I was fixing a small imperfection on the top of the door I painted the day before. It was really to small to use my mini gun on so I used my airbrush. (Like I’ve done in the past to fix a few rock chips).
Apparently I didn’t add enough hardener in the DC3000. The cup on the airbrush holds less than an ounce. I mixed the clear and hardener (4:1 ratio) in a separate container and poured in into the airbrush cup.
The DC3000 takes about 3 hours to air dry. It’s been 2 day and it’s still slightly tacky.
Should I just wipe the spot with some lacquer thinner and start over or spray on a little hardener?
Thanks in advance.

If it's not hardened by now it should come off with thinners on a cloth. Watch that your earlier work doesn't soften with the thinners. You'll have to re-do the whole repair, of course.

Unless you have very accurate scales, mixing small amounts of clear can be problematic. The usual solution is mix a slightly larger quantity in a mixing cup which has markings for the different mixes.

Thanks, just wiped it off using lacquer thinner on a rag. I was trying to measure what I needed using an eye dropper as the amount I needed was very small. I’ll use a measuring cup this time.