As part of the November A-Spell-A-Day challenge here is a few Duration: Fire Spells. This one may be useful for craftsmen or to direct the flow of a normal fire.
Direct the Heat of Fire
Rego Ignem 20, R: Voice, D: Fire, T: Individual, Faerie
The caster dictates an exact direction to focus the heat of the targeted fire. The fire itself does not move unless it is able to also expand by burning materials in the dictated direction. The caster may change the direction by concentrating.
(Base 3, +2 Voice, +3 Fire)
Find this spell and hundreds more for Ars Magica in my grimoire.