Lighting for Spray Operators
Thoughts on how to light the workspace so you can see how wet you're laying down your finish. June 17, 2009
Iím not sure if I am just losing my vision but I just finished spraying a set of cabinets last night and I had a real problem with being able to see how wet I was applying my coatings on vertical surfaces.
The flat work like crown molding and toe kick skins was easy to shoot on sawhorses and easy to see but while shooting my faceframe cabinets which are all on dollys with wheels, I couldn't seem to adjust them to any angle of my lighting that allowed me to see how wet I was shooting over the entire face. As a result, I found a few sags I had to repair and made for a late night. You know the spot right where two drawer rails meet a center stile? I just want to know if anyone has a foolproof way of setting up lighting for this problem. I was craning my neck as I shot trying to get the right line of sight and it was just about impossible.
From contributor J:
Honestly the very best advice I can give you is to spray everything laying flat which means spraying all the unassembled pieces prior to assembly. I fought this idea for a few years, but after I finally tried it I never looked back. It eliminates sags, orange peel, dry spray, and all the other problems you mentioned. As far as lighting I use 8" fluorescents mounted at a 45 degree angle around the ceiling perimeter. This creates a nice "glare" to make sure you have a nice "wet" coat. This will improve your vision at any age.
From contributor O:
I think what typically lets you see the difference between wet and dry is, as suggested, glare (reflection) of a light source on the surface, as if the surface being sprayed were a mirror. If your shop lights are all overhead then the only way you're going to get an appropriate angle to see a reflection of them in a vertical surface is to put your head down below the cabinets and look upward at the work. During the daytime you may be able to see the reflection of sunlit windows instead of shop lights, but you said you shot them last night so I'm guessing it might've been dark out.
From contributor K:
Most commercial spray rooms have lighting at the ceiling facing straight down, lighting between the walls and the ceiling on 45 deg angles that cascade towards the center of the room and lights at the walls, parallel to the floor. Iíve never had a problem in a booth like this. If you donít have a booth maybe you could set up light fixtures in your spray area that simulate this effect. Remember to get the correct fixtures though. We donít want any explosions in the spray room. Also if the walls around your spray area are white, it will reflect the light much better.
From contributor R:
I have seen a lot of guys have problems with Kremlins, air assisted airless or airless guns on rails and stiles because they try and spray horizontally and vertically like a conventional gun. It works much better on face frames to spray in one direction only that way you don't get the double overlap which causes sags. I don't know if that is the problem you are having or not but it made life easier for me when I first started spraying with an air assisted airless.
From the original questioner:
I think I am far too old school a maker to be able to assemble my work after finishing. I typically make all my own parts and my finished end stiles are glued and clamped to the panel stile and require sanding. There are often mitered stiles where again sanding is required. Then there are my furniture grade built-ins where again there just is no way to build like a furniture maker without the need to sand after assembly.
I read a lot on the forums where pocket screws seem to be the answer to every aspect of cabinet construction but I am hopelessly in the past and even my face frame joints are doweled together and not screwed. Great insight on the ways to use lights for finishing to take advantage of glare!
Contributor R, I am shooting with very conventional equipment - Binks pressure pot and Binks 2001 gun. I am happy with the equipment but I can always benefit from those who have many more hours experience with one of these guns in their hand.
I struggle with finding a smoothing shooting pattern every time I shoot face frames where I need lacquer on the edges and faces of the stiles and rails. I try to shoot the edges first, then the faces and keep away from the intersections since they are always "hot spots".
From contributor W:
Contributor R sounds like he might be right! I guess I had to learn the hard way!
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From contributor M:
I agree with contributor R. If youíre spraying with a Kremlin spray in one direction only. The key is to keep a wet edge all the way down the piece.
From Paul Snyder, forum technical advisor:
You could use a portable light to provide side light while spraying. A four bulb spray booth florescent light mounted vertically on a rolling stand works great. Or you could use one of the halogen spotlights on a tripod stand. Another option that works sometimes is to set the cabinet on a quart can so it tilts back when you spray it - the angle will make it easier to catch the light from overhead.
From contributor T:
Contributor R - you might be on to something. Little do they know that back in the day that's how we were taught to spray Ė vertically. Times are changing.
From contributor Y:
What about laying cabinets on their backs and spraying them horizontally like everything else? That's what we do.
From contributor R:
Contributor Y - sometimes that works but not always. I spray a lot of furniture and every surface is seen so laying it on its back isn't an option. Also when you lay something on its back there is the tendency to spray a heavier mil thickness and as a result the flash time is more and you tend to get more dust in the finish.
Vertical surfaces come out much "cleaner" as a rule so it is important to be able to spray vertical surfaces well. A lot of companies that do conference tables will actually mount the table on a frame so it can be sprayed vertically to keep dust out of the finish.
From contributor Y:
I agree with you 100% that vertical spraying does have its advantages for specific applications such as the examples you mentioned. However, if you read the original post it said he was having trouble with his face frames and he attaches them to his boxes before finishing. That said, his trouble was in seeing them in the proper light to gauge proper spray coverage when he sprayed them vertical.