Pine sliding doors sliding channel question

[joncooper27]

I have an old Pantry cupboard that I want to renovate and paint eggshell paint. I have 2 questions
I will give it all a good sand but what primer should I use and eggshell paint for it to stick and a wow finish?
The runners the sliding doors sit in are just a wooden channel and they don’t slide that well. Any ideas to improve the sliding part?

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