I should have mentioned I am a hobbyist not a production shop.

The shop is in the basement with the furnance and hot water tank.

The shop is 50' long by 25' wide.

IF my largest project is a cabinet with 10 min of spray time do I really need to be worried about getting the LUL?

The furnance is a sealed burner.  The hot water tank is not.  So vapors lighter than air should be OK but vapors heavier than air could be a problem.  

 

I have aciddently left open mineral spirts, shellac, lacquer thinner and acteone for hours and no fires or flash point.

I know I should never leave the shop with open anything but sometimes memory fails.

 

We will all have a slightly different take on this I'm guessing, but the only finish I would worry about in the circumstances you describe is solvent lacquer (and maybe the catalyzed finishes, which I've not used). I will only use solvent lacquer outside, it's just got too much stuff that can go boom in it.

Michael the way I sprayed lacquer in the winter way back yonder I used two open face natural gas heaters sitting out in the room and lit them early in the mornings and got the temp up to spraying temp then turn them off and sprayed everything. Then after they dried I repeated the process if it stayed cold all day...humidity was my worse enemy in the winter for the clear lacquer would dry hazy white if I didn't check the weather before spraying.. It might be in the thirties out side but I could get the room above 55 to 60 before I would turn the heat off and start spraying..

  Now I chance it using a couple of electric heaters the same way. You would think a person gets wiser as they get older but no for my thinking is, I will turn things off just before there is an explosion. Back then I bought lacquer thinner 54 gallon drums at a time and that sure would have woke up the neighbor hood...

   If I had to clear off the hazy coat I would add some reducer in the lacquer to slow down the drying time and keep adding more coats while the finish was still wet to slow down the process down... Sure had to watch the movement in the shop while the drying took place. I also used a product called Smoothie if cat eyes started appearing in the finish while it was still wet...Pledge polish and wax was bad for the furniture refinishers back then.

   If you are old enough you will remember clear lacquer was very thick back in the sixties. It had to be thinned almost 50% to be able to get it out the end of the spray gun....If you wanted a finish looking like lots of spider webs just raise the air pressure to 100 lbs or so and shoot it straight with no thinner. Little strings would be floating all over the shop...

Thanks all I just spent some time on the internet learning about General Finishes lines.  The challenge with the basement is fresh air.  If I crack a window up hear in NW IN next to Lake Michigan the temp in the basement drops in 15 minutes to below freezing from the normal 50F.  Maybe I should build my project during snow season the finish them in the spring when temps are in the 50-60 F range. 

 

Small patch the problem is the water heater that cannot be turned off the furnace is a sealed system.

 

General finishes has a water based pre cat lacquer that is sprayable out of the can after filtering but may need thining (h20) depending on the equipment you have.  As this stuff is dry in 10 minutes I doubt I could build up enough fumes to get to the boom level espically because it is water based.  But I am now looking at GF high performance water based poly acrylic as my go to finish.  Can be brushed (foam) on or paded or sprayed.   The lacquer for moldings, frames, undersides, doors.  The 2X more expensive HPPoly for Table tops and kitchen cabinets.  Both come in Flat to High Gloss. They also review as the best out there.  I did not know water based Lacquer even existed until an hour ago.

I used to onlyl use oil based poly becuase I was consistently disappointed with water based products.  

I do normally dye the wood to the desired background color (h20 based) with pre raising.  Then when completely dry put on an oil based stain to further bring out (actually reverse) the grain.  Then when dry 72 hours but typically they are dry in 24 hours in winter.  Then top coat with WB poly but here is where I failed becuse I would go to the big box stores and bring home polycrylic which takes a lot of practice to use.  Bubbles do not flow out it runs really easy but does work the majority of the time but the GF HP Poly look much more promising.

So now I need a spray booth with a fan and filter to pull the overspray out of the booth as I paint but I can blow that into the basement and keep the heat in the room.

 

Smallpatch if refinishing assume silicone based contanimation exists and seal it with shellac. Then refinish.

I am old enough to remember the think lacquer but never used it beause I did not know how to use it.

Fred thanks but with GF water based lacquer I don't believe I will ever need solvent or oil based anything on new peices.

 

 

The waterborne finishes have improved hugely over the past several years. Good thing since that's all that will be available some years from now (says me). In any case, don't be misled by the moniker "lacquer" on the label. The waterborne finishes are by-and-large acrylic finishes with different names to appeal to more woodworkers. That doesn't take away from how much they improved or how good they are. I agree the GF products are as good as any available; but the Target Coating products are also very good. They do have the downside of not being available in retail location s (AFAIK) and they come in gallons instead of quarts. There is a new version of a waterborne finish I haven't found any info on though: it's labeled a "modified oil" finish. That one may not be primarily acrylic, or it is. In some emails with Flexner I still couldn't figure out what "modified oil" means, but if want to try one GF Endurovar is one such finish. Flexner did say these weren't new finishes, but have started to gain in popularity.

Hey Michael, a few years ago I ditched my spray equipment, basically because I just don't have a need for it. Back in the day I did quite a few side jobs that involved a lot of flat work, such as cabinets and doors etc. But I got away from that hustle and bustle, toned it all down, and I mainly make things for family and the occasional interested party that wants custom work and will pay well for it.

I really did not like spraying, it was just messy, and the clean up, and the set up, and on and on. I swore to never let a spray device in my shop again, and I don't regret it one bit. For the amount of work I do, it's just not practicle.

 

So I finally made the decision to just ditch it all, it works for me, it won't work for others. But in a shop that is located in a basement like yours, have you considered mastering your wipe on skills? No fuss no mess, and the finish always turns out perfect, because of the simplicity of the application. And there are coatings made that you wipe on, that are very durable. Since we are talking about General Finishes, they have:

 

 

Wipe it on, that's it. I love wipe on finishing, after all that fine work you put into a project, it's just enjoyable to have some music on, or not, birds chirping, whatever, and enjoy the final bliss of the project by quietly wiping on the finish, with out that ruckus of a compressor, and atomized chemicals floating all over the place.

Just a suggestion Michael.