adapt this idea for a small spray both?

[Bob Blarney]

Hello,  the illustration is old-timey, but the concept is still valid.  The air jet powered by vac creates a strong draft while also minimizing and exposure to fumes.  Additionally it reduces fire/explosion hazards that are probably not a relevant issue in hobby installations.  It may likely be possible to miniaturize for benchtop use.

 

https://books.google.com/books?id=P-IDAAAAMBAJ&lpg=PA599&rview=1&pg=PA785#v=onepage&q&f=false 

[Jaager]

Wearing a tie anywhere close to a lathe- really insane.  

[kurtvd19]

2 hours ago, Bob Blarney said:

Additionally it reduces fire/explosion hazards that are probably not a relevant issue in hobby installations. 

Bob;

I agree that it does reduce the danger by providing extraction of the hazardous fumes.  However I take exception with the rest of your statement that "fire/explosion hazards are probably not a relevant issue in hobby installations."    I say this a retired Chief of Fire Prevention with a lot of experience with spray painting.

 

If the air to fuel mix in and around a spray area - regardless of hobby or big scale - reaches the lower explosive limit, the hazard is at least equal and possibly more in the hobby use just because in most home areas there are absolutely no safety features found in large scale painting areas such as proper electrical connections, sealed conduits, etc.  

 

Just because one only sprays occasionally doesn't make them immune to the laws of nature.  If the area has a fuel/air mix that falls between the lower and upper explosive limits of a flammable liquid and any source of ignition is within the area, a fire/explosion is very likely to happen.

 

I have seen the results of thinking this isn't an issue for the small or infrequent use as well as by the frequent users with big spray booths with all the safety features who do spraying outside the booth because it was only a little job.  Auto body shops are prime examples of this - and a source of significant numbers of fires.

 

Please don't ignore the warnings on the paint containers to use in a well ventilated area as there are also health concerns about breathing the same fumes.

 

Kurt

 

 

[Bob Blarney]

Point taken, thanks

Hmm,, manometer gauge might be useful for development to calculate airflow.

[Bob Cleek]

Hey, those were the days, weren't they. You need to read on to understand how they managed to get away with spraying lacquer and venting the fumes with a vacuum cleaner, or turning on a lathe wearing a tie and long sleeves. (It seems everybody wore a tie and long sleeves, even factory workers, in those old photos... it was a sign of social standing, actually. If you didn't wear a white shirt and tie to work in the early 1900's, you couldn't afford to be buying Popular Mechnics, dontchaknow?)  About five pages down, you'll see the answer, "Smoking Camels Calms Your Nerves!" I guess it was not smoking that turned Americans into a bunch of pansies afraid of getting hurt doing anything.

 

Darwin Award contestants who spray volatile solvents indoors and operate lathes and other stationary power tools wearing jewelry, ties, long sleeves and hair and the likedeserve the prizes they win. It's just a natural part of the evolutionary process. It's God's way of culling the really dumb ones.

 

 

Edited May 30, 2019 by Bob Cleek

[vossiewulf]

1 hour ago, Bob Cleek said:

Hey, those were the days, weren't they.

At the custom furniture shop I worked at, we used solvent lacquer, did have TEFC motors on the spray room fans, but the spray room guy typically turned off the fans before spraying the final coat, more than half the time without wearing a mask. It would literally be a cloud of lacquer in there through which the spray room guy could only dimly be seen. He thought he got a better finish doing it that way. I and all the other people told him he was completely whackadoodle to do that, he never listened. No idea what happened to the guy but I assume he didn't live to a very old age. On the up side the spray room never exploded, but we were waiting for that too as he was a smoker.

Edited May 31, 2019 by vossiewulf

[CDW]

Just about everything but taking a bath could include a long sleeve shirt and tie back then. 

[Bob Blarney]

17 hours ago, Bob Cleek said:

Hey, those were the days, weren't they. You need to read on to understand how they managed to get away with spraying lacquer and venting the fumes with a vacuum cleaner, or turning on a lathe wearing a tie and long sleeves. (It seems everybody wore a tie and long sleeves, even factory workers, in those old photos... it was a sign of social standing, actually. If you didn't wear a white shirt and tie to work in the early 1900's, you couldn't afford to be buying Popular Mechnics, dontchaknow?)  About five pages down, you'll see the answer, "Smoking Camels Calms Your Nerves!" I guess it was not smoking that turned Americans into a bunch of pansies afraid of getting hurt doing anything.

