Some context for the question in the title: After years of fixing stuff around the house, I've developed a chronic form of sinusitis - the minimal amount of dust is enough to set me off. I do use a serious protection mask when working, but even the dust that remains in the air or the settles on the mask/face will affect me.
So I'm figuring out ways to do dust-free DIY.
Next up in the TODO list are a couple of wooden doors and window frames. I would like to give them a new layer of primer + lacquer on top of old (yellowish) but good state lacquer.
The product instructions insist on sanding after the primer and between layer of lacquer.
Why is that necessary? and what would be the consequences of not doing so? Are there any alternatives?