Zinsser over Mahogany paint

[Ukowen38]

Hi all my doors & skirting boards are painted in mahogany. I was planning on sand them down lightly. Then putting Zinsser 123 on them. Then a finish coat of satin wood 1 or 2 coats. Do i need to put a undercoat on aswell or is Zinsser ok.?

 

[piglet11]

Zinnser 123 is really a stain blocker or a key between oil based paints and water based paints.
You don't say what you are planning to put on top other than satin. Oil based -not recommended - colour - white?
Zinnser is good, but you do need to provide a good key. I always rub down with a good bonded abrasive and use meths as the lubricant. Clean off with a cloth and meths.
For such a dark colour, I would put on two to three coats of Zinnser and two coats of top coat. No traditional undercoat needed.
If you use meths, keep the windows open or you will have an early Happy Hour.