couple of things to mention. if the gun is brand new, do a small project with it before you spray the mast. they pack the guns with grease from the factory and the first time you run material through there especialy something hot like marine poly, it will spit globs of grease on your stuff. learned that the hard way, gun puked on my hood in the middle of the paint job. paint a chair or something then clean her up proper and its ready.
as far as reduction, follow the destructions but stay on the lesser side, you can always add more(cap fulls at a time). test the spray pattern on some scrap material until you get the fan and material flow where you like it before you touch the mast. don't try to put a fat coat on and cover on the first coat, hit a light/med 1st coat, let it flash for 15 mins. or so then another medium coat to cover. whites useually cover real good, reds and yellows not so much. the main thing is not to run/sagg the material. your better off with several light coats than to drench it. don't forget beer...can't paint without it!
I agree with coastrat of this advice. The first thing you should do is run some lacquer thinner or similar "clean" solvent through the gun to flush the needle, cap, and atomizing points. If you have another project to practice on great, but don't sweat it if you don't.
Follow this link for the MFG product sheet that will give you all the specs you need.
http://www.yachtpaint.com/MPYACMDatasheets/Brightside_Polyurethane+eng-usa+A4+Y+20100614.pdfReducing your product should be done based on the size of the nozzel your gun has. Every gun can be different but it's probably around the 1.5-1.7 size range. Reduction should be based on the manufactures recommendation for the product (if it's not on the can call the store where you bought it or check the MFG website,) and adjusted only slightly to compensate for a smaller nozzle or temperature challenges in the curing environment. The reducer you purchased is specific to the spray application because it will allow the paint to be thinned without decreasing dry time and in a lot of cases actually increasing dry times. This will allow you enough time to coat the entire mast allow it to flash off then re coat while the paint is still "open" and able to bond with the consecutive layers. Single stage products can have very long dry times so be sure to follow the MFG direction on this and don't rush it. Don't put to much on the first coat. Thinner coats make for better adhesion to both the mast and each other. Your final coat should be the thickest and around .5 mils and in regular applications will give you the best gloss. Remember to watch your overlaps, release the trigger and re engage at both sides of your stroke, and always work directly in front you trying to avoid crazy angles or blind spots. And one last thing, make sure you drain your compressor really well before spraying. There is nothing more sickening than seeing your work ruined by water contamination. If you live in a really humid area I would pick up an in-line air dryer. Their available for around $5 and screw directly on to your gun in between the nipple. Sorry about the ramble I've been awake way to long and I'm a little jealous that you can even go outside and work without getting soaked.
Once again good luck and post some more pics when your done, I'd love to see how it turns out.
