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HVLP Tip Size
Question
Forum Responses
From contributor L: I use ML Campbell's MagnaMax and it has a viscosity rating of 30 seconds in a #4 Ford cup at 77ºF. With my gravity feed cup gun, I use a 1.7mm tip and a 1.9mm cap. They are supposed to be matched, but I find the larger cap gives a better spray pattern. I also thin my lacquer with 7% standard thinner. I end up using 2 coats for a final finish. If I am spraying fully assembled cabinets, I thin to 15% and they get 3 coats. This should give you a starting point to get you going. From contributor R: 1.8 would work best on that gun. From contributor D: Why are you using Sherwin-Williams Moisture Resistant Lacquer? I used to use it until I read the tech sheet. All the finishing has to be completed within a day, however many coats you put on. I ignored this limitation with no bad results (recoat window possibility), but I also did not want to always be a maverick. I like finishing within the confines of a tech sheet. Not only that. As a furniture lacquer, this stuff is too soft for my likes. Compared to retail furniture, like what you get from Thomasville, the Sherwin-Williams lacquers are too soft. I prefer a harder lacquer (I like Kwick Kleen's lacquers). Lacquers differ in how they perform on the pencil hardness test, product to product, brand to brand. Lacquer users do not realize this and the manufacturers do not publish pencil hardness tests on their lacquers. The hardness of a lacquer is just one parameter of the coating that I like to know about. It matters in my selection of a product.
From contributor W: We usually do not recommend the 1.4 tip set. This is an automotive size, not woodworking, and it is generally too small for most wood products, dries the spray, and you have to put down too many passes. Since so little material comes out, many people also tend to cut down the atomizing air, which also decreases the gun's performance. We generally recommend a 1.7 or 1.8 mm for standard wood lacquers and pigmented lacquers. For the thinner lacquers, we recommend a 1.5 or 1.6mm tip set. Many other factors will affect your choice in tip. However, since your gun has the other tips available, you are in good shape. Start with the larger size and see how you like it. You should be able to get a 1 to 2mm build per pass and need 2-3 passes. Some of the factors you can look at are the tip size, the viscosity of your material, the temperature of your material and also your air, the ambient temperature of the room, and the thinning agents and curing times. The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment). Comment from contributor T:
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