Paint help

[Matt]

I've been smoothing my grill. Have fiberglassed. Then fillered. 
Now painting, the only problem I'm having is when I'm trying to sand back the fresh paint, it just softens and turns weird. 

How do I stop this? I've tried wet sanding, different grades, a sander. All of it makes the paint weird. I thought it might be because the paint isn't dry enough, so left it for 12 hours and it's the same. 
I literally spent 10 hours yesterday trying different methods to fix this.
But it's really pissing me off now. The shape and everything is perfect. Just the paint is shit

[Pug0BZ3011]

If it's cellulose you will need more that 12 hours to dry, after 12 hours you'll find it's not tacky but will be soft underneath so try leaving it about 3 days

Edit- Heat will also help

[Dum-Dum]

Give it longer to dry, preferably somewhere warm.

[P-Courty]

Same as above definatly give it longer to set.

[Matt]

Yep it was down to me being extremely impatient. Just left it alone and it's dried again over night and now rock solid, time to crack on cheers guys