I finally took the plunge and built a polyfilm room in a corner of the shop. Suffering chastisement from my electrician about the dangers of spraying lacquers and my absence of appropriate permits, I removed all electrical sources from the room - all switches and outlets are now outside - and bought an explosion-proof junction box to hook up the explosion proof fan (borrowed) in the window, switched outside the room. Now I get to investigate explosion proof lighting for the room, in addition to the light shining through the clear plastic portion of the walls from outside. If this works out, I will go the code route on the cladding of the room.
I am learning with MLC nitrocellulose primers and lacquers for speed and economy, using a Binks 2001 gun (borrowed). I do finish carpentry, not production, some off-beat kitchens, lots of built-ins and custom trim, some furniture. Basic spraying, even if it is only primer, makes me feel like my product is getting a whole lot better. On jobs requiring top notch finishing, I will continue to send the work out and suffer the scheduling problems.
Any suggestions for solid basic resources from you pros? What would you do if you were setting up for the first time? Other products than MLC (my plywood supplier now carries them, so that seems easy), or strong opinions about guns? Should I go to a pre-cat finish? I plan on sanding in the same room. How about respirators? I am using a 3M 7000 half mask with carbon filter and particulate pre-filter. And what should I do with all the dirty lacquer thinner from cleaning my guns? My guy dumped the first gallon in the dirt.
If you are not going to be shooting conversion varnish, then it is worth a look at waterbornes. They will not eliminate the need for everything you describe, but they are much less prone to explosions and also clean up and thin with water so you have less secondary solvents to inventory and have on the shelf.
Get a good vacuum for the dust or make a downdraft table.
HVLP is beyond wonderful when you are spraying in any enclosed area. My system cuts overspray (versus a standard Binks spray gun) by about 90%, which makes a vast difference in dealing with the problem.
The trouble with nitrocellulose lacquers is that they tend to be more brittle and less adhesive and just overall less durable than I like. I recommend that you try water base finishes. I am currently using Breakthrough for many projects and I love it. The clears are too thick to spray well and so I thin them more than the manufacturer recommends but I have loved their performance anyway. The whites are better for spraying (though they still need some thinning) and I use them frequently. The satin white makes a great primer (finish coat too). I am currently doing a job that uses the clear Breakthrough (custom tinted by me) as a base coat for a distressed and glazed finish that is then overcoated with tinted polyurethane varnish, followed by clear polyurethane for protection. It has exceeded my most optimistic hopes for this application. Fuhr makes a very comprehensive line of water base and waterborne finishes that I have heard impressive things about, though I have been so happy with Breakthrough that I haven't gotten around to trying them yet.
Also, to keep things simple, it probably would be wise to go to water borne. Remember that even though it's water borne doesn't mean it doesn't have chemicals. You need to treat the waste the same as you would any other chemical.
By the way, I wouldn't tell anyone else about what your employee did - that story should be kept to yourself.
We use a pre-cat lacquer at out little shop from a local supplier in the NW. I just love it. After you spray, it?s sandable in about 15 minutes. You don?t have to clean out the pump/gun fearing it will cure in the equipment, even over a long weekend. If you put a little sag in your final coat, it can easily be sanded away and returned to its original sheen with a little lacquer thinner the next day. To me, this product features a great compromise in product protection and ease of use versus production timelines. At $10 per gallon, it?s also relatively inexpensive as far as finishes go.
That being said, if I ran my own shop, I?d go purely water based. I?d do it solely for the health of my crew and myself. With good cross ventilation, an approved respirator, gloves and all the little things I do with nasty, solvent based products, all the employees would just be that much better off. I suppose at that point, I?d have to wonder if the customer would really be that much worse off. We also pay almost $50 per gallon for our small quantities of water based finish. I?m not saying that?s not worth the health risk or dry time, but I can appreciate the choice.
They will analyse the sample and let you know if you can discharge it to the foul drain (sewer, not rainwater) and how much a day you can discharge. You can then pour your washings down the sink or loo.
If this is not so, then contact a local waste disposal company. We also use Safety-Kleen as they supply a solvent parts washer (normally supplied to auto shops for degreasing engine parts) which we use for washing out paint brushes. They come and change the solvent reservoir every 6 weeks and fill in all the paperwork.
The fact that water table contamination is such a big issue makes pouring anything into the ground an egregious act, and one to be avoided no matter what.