I repainted my Wayfarer last winter – spring ( and into summer), I found it near impossible to eliminate all chances of getting dust and insects on drying paint. What I did do though, and bear in mind I was using my single garage plus a garden gazeebo, was this. I used a large fan to blow dust out of the garage whilst blowing the walls and any pipe work and shelving with a vacum cleaner on blow. This seemed to get rid of most if not all the dust that might want to turn my painted surface into cheap looking sand paper. A thorough dusting down of surfaces is also helpful. You will find that the wind can make your tent bellow in and out which can also stir up dust and dead bugs. I would recommend you have adequate ventiliation when painting, which again brings it own problems with dust and flying insects. You might think I will paint it before bugs appear but the temperature is also important so you might have to paint later in the spring – summer to avoid issues with the paint drying, blooming ETC. I hope this helps and I do not come across as too negative I just know how frustrating it can be from my experience, to do it with out the paint shop set up the pro’s use.