Bill,

Not a good idea! When the 2K topcoat hits the fiberglass with balsa core it will bud and cause wind turbine blades to grow there. If you don’t catch this before it is too late, you will have a 90 foot turbine blade wedged inside the house, and no way to get it out….

The Divot

Dave, one of us doesn't know what you are talking about.

Don’t say we didn’t warn you.

Sorry Bill.

I just used the KlassKote clear over their colors, even over white. That avoided the quantity/limited life issue of 2K for me. Yes, there is a slight yellowing as cured (probably from the hardener) but unless you are going over white, I don't think you'll ever see it. I ran tests on two airplanes that I painted white. The first refinish job was specifically to do this experiment, so I base-coated with the white, then applied some Monokote numbers, then clear-coated only the wingtip with the numbers. This let me evaluate the contrast side by side. The slight tinting shows up in some lighting conditions more than others, which is likely what you noted and are trying to avoid. At certain reflecting angles (lower incident angles) you can't easily see the difference. I note that with an iphone 10 camera, it doesn't seem to pick up the difference at all, whether under outdoor light or indoor. Obviously, that is just a distraction as I tried to show the difference by taking a photo, and what really matters is what people actually see....

A comment one of my flying buddies who was a professional painter made has stuck with me. That white was one of the most difficult colors to match when painting cars because there are so many different hues, and everyone tweaks it to suit their taste. I can't knowledgeably comment on where in this range the KK white is, but it seems pretty neutral, not much blue and not much "warmth" added either.

I would note that the paint job on this sample plane is likely over 15 years old now. As far as I can tell, it hasn't "yellowed" more with age. Yellowing might be accelerated by prolonged UV exposure, but I didn't test for that. My race planes don't get out every month for practice any more. Aging would be a concern for any clearcoat.

I have put KK colors over different spraycan primers, usually the Rustoleum Auto Primer, with zero issues so far. I generally let the primer cure for a week or so, mostly because I don't like painting and it is slow work for me.

In the future, I will try not to review endless reports on turbine blade disposal issues, pending anti-dumping laws for turbine blades (Sweetwater, Texas?), and alternative disposal methods such as grinding up and burning the fiberglass/epoxy waste stream in cement manufacturing plants....prior to replying to a perfectly good question on Stunthanger.

Again, my apologies....

What is your budget for clear?  The single use Spraymax 2K aerosol is around $20 on Amazon.

If you have a small compressor available, in addition to Klass Kote, there are a ton of 2k clear coat kits on the market that would likely suit your needs. 
The 2K varieties that are 4:1 mix are pretty darn thin right out of the can and should achieve a good finish.  If you search for 4:1 it should turn up a lot of results. 

I have used Speedokote SMR-100Q-M from Amazon for under 60 shipped.  It sprays out pretty nicely from my cheap Harbor Freight detail gun. 
I'm not a pro painter and as such, my experience is limited and should be questioned!   

Sherwin Williams Acme Finish-1, Eastwood, Summit, Jegs, UPol, Keystone and countless other offerings out there for reasonably budget friendly 2k clears that you can get in a quart kits for around $60 and gallon kits for around $100+/-ish.
 
There are also a lot of very high end, very pricey 2K clears out there too, if that is your need.

School me on the reason the tank vents face the way they do?

This was painted with that Speedokote clear.  I went from bare wood to what you see in less than 24 hours.  We had a pylon race last weekend and I built this plane in 2 evenings just for the event.  I applied the blue finish coats at 7pm, and we were racing the plane 15 hours later at 10am the next morning.  I did hang the plane for a few hours in a heated box to speed cure the finish.
Sealer/Basecoat was 2 coats of Eze-Kote water based poly.  I loaded the clear with copious amounts of blue pearl powder to achieve an opaque blue finish.  (If it looks like I barely sanded out the base and painted it in under 40 degree temps, on my patio, nearly in the dark...you would be correct!)  I can't advocate that rushed method, but it got the job done.

Doh!

Note that the plane flies clockwise. Vents face to the inboard side to keep the fuel from flinging out of the tank.

I've only seen Spraymax used. Worked perfect. Crystal clear. Over Rustoleum colors.

Thank you, gentlemen.