Does anyone have any plans (here we go again) for a portable or knock down spray booth?  Small projects that can be sprayed from an aerosol can are no problem, but sometimes I would like to be able to use a spray gun on larger projects.  My shop is in the basement, so I would need a way to capture or exhaust the fumes safely.  This would be in a hobbyist, and not a production scenario.  And no, I have not yet checked out local zoning issues, I would do that before implementing a system that seems viable. 

Tom, if it's knockdown, and if you are performing the finishing process as a hobby shop, I don't think you even need to worry about zoning issues, I could be wrong, that is IMHO.

Without looking at plans, and there are plenty out there, going off what I recall, you could make a knock down area from PVC piping in any configuration you'd like, where the PVC joints are separable after use, then plastic sheeting is draped over the PVC pipe framing.

 

You can use a standard old area box fan that many of use in our own homes, and you would then secure a panel filter to the box fan, and face the fan so it blows out of the temporary finishing area with the plastic sheeting spring clipped around the fan. Your entry way into the knockdown booth would simply be a split in the plastic sheeting.

 

How does that sound? I know a picture is worth a thousand words, but I thought I'd try to describe it to you from recollection. I could tell you to go search google for plans, but you could of figured that out on your own, you came here for ideas, not to be told to go search google! Ok, so now you all know how I feel about telling someone to go Google it! I hate it! One of my pet peeves around here, but hey, the intentions are good.

 

I do more-or-less what John suggested. It would work for you, but I don't ventilate. My PVC is a square frame about 8'x8' that I hang from the ceiling on some of those bike hooks. The plastic draping I use is actually shower curtain liners I bought from Amazon. They come in several lengths, and I bought the 8' long ones to make sure they hit the floor. They hang from they PVC with plastic shower curtain hooks (the reason I bought them) and it goes together and comes apart reasonably easy. I think you could probably set something like this up around a window and have a fan suck the vapors out...if you spray non flammable finishes.

Thanks John.  I had envisioned something similar, but wasn't sure if a box fan plus a filter would sufficient to catch fumes, or if I should figure a way to also vent to the outside.  I agree with you on Google.  It is a valuable resource, and I don't think any of us need to be told to "go search Google".  A specific link is welcomed, but "do your own homework" is not.  Whenever someone on a previous site would say "Google is your friend", I would be sorely tempted to say "my finger is not yours!"  Sorry if that was inappropriate.

2 minutes ago, Fred W. Hargis, Jr said:

I think you could probably set something like this up around a window and have a fan suck the vapors out...if you spray non flammable finishes.

Thanks Fred.  I am a complete novice when it comes to anything other than a spray can, so I have to ask, I assume you are talking about water based finishes?  What are the differences in water based spraying vs oil based spraying?  Is the clean up pretty much the same?  What about results, any concerns there?  This sound like I am asking for a tutorial, nothing so involved, just trying to learn from your experiences.

No matter what arrangement that you choose, you have to use your head. You will be working in an enclosed space (basement) so be very thoughtful about spraying solvent based materials that will off gas VOC's (volatile organic compounds). This includes using alcohol as a carrier for water borne finishes. Not a good move, unless you have a sealed booth and a proper exhaust system to get rid of the fumes/vapors. Ignition sources are all over the place and get enough VOC's in the air and it may ruin your day.

 

As for the booth, Woodsmithshop.com has a plan for a fold down plywood booth that can mount to a wall and fold up flat when not in use. It would be OK for smaller projects. However, if you are going to be spraying larger item, then I would consider building some type of enclosure that provides an adequate space to be able to walk around the project. A wonderful tool would be a lazy susan table to be able to spin the project 360°.

 

The suggestions about the shower curtains is a great arrangement. You can make it as big as you need and still control over spray migration, dust, etc., but you have to pick and choose your materials.

 

If you are going to spray potentially flammable finishes, then I would consider moving the operation out of doors or to an outbuilding.

13 minutes ago, schnewj said:

If you are going to spray potentially flammable finishes, then I would consider moving the operation out of doors or to an outbuilding.

YES! Above all else, this is a great option, then the only thing you need to worry about is outside elements, dirt, dust and flies and gnats getting stuck in the finish, but that's why you have the portable knockdown, it then can be used as a dust screen for out door work.

