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Pirep: Preval refillable spray system for touchups or small parts

Steve Crewdog

Well Known Member
Patron
These things are buried in other threads, thought the system deserved its own thread.

I had to redo one of the few metal parts on my SeaRey (I messed up and put the Dynon OAT in direct sunlight, and I didn't like the way a couple of the mounting holes came out.) which meant cutting and repainting a new fairing. I had originally used Polyfiber Aerothane, but since it's a 2 part epoxy and I no longer have access to a booth I was stumped how to apply it. Greg, the tech support guru/jedi master at Polyfiber told me about Preval, which is a disposable, eco-friendly, refillable spray can system. You can pay too much and buy it from ACS, or Home Depot carries them at a much cheaper price.

You use it like a rattlecan, but after the first test shot I took the filter off the bottom of the intake tube and it pulled easier.

The only bad thing was after doing the primer the night before, when I went to do my test shot this morning with paint the nozzle jammed ON, sending out a continual stream of spray. In the back of my mind I could hear Richard Dreyfus saying "This is good. I was rusty on panic." as I watched dollar signs of paint getting wasted before I thought to unscrew the bottle from the spray unit, wrapped the nozzle up in a rag and jammed it in the hazmat can, where it sputtered angrily until it eventually ran out of aerosol.

I'm not sure about the finish I got yet, it doesn't look as good as what I got from the LVP gun in the booth, can't tell if it's going to smooth out as the Aerothane dries (it takes about a week for it to really cook off.), or if it was me (I thinned it out as much as I dared), or if it's the limitations of the system itself, but if you have a small repair or are happy with a ten-foot paint job, it'll do.

 

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I have used hundreds of them at day job when we could still do airliner touch-ups in the hangar. Perfect for primer, but seldom had success with finish coat unless the mix was perfect. I tried adapting a Krylon fan spray nozzle but it didn't perform great. Still, I have a box of them and love them for primer jobs.
 
I have used hundreds of them at day job when we could still do airliner touch-ups in the hangar. Perfect for primer, but seldom had success with finish coat unless the mix was perfect. I tried adapting a Krylon fan spray nozzle but it didn't perform great. Still, I have a box of them and love them for primer jobs.
Thanks for the heads up about the finish coats, looking at it this morning it's definetly not as good as with a LVP gun.

I was cautious about the thinning since the thinner Aerothane is, the higher probability of runs, so after grumbling to myself all night, and since I have extra paint, primer, and metal, I'm going to shoot a test piece and experiment to see if I can get the primer to come out better. If that works, then I'll test some Aerothane. And if THAT works, I have another piece of aluminum I'm not using for anything...
 
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How do you get to Carnegie Hall?

I doubt I'm not the only noob builder who has overestimated his abilities and underestimated his skill. Sure, I had sprayed the entire airplane back in 2016, but it turns out spraying with Preval is an entirely different kind of painting, altogether.

I talked to Greg and we both decided that since I had extra paint, time, and an extra sheet of aluminum, Why not experiment? So I thinned the heck out of the Primer and Aerothane paint to the max allowed and sprayed a new sheet. Thinned Aerothane is tricky to spray and not get runs, so I did many, many light coats and only got a couple small runs about the size of my little fingernail in inconspicuous spots.

The first try is the one with holes in it, the second try is the solid sheet. I think it looks better, but there's still a bit of..... I wouldn't call it orange peel, but I would call it texture. It's DEFINITELY not as smooth as what I shot in the booth, but it also might smooth out during the week as the paint sets. I still have to spray the black, I'll use the Preval again. Should be interesting.
 

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Final coats. I messed up the feathering on the bottom, but no one's going to see it except me and anyone who walks up to the airplane. Since it's about a 3 week evolution to paint a new one I'm going to redo it during the winter and get her flying this summer.

Overall, once I learned the proper painting/thinning technique it came out Ok. Not a Lindy, but it's good enough for a 10' paint job. I learned somethings, and I had fun. I'd use Propel again for small jobs like this.

One caution: about 1/3 of the spray heads were bad, either they stuck ON or gave a bad spray pattern, so test before spraying, and be ready with a box of rags to junk the head quickly if it goes renegade. Home Dpot took the bad heads back.
 

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