there are bilge blowers with the motor outside the air stream that would work great.

I am surprised that 100 CFM would be large enough. After you deduct for filter and static pressure of the hose you wouldn't have much left.

Your comment has me thinking. I think I'll be doing a little preventative maintenance periodically. So far, no build up has occurred.

100 CFM doesn't sound like a lot but it pulls pretty good.

[blackandwhite]

I made a thread about a booth as well. Parts tend to add up quickly and so does the time spent ensuring an effective design. Although you can cater it to your needs, sometimes a manufactured booth is the way to go. I searched CL high and low for one, they were always too far away or out of my price range. I was heading to a show about 2.5 hours away so decided to see what was available in that area, and sure enough there was a brand new, never painted in paasche booth. No spray what-so-ever and he had a bakers cart/rack with a wood from for the bottom of the booth to sit on the cart. Also threw in a box of 6 extra filters (the receipt for the filters was in the box - just short of $32)

I paid 100 total for it

The only other thing I want to do is add a light under the front of it and I have an old door from an entertainment stand I might try to fab to the booth to try to turn it into a dryer as well

Edited October 4, 2014 by blackandwhite

[kitbash1]

http://modelpaint.tripod.com/booth2.htm

You should check this website out tells you all about air flow booth setup fans etc. He doesn't like bath fans either but still tons of great info about design.

I used this site when I built my paint booth, I did the cross vent design booth shown and used a squirrel cage fan to vent the fumes outside. It also has a furnace filter to catch the paint particles before venting fumes, lighting is a small florescent two tube fixture. The body of the booth is made of 1/2 inch plywood painted white. I built it with simple wood working tools, except for a table saw to cut the sheet of plywood into piece's. If I remember correctly, it was built, wired and painted in one day and in use a day later. Simple stuff.

Edited October 4, 2014 by kitbash1

[forthlin]

I've been thinking of ordering one of these from ebay since the price seems right. I need to know if you can use lacquer & enamel rattle cans since I don't use an airbrush.