Is the coating for the first swing of the weapon? If so will there be a Potion Tirgger (like poison trigger)?
Actually, that’s not correct.Except where otherwise specified, it works like a poison coating. So you can swing it until it makes contact with something, you can store it in a Poison Cache, you can trigger it with a Poison Trigger, etc.
That's not what @Polare said here: https://alliancelarp.com/forum/threads/potion-coating-clarifications.38087/Actually, that’s not correct.
A Potion Coating does not turn a potion into a weapon coating. It allows a potion to be applied in the same manner, which is why it works with Poison Cache/Trigger, but it is functionally different.
The next swing with that weapon will function as a spellstrike, not as a poison-coated weapon. It will burn the potion. The only way to prevent that is with Poison trigger, which will allow you to choose when it’s used.
Every time she swings, she can pick any single potion/poison loaded in (or none at all if she doesn't want to use one on that swing). Coatings last once activated until they land, but you can't activate one, then "pull it back in" if you want to stop calling it (unless you are willing to lose the coating).
Same as poisons. Normally, one, which will be used the next time you swing it. If you've got Poison Caches on your weapon, more of them, and you decide what order they come out. If you've got a Poison Trigger on it, you also decide when they come out.How many potions can be coated on one weapon?
The way that poisons/potions work is that once it is active on the weapon, you can only swing the poison/potion call. You can swing that call as many times as you like until it makes contact with something, whether it is a valid target or not. Unless you completely miss your opponent, there's usually only one swing of it. Though if you swing a different call with that weapon for any reason, the coating is also used up then.The only reason you can trigger it when you want is with Poison Trigger (see what I did there).
Back to my first question though, will a Potion Coating via the ritual make it for the next swing (as in the example of the character pulling out the dagger to use when needed).
Potion Coating refers explicitly to Earth Potions. What's that supposed to mean?The Potion Coating Ritual allows Earth Potions to be applied to the target weapon in exactly the same manner as a contact poison (i.e. requiring Herbal Lore). These potions are delivered as “Spell Strike <Effect>” for example, “Spell Strike Destruction” (for a Destruction Potion) or “20 Spell Strike Healing” (for a 4th level Cure Wounds Potion); unlike Poisons, the character’s normal weapon damage and effect are entirely replaced when utilizing loaded Potions. This Ritual may be combined with other Rituals as appropriate.