 

Darwin Award contestants who spray volatile solvents indoors and operate lathes and other stationary power tools wearing jewelry, ties, long sleeves and hair and the likedeserve the prizes they win. It's just a natural part of the evolutionary process. It's God's way of culling the really dumb ones.

 

 

O Wise Man - enlighten us as to how you spray in your present workshop.  

As a former research scientist in surgery,  I've seen the sad results of ignorance (poor training),  carelessness  (failure to follow training) and equipment failures (which sometimes do happen).  I'm aware of how fume hoods are used in laboratories and some aspects of their construction.  I'm looking for a practical small booth that would work on the scale that most hobbyists would use, say a cubic space of 24" x 24" x 24".  In this setting, I would expect that the most hobbyist would use 'rattle spraycans' which emit far less paint with  far less overspray than an automotive or furniture factory installation.  I think the most significant hazard would be inhalation of organic solvents in a hobbyist setting, although stupidity is always possible.  

As for lathework, here's my current setup - a sand-bedded lathe with excellent lighting (and a great stereo!),  high airflow dust collection with accessory shrouds for sanding and finishing.  (The dust collection cyclone and filters work down to about 2 microns.)  When roughing out logs, I use a logger's helmet with full faceshield, earmuffs, and a leather apron (and a dust mask if necessary). This gear is not usually necessary for most model builders.

 

 

 

 

[kurtvd19]

Some photos of my airbrush station and associated stuff. 

 

The spray booth - just out of the box.  Badger sent this to me several years ago to test.  I liked it and use it for all but larger hulls.  Has the proper explosion proof motor and wiring.  I added a nylon stocking to the exhaust duct that I added coming off the back that catches some fine particles that get past the filters.  If I use it for solvent based paints I add a piece of duct and move it over to exhaust out the window.  But it's not an issue 90+% of the time as I use acrylics almost exclusively.  I don't think Badger ever sold these units but there are similar units on the market.   If you only use acrylics a spray booth is a DIY project - but, in my opinion, if you use solvent based paints unless you have the knowledge and access to the specialized class of electrical components to use with flammable liquids it's best to purchase a properly built booth.

The photo below shows the booth after a lot of use.

 

My set up is contained on a hospital patient table that adjusts for height (I used to use it for rigging until I vowed to never rig any model with more than a single mast).  The spray booth sits on top and the compressor sits on top of the base in a small tray I made.  The black rectangle on the flex arm is a 3 level LED light that has greatly increased the lighting for my set up.  As it's outside the booth there isn't any concern about paint over-spray getting on the lens.  The filter needs to be replaced soon.  I have two filters with the front one being discarded when dirty and the back one then becomes the front one with a new filter piece behind it.

The arrangement of Airbrush holders and accessory items w/o the spray booth in place.

My airbrushes now all have quick disconnect fittings so I have eliminated multiple hoses and having to bend down and change the hoses (with quick disconnects) at the regulator.

 

I keep my paints in a file cabinet I got when a pharmacy shut down.  The drawers are sized for prescription forms so the paint bottles are not lost in a deep drawer.  The drawer pulled out and the two below it hold all of my paints.

The nice thing about having the set up on wheels is I can put it into an alcove when not being used freeing up floor space.

 

Kurt

 

 

 

[Bob Cleek]

9 hours ago, Bob Blarney said:

O Wise Man - enlighten us as to how you spray in your present workshop.  

I won't claim wisdom, but I've been around the block a time or two and still have everything I was born with, minus a few brain cells, I expect.

 

My present workshop is a dedicated 1500 square foot building with an overhead fan, a large floor fan, and two large moveable pedestal shop fans, I didn't invest money in these. I just picked them up here and there over the years. The shop has a "clean room" where I do my drafting, rigging, and such. The rest of the space has windows and a large sliding door about the size of a double-space garage door. All of my stationary power tools are on heavy roller bases so that they can be moved as needed.

 

Anytime I'm working, the door is open to the outside, unless it's particularly cold or pouring rain. Anytime I do anything that creates dust, (e.g. table sawing, wood lathe turning, power jointing, thickness planing, sanding) the machine used is rolled at least to the open door, if not onto the concrete pad outside the door, and the fans positioned to create a good breeze exhausting air from the shop to the outdoors. Afterwards, I vacuum or blow off all the dust and shavings from the tool with compressed air and roll it back to its storage spot in the shop. This keeps most all of the dust out of the shop. It just blows away. I live on a farm and don't need to deal with neighbors worrying about where the shavings go.

