Howw to apply weapon blanches on arrows

[Pulgoso]

I am going to play my first glass cannon (Zen Archer, indeed) and I dont know to apply weapons blanch on my arrows.

Quote:

These alchemical powders have a gritty consistency. When poured on a weapon and placed over a hot flame for a full round, they melt and form a temporary coating on the weapon. The blanching gives the weapon the ability to bypass one kind of material-based damage reduction, such as adamantine, cold iron, or silver. The blanching remains effective until the weapon makes a successful attack. Each dose of blanching can coat one weapon or up to 10 pieces of ammunition. Only one kind of weapon blanch can be on a weapon at one time, though a weapon made of one special material (such as adamantine) can have a different material blanch (such as silver), and counts as both materials for the first successful hit.

emphasys mine.

The question are
1. Do i need a forge or some special tipe of great fire? or I can apply the weapon blanch with a bonfire, torch or something similar
2. the statement says "temporary" How much time is it? until arrow is used? I guess the answer is yes and temporary only means that it is nos permanent, But i would like to have confirmation.

Thank in advance

[RealAlchemy]

Temporary in this case means it lasts for one successful hit. This matters for you if you buy durable arrows.

[Renata Maclean]

"The blanching remains effective until the weapon makes a successful attack"
Pretty clear there, it lasts indefinitely until it hits with an attack

Not sure what qualifies as a "hot flame", but I would guess any flame large/hot enough to deal lethal fire damage would be sufficient

[Matthew Downie]

The phrase "hot flame" is ambiguous. Googling it suggests it is mainly associated with barbecue restaurants. So there's no particular reason to assume you need to go to a blacksmith's forge.