Great suggestion Bill, and so obvious.

Here is an idea to go with the plastic, would probably work with the shower curtains too:

 

http://www.lowes.com/pd/CinchTite-Tarp-Zipper-Door/3369316

 

Also, there are these:

http://www.rockler.com/fastcap-3rd-hand-hd-extension-5-12?utm_source=google&utm_medium=cpc&utm_term=&utm_content=pla&utm_campaign=PL&sid=V9146&gclid=CIyE87mxg88CFQOUaQodY7oOjw

 

They can hold the plastic tight to the floor and to the ceiling. Also, they are great for hanging cabinets and other things when you are by yourself and a 3rd or 4th hand would be helpful.

One other consideration that a lot of folks don't think about. Plastic and vinyl will build a static charge. So, be very careful about using this material around finishes using flammable carriers. If you are not ventilating the space properly and the VOC's (fumes) reach their UEL (upper explosive level), then a static discharge could cause a flash.

 

I don't mean to scare anyone, as this would probably have to be the "perfect storm" for a hobby type operation. However, it is a condition that must be considered.

 

The main thing to consider, whenever you are spraying a flammable carrier is ventilation, plain and simple. Oh, and a box fan is not the right tool. Suck a flammable right past a sparking motor and just wait for the flash.

Typically when I spray waterborne finishes I find the overspray dries and falls to the floor as a white gritty powder...that would be the acrylic resins in the finish. They sweep/vac up easily, and if you are ventilating that dust will be blown out with the vapors. Even with waterborne finishes the vapors have some health risks, so no matter what finishes I'm using I wear an organic vapor 1/2 mask. The "organic vapor" part are charcoal filters to catch the bad stuff, available for most of the better quality respirators (be sure to store these in an airtight container to make them last longer). The problems with spraying oil based finishes are that 1) the finish doesn't dry quickly, so anything the overspray touches becomes a sticky mess. It doesn't clean off easily, so you have some work getting things back to normal. 2) kinda the same thing as 1...that sticky stuff will stick to fan blades and whatever, besides being flammable. You can use the fan to force air into the booth area (positive pressure) and solve the sticky on the blades problem but it's still not optimal. One other thing on the subject of clean up, cleaning your spray equipment of oil based is more work and takes more expensive cleaning agents than waterborne. Using soap and water (waterborne) is fairly easy, thought the steps are the same. But use paint thinner, mineral spirits, and such makes it more expensive, a bigger mess, etc., etc.

Edited September 10, 20169 yr by Fred W. Hargis, Jr

All great ideas and I've been looking for something like this, as well.  One point of clarification, though.  It's not the UEL that is the danger level, but the LEL (lower explosive limit).  If a substance reaches/exceeds it's UEL and has not ignited, it won't until the level drops back into it's explosive range.  If the concentration is between the LEL and UEL, you're in danger.

Thanks for all the ideas and suggestions.  Sorry it took so long to respond, but I had some major  computer issues.  Dell tech support now own about 6 hours of my life.  I think I will put the spray booth on the back burner for awhile.  I don't have an outbuilding, and right now my garage is full of everyone's junk but my own.  Plus I have a 68 Javelin in there, to be at least made in running condition, and probably sold, so I wouldn't want to take the chance of over spray on that.  Thanks again, all.

22 hours ago, FireJohn said:

All great ideas and I've been looking for something like this, as well.  One point of clarification, though.  It's not the UEL that is the danger level, but the LEL (lower explosive limit).  If a substance reaches/exceeds it's UEL and has not ignited, it won't until the level drops back into it's explosive range.  If the concentration is between the LEL and UEL, you're in danger.

 

You are correct! The danger zone better defined as the LEL. The UEL is the point where the concentration (ratio of air to fuel) inhibits the ignition point. What I should have said, was UNTIL the UEL is reached...

 

Thanks for catching that, John.

 

However, I still say that most hobby type operations are not really a problem as long as the person uses his head. Ventilation is the key. The better the ventilation the less chance of the fuel mixture reaching the danger levels. Keeping the fumes away from an ignition source is what is generally overlooked. Box fans are terrible for flammable fumes, as are lights, and even a static discharge from walking on the floor while spraying.

