Reading the previous responses there have been a lot of great diagnosis and tips to help you get this paint job correct. First dealing with HVLP, if your not set up from the compressor with the larger diameter air fittings and hose id than HVLP is pretty much just letters on the side of your gun. The gun you are spraying looks like an economy gun so the 1.4 tip is probably a bit small for a high solid single stage. To combat that remove the inline filter in the gun and reduce the 10 percent or more if you need to. Valspar is great house paint but as a automotive finish it is a bit sub par. Take a practice piece of metal and try to push the product to the point of running at varying pressures and with different amounts of reducer.

Great advice. I will try with the filter and play around with the thinner percentage.

The verdict

Had some left over paint so played around with it a bit today. I probably added a bit to much thinner because some of it ran but still a pretty good result. Strained the paint and used no filter. Ran the gun pressure at 40 psi and sprayed about 8 inches from the work and got pretty good atomization. Pretty smooth and glossy finish but perhaps just a little bit if orange peel. Pretty much all the advice on how far you should be spraying from your work is handspan distance. I have reasonably small hand so my handspan distance is only 7 inches. Some people say 8 -10 inches is the desired distance but I guess that can be variable based on the conditions. What is the best distance? On this occasion I was spraying at about 9 or 10 inches and got pretty good results.

The distance depends on the gun. Try spraying 6" from the panel and see if the orange peel goes away.

My Iwata LPH400 likes about 4" from the panel when spraying clear.