Are you looking to buy one or build one? I build my own simple booth with a downdraft ventilation system using box fans and a crude duct made of 1” foam board to exhaust overspray out a window in my shop. Not fancy, but it works fairly well. I generally vacuum it with a shop vac now and then, but I did put plastic under the floor and I have hosed it down lightly a few times to keep dust down and the water evaporates fairly quickly from under the floor if the fans are left running for a while.

@Aaron Jokela Yes, finding where I am isn’t hard, but I have to go to the classroom, scroll down to the first incomplete section and open that and then scroll down looking for the next section lacking a checkmark. It would be great if the home page had a “resume” button like other apps that takes you immediately to where you left off. Just one of those small things that makes an app more efficient.

I am also painting aluminum which adds the additional complication of needing acid etching and then either Alodine or in my case I’m using the Axalta non-chromate epoxy pre-treatment. I just sprayed the pre-treatment on two test panels, one cleaned first with Sprayway and then wax and grease remover and the other cleaned first with wax and grease followed by Sprayway. The good news is that the pretreatment film looks pristine as sprayed, but it is fairly slow drying/curing so I will see how it looks in the morning. At this point I see no difference between the panels which supports your experience that order doesn’t matter. I also used microfiber towels this time rather than the paper wipes I have used previously (wipes made for paint prep, not just paper towels), but paper nonetheless.

I am fighting the same problem now trying to paint an airplane using Axalta products. Getting terrible fish eyes in the epoxy primer. I don’t think it is my air system as the fish eyes are not uniformly distributed on the panels and I have had this problem in the past when spraying waterborne products. The only time my air system was opened was a few months ago when I re-activated the beads in my desiccant dryer. I am wondering if the beads could have picked up grease or something from the oven while I was heating them on a cookie sheet. I am going to buy fresh beads and replace them just in case. My first batch of parts was washed with an aviation specific water-based cleaner, etched with an aviation specific phosphoric acid solution and then washed and rinsed before being dried with compressed air. I then wipe the aluminum down with 91% isopropyl alcohol right before (well, after a few minutes to let the alcohol flash off) tack rag and spray. I then thought maybe the solvent based Axalta paint needed a cleaning with a solvent degreaser rather than just alcohol. So, I bought a gallon of that and used it to clean the second batch of parts, but still did the alcohol wipe down before spraying. Same thing happened and this time I had two long arcs that repelled the paint. So, I am now thinking I either didn’t solvent clean thoroughly enough as the arcs looked like a rag swipe, or the alcohol wipe is causing issues or maybe something is coming off of the tack cloth. I am getting ready to do my third batch of parts and this time plan to clean twice with solvent and not do the alcohol wipe and see how that goes. I am running out of ideas as to what to do differently. My gun is well cleaned after every session and my air system is pretty robust with a coalescing filter at the air tank exit (5 HP, 60 gallon, two-stage compressor) which almost never has any water in it. The system then goes 12’ straight up in 3/4” copper, runs almost 80 feet in 3/4” copper to my paint booth, comes down 10’ to another set of filters and a desiccant dryer. I’ve never seen water in the filter at the paint booth and my desiccant beads lasted several years of occasional spraying so I don’t think any moisture is getting through.

@Aaron Jokela That is an interesting option and even less expensive than the Hobby Air products. How do you bring this into your paint booth? I didn’t see any hose bulkhead passthrough fittings at their web site.

I heard back from both my local Axalta distributor and they said that most of their costumer shops use the 3M organic vapor cartridge respirators. They did say that it was something of a good, better and best scenario and that forced fresh air is the best solution, but also the most expensive and the most cumbersome to use when painting. 3M replied and referred me to their 6000 series mask with 6001 cartridge and P95 prefilter, which is basically what I use now. They also said their forced air products were suitable, but neither the Axalta distributor nor 3M said that forced air respirators were mandatory for spraying isocyanates. So, still somewhat muddy water. 3M also provided me this link as an additional reference. https://multimedia.3m.com/mws/media/1547620O/paint-hazards-tdb-fm.pdf