Today I started by priming the fuselage. I thinned the UVSP per the instructions and went after it. Last time I primed, I had gotten runs and horrible orange peel. So I researched spraying paint on you tube.
I found a wonderful video on YouTube to show me the proper way to set up my gun. It is amazingly helpful. I had most if this down, but had been setting too big a fan pattern. What then happens is an inconsistent application of paint. Here is the video.
One thing that this didn’t explain is what pattern you want to use to spray. Jeff Lange helped me with this a bit.
Firstly, we want very light applications. You want to “mist” on each pass, then make another “mist” pass 90 degrees to the last pass. These two passes constitute a coat since each by itself is light, but the two together have complete coverage. The different directions also helps to average out coverage and ensure we don’t have repetitive misses.
Another thing to note is that you should start in corners. For example, the radius where the strake meets the fuselage side. If you start in this corner and work your way away from the radius, you will minimize pooling and runs in this area. If you work both surfaces into this corner, you end up putting a lot more material in the corner exacerbating the runs and pooling. I learned this one the hard way. It is very important to try to minimize material in this radius because no matter how hard I try we get pooling here.
Another thing about UVSP is that it runs, and more than expected. At the bottom of any vertical surface I have, runs that have formed. It could be because of the former point, but I think it is a combination. Something to be aware of. These runs are not very prevalent at first, but after a few passes they start to show themselves.
Anyways. As I said, I did the first round of priming in the morning. Basically 3 “passes.” What I mean by that is 3 very light, “misted” on applications. I did the first pass, then second pass 90 degrees to that one, then back to the primary direction. By the third application, the runs were so large and ugly I stopped.
I let that dry and blocked the runs out. I also have a quick once over the whole surface. This was cleaned up and washed down. One thing that is great about UVSP is that it dries quickly. Especially in the dry winter air of Minnesota.
After dinner, Ryan agreed to help me do another coat. This time I had a better idea of the patterns required, as described above, to minimize or prevent runs. I have to say it worked pretty well. I should also note that I turned down the paint volume again as well.
Overall I am very pleased with the surface that we were able to achieve. I’m certainly learning about spraying, and can imagine I should only get better with practice. I think that on this round of prime, we should be able to spot sand the runs in the corners and have a flying surface! We will see tomorrow when I get it sanded out.
As an aside, I also did another round on the cowl in the morning session. It turned out pretty well, again it was spot sanded and I am considering the primer done on this piece.