Cool!...sanding existing, well adhered paint is the way to go.

The suggestion of Ranthane above is a good one. This is an AIRCRAFT type polyurethane. There is also Aerothane...used to be a competitor...but I think Aircraft spruce bought up ALL of the paint companies and group them together today.

Each brand of polyurethane seems to spray a bit differently and may need different reducer, different technique, etc. Some painters seem to prefer one brand over the other just because it fits their particular painting technique.

I've used Aerothane as well as Superflight...polyurethanes. Hint: the first coat has to be thin, thin, thin...like a dusting. if you try to go heavy on the first coat...it will certainly run. Don't even try to get full coverage or full color...wait for later coats...Once the first coat "tacks up", subsequent coats seem to stick well to the first coat and you can go a touch heavier on the paint....

Follow the directions that come from the manufacturer.

Using automotive paints or farm tractor paints is risky because some of these dry quite hard and "brittle" especially they brittle over time. airplanes flex a lot...so yu want a pint designed to take that. Yes auto paints can use a "flex" additive (used for car's plastic bumpers?..But why not use a proven brand of Aircraft paint such as Ranthane?

I've successfully painted outside. If the weather is warm enough, and dry enough...no problem...windy no good...but a very light breeze will take away the over spray nicely! Painting inside without strong exhaust fans will make a mess of your work as the overspray will build up where you're not painting and leave a rough surface!

Of course there was the time I was trying to get a Pawnee finished ...it was getting late, outside, getting dark ...had some spotlights....got the fuselage nicely painted...then the light attracted a swarm of mosquitos! They are now permanently preserved, and sanded smooth under a couple coats of paint!




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On Friday, November 23, 2018 at 11:23:18 AM UTC-5, wrote:
Thanks to all for suggestions
To clarify
We did not strip old paint
We wet sanded and exposed some aluminum
In random places
The ship is still 95% covered in old paint yet
100% of surface wet sanded
We covered exposed metal with etching primer
We will be spraying without a booth,outside on a dry no wind day