 

Similarly, spraying of any volatile materials is always done outdoors, or in front of the open large barn door, with fans to move the air from inside to outside. I do spray solvent-based coatings from full-size commercial-type Binks sprayguns, as well as HVLP spray equipment. I rarely spray any coating from a "rattle can," due to their expense and often poor quality results. (One can't condition paints or adjust the spray shape and volume with a rattle can.) I do use an artist's airbrush to spray solvent-containing paints in my shop at the bench. I generally run the overhead fan above my main bench, which keeps any fumes away from the area, although the amounts of material coming out of an airbrush are generally so small as to not be any major consideration.  I also use exhaust fans to vent the entire area when working with acetone for cleaning jobs and such.

 

I wouldn't necessarily advise these techniques for those who work at their dining room tables, however.  The famous yacht designer, L. Francis Herreshoff, had his metal lathe set up in his dining room, but he was a life-long bachelor, and that may explain why.  I should disclose that over a lifetime,  I've acquired professional experience working in a furniture factory, a machine shop, on commercial painting jobs, and several commercial boatyards. I've seen a couple of guys lose fingers in table saws, another send himself to the ER in an ambulance sanding antifouling paint off of a boat bottom without wearing a particulate mask, and I once carelessly put a heavy-duty grinder into my own kneecap, a result of fatigue and a moment's inattention while grinding rust off an iron keel. On balance, I've seen a lot more Darwin Award entries in commercial settings by professionals than ever by do-it-yourself-ers, but that's probably because there's a lot more opportunities to do stupid stuff when one is on the job working all day every day. I am pretty well familiar with OSHA regulations and I consider myself a very careful worker in any hazardous activity. That said, I am aware every time I turn on a power tool that I am risking serious injury, which is probably why I've still got all my fingers. Also, I don't do that for a living, so my odds are better on that basis alone.

 

I'd never discourage anyone from using what they believe to be the safest way to do anything and I sure won't accept any liability for anybody else getting hurt doing it the way I do, but I will say that I've never found the need for exhausting spray boxes or booths at all when using ordinary paints and varnishes. That would, I'm sure, not be the case if I were shooting car finishes on a production basis or lacquer finishes in a furniture factory paint shop, and there's no way I'd ever spray any LPU coating, even outdoors. without a good mask and separate breathing air source. Neither would I want to spend a working lifetime in a furniture factory with clouds of fine dust hanging in the air without wearing a good particle mask. With a small DIY shop and relatively occasional exposure, minimized by blowing it all out the door, I've never felt the need to invest in ambient air dust filters.

 

When airbrushing models and I am concerned about overspray making a mess, I will take a cardboard box and use it as a "backstop," just as the exhausting spray boxes are used, and simply throw out the cardboard box when I'm through with it. (Some care occasionally does have to be taken to avoid "back spray" from sprayed material swirling around in the box, though.)  Although I've seen workable homemade spray boxes that use standard furnace filters to separate particulate and ordinary shop vacuums for exhausting the vapors out the back, I've always preferred good ambient ventilation over vacuums... blowing rather than sucking... because my major concern has always been combustion risks much more than inhalation risks. I prefer to have good air blowing the bad stuff away from me and into the great outdoors. Both dust and volatile fumes can fairly easily "go boom" once you suck them into a hose.

 

In all of these things, one must exercise good judgment in balancing all the risk factors, realizing that there is a big difference between occasional exposure and frequent, long-term, exposure to toxic materials of various types as addressed by OSHA regulations. It's always a good idea to study the Materials Safety Data Sheet ("MSDS") on any new product used in the shop and follow all safety instructions.  If you want to spend hundreds, if not thousands, of dollars on dedicated plumbed shop dust collection systems and vacuum spray boxes and booths in a hobby workshop, knock yourself out. You might do well, however, to remember that a lot of the stuff probably sitting under the sink in your kitchen right now which, if you don't use it safely, will kill you quicker than most anything you'll ever encounter building ship models. The best safety device of all is an properly engaged human brain.

Edited June 1, 2019 by Bob Cleek

[mtaylor]

There are stray booths here that folks have constructed using a variety of materials (depends on the builder).  They're scattered though... some in build logs.   There is one going on here and I"m sure there's more: 

 

I used the search function with key words like "spray", "booth", "paint".   You might even try Googling for designs.