The method I use to prep the parts is simple: I scuff the pieces with a Scotchbrite pad to remove the alclad and create a nice rough surface for the primer to adhere, clean the dust off the parts with unscented dish soap and water, then wipe down each part with acetone to remove any oils or other contaminants. I used the same method for the test pieces and they came out nearly perfect, so I really don't think exposing myself and the environment to harsh acids and chemicals is mandatory.
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| The simple priming prep kit – everything you'll really need. |
Prepping all of the ribs and spars for the HS and VS took a while, around 3 hours. I mixed up the AKZO and took all the parts and the compressor out back while waiting for the 30 minute induction time to expire. Once the primer was good to go I poured it through a filter into the spray gun, then took it out back. I connected it to the compressor, ensured the pressure was set correctly at the compressor and at the gun, got close to the first couple of parts to be primed, pulled the trigger, and watched dumbfounded as the sprayer splattered primer all over itself, the ground, and pretty much anywhere except onto the parts. Ah %#$&;!, the gun crapped out on me at the last second!
I only had an hour or so of daylight left (the humidity skyrockets after the sun goes down) as I made a frantic attempt to clean the gun with paint thinner, but the results were the same. My guess is that I didn't clean the spray gun well enough last time, and whatever primer got left behind hardened and blocked parts of the gun and the nozzle. The spraying ability of the gun is most likely permanently reduced. The day was ending, and I felt defeated. I took the parts back in the garage and called it a night. All of that work, and nothing to show for it.
I considered going out and buying another Harbor Freight gun, but I didn't want to run the risk of having another spray gun fail on me because I couldn't clean it properly. These HVLP guns have a lot of parts that need to be disassembled and thoroughly cleaned to avoid ruining the ability of the gun to atomize the paint properly, and I don't want to go through that again only to ruin another one.
Doing some research, I came across some builders that used airbrushes and airbrush-like spray guns to prime everything. Airbrushes are nice because they keep the paint and air components separated until they come together to atomize the paint into a spray. This makes cleanup a lot easier and make the gun itself less prone to malfunctioning after multiple uses. The downside is that most airbrushes have a small paint reservoir, typically only a few ounces. That's fine for sessions with fewer parts, but having to constantly refill the sprayer when priming a lot of parts or priming large parts such as the skins would get annoying.
Eventually I was introduced to the Critter spray gun, which functions like an airbrush but has a much larger paint reservoir in the form of a 16-ounce mason jar. It's typically meant for staining and painting decks and fences, but I figured it'd be worth a shot since I saw it mentioned by another builder on the VAF forums. I went ahead and ordered one on Amazon (free 2-day shipping is a wonderful thing), so I can try it out this weekend and hopefully fix this mess.
