Not trying to argue, just learn.
Recently I just painted a 10x10x8 wood storage shed. I also just put a bead board ceiling on my 50x10 foot patio ceiling and reprinted the whole thing. I used a Wagner airless sprayer on both products. Even with masking and drop cloths, plus using a large paint shield were I could. It was much easier, much less messy and much quicker then the times I've painted with rollers. It also did an excellent job. I've read other comments about "you should roll". I must be missing something because I think rolling is messier, takes longer and does not cover as evenly as taking your time with the sprayer. I also don't understand your "lost paint" comment? /Steve
When you paint something, you are trying to achieve 3 different things:
1. get the paint from the container to the surface
2. "key in" or adhere to the surface well (at the microscopic level)
3. finish the surface of the paint so it looks good (cosmetic)
Sometimes you can achieve good enough results with one movement, sometimes it takes more.
If you dip your brush in the paint can, wipe the brush firmly into the surface with a good quality brush, you can achieve all 3.
Keep in mind that sprayer, roller and brush give 3 different finishes. The difference might make a difference to you, or it might not, depending on what you're doing. I can assure you if your car was painted with a brush or roller, you would not be happy!
If a surface is very glossy, paint doesn't stick well. If you lightly sand that surface, what you're doing is making microscopic hills, valleys, and crannies. When paint goes into these, it dries and gets "locked" into place and is a much tougher surface. However a sprayer doesn't push paint as firmly in as a brush would.
On the other hand, a sprayer moves more paint from the container to the surface MUCH faster than a brush ever could.
That's why you see these combinations of like spraying, then back brushing, or spraying and backrollling. It helps even out the finish, put a consistent texture on the finish, and "key in" the paint to make it adhere the best. Moving paint from the container to the surface with a brush, or even a roller, is EXTREMELY time consuming when you add it all up. It might not make much difference to you with a 4 hour weekend project, but to a pro who does thousands of hours of work, it can make a big difference.
If your spray job has lasted years, then it has adhered well enough. There is no doubt if you had back brushed it, it would have adhered slightly better. But you might not have needed it any better.