 

Industry spends big bucks, on explosion proof; lights, electrical, tools and equipment, and static suppression. All in an effort to inhibit ignition sources. The price of this stuff is way out of the average hobbyist's wallet (or what he is willing to spend). However, that doesn't mean that a thoroughly adequate spray area can't be achieved.

If you all like Jeff Jewett's books he talks about this.  The idea is to filter the air coming in to keep it clean (dust free) and use and explosion proof motor on the exhaust to the air outside.    Mine will be a room sealed off from the rest of the basement with a fan to draw in fresh air and exhaust it outside thru an opening.   The common house fan is retrofitted with and explosion proof motor.  The filter on the door frame is common heating filters that do capture all the dust and other stuff.  The air rate depends on the volatility of the compound and the respirator used.  For shellac low and no respirator and the same for most all water bone finishes.  For oil or lack I use medium while spraying then low for drying.  The over spray is contained in the room on the floor and walls.  Then fan blades and exhaust port cleaned monthly.  The inlet filters 2 times per year.  I wear a white suit and it never leaves the clean area.

The PVC and plastic will work in a common area but the fan should be routed outside or not used and the respirator always used.

 

On ‎9‎/‎9‎/‎2016 at 5:44 PM, Fred W. Hargis, Jr said:

I do more-or-less what John suggested. It would work for you, but I don't ventilate. My PVC is a square frame about 8'x8' that I hang from the ceiling on some of those bike hooks. The plastic draping I use is actually shower curtain liners I bought from Amazon. They come in several lengths, and I bought the 8' long ones to make sure they hit the floor. They hang from they PVC with plastic shower curtain hooks (the reason I bought them) and it goes together and comes apart reasonably easy. I think you could probably set something like this up around a window and have a fan suck the vapors out...if you spray non flammable finishes.

Same here as far as the shower curtains if the area is small, otherwise cheaper to buy a roll of heavy plastic sheeting and add the grommets. The "open" area in my shop is in front to the garage door so I hang the plastic from the garage door tracks and bend hooks from heavy wire.

Just read some parts of Flexner's book this weekend.   He has a section on a part-time spray booth and exhaust fan.  Either Jewitt's or Dresdner's books on finishing, maybe both, have a set up on using cardboard boxes or sheets of ply and a box fan to make a knock down spray booth.

 

BTW, Flexner's finishing book is my absolute favorite resource.  Jewitt's "Complete, Illustrated Guide to Finishing" is also good and it's advantage is a lot of photos, and each topic covered in about 5-7 pages.   Don't care so much for Dresdner. I read Masachi's book this weekend, too.  Some nice topics on coloring, especially using glazes (which I use a lot of), but not as good as the first two.

22 hours ago, kmealy said:

Flexner's finishing book is my absolute favorite resource

Keith, I have a book by Flexner, it is a 1994 edition.  Is yours a newer edition?  I would be interested in reading his thoughts on a spray booth.

1 hour ago, PostalTom said:

Keith, I have a book by Flexner, it is a 1994 edition.  Is yours a newer edition?  I would be interested in reading his thoughts on a spray booth.

Yes, I have both first and second editions.

2d edition (copyright 2005) pp 30-31 talks about spray booth for non-production shops.   Most of that information is here

 

First edition does not talk as in much, if any, detail about spray booths.

 

Jeff Jewitt's version, normally described as being facing out of a garage

http://www.finewoodworking.com/2007/11/01/make-a-simple-spray-booth

 

If working in a basement and venting to the outside be sure you have a fresh air supply and do not back draft your hot water or furnace.

For example I have a walk out basement.  My basement door open so the spray goes out that door then I have an adjacent window that is fully open to act ad the fresh air supply.  Both the door and window are far enough away from the furnace flue to cause a problem.

Now watch carefully the temperature.  If the temp goes below your minimum for the finish wait for warmer weather.  Trying to add any heat is not good.  I will admin sometimes I apply cold then close up the shop and allow the finish to dry warmer.  I am not talking about trying to spray when it is 20F outside.

 

I have a challenge for you all I am starting building more in winter than summer due to summer activities.

If my finishing room is bring in fresh air from the window and exhausting it out  the door how would you maintain a comfortable temperature level.

Spraying lacquer in 20F temps or anything oil based would be challenging.