Grease spell confusion

[MarauderX]

Nuh uh.

Helpful quotes from the sites above?



Daniel
[edited because my quote from the site came out wonky]

I stand by my answer, as proven in your example, thanks.

 

[Pielorinho]

Actually, oxygen IS an issue. File down iron fine enough (so it has lots of surface area exposed to oxygen) and it *will* burn when exposed to a flame. That's what forms the "sparks" in sparklers. Spray olive oil at room temperature finely enough into the air (e.g. cooking spary onto an open gas fire!), and it will burn very well. Same with, say, molten candle wax (which will otherwise *not* burn by itself). Same with crisco.

Good point -- if a PC could figure out how to aerosolize the grease conjured by a grease spell, I'd allow them to let it burn. In fact, I might even add a spell into my game that would have the grease sprayed in aerosol form from the caster's hands and instantly ignited, doing 1d4 points/level of fire damage to anyone in a semicircular arc in front of the caster, with a reflex save for half. I'd let it be a first-level spell. Now if only I could think of a name for the spell....

Daniel

 

[Rel]

Good point -- if a PC could figure out how to aerosolize the grease conjured by a grease spell, I'd allow them to let it burn. In fact, I might even add a spell into my game that would have the grease sprayed in aerosol form from the caster's hands and instantly ignited, doing 1d4 points/level of fire damage to anyone in a semicircular arc in front of the caster, with a reflex save for half. I'd let it be a first-level spell. Now if only I could think of a name for the spell....

Daniel

Ooh! Ooh! I know:

Just another vote for the not-easy-to-ignite camp.

And while we're on the topic of oranges... did you know that the rind of the orange contains highly flammable aromatic oils?

How about Pielorinho's Flaming Aerosol of Aromatic Orange Oil (10 Radius - Semicircular)?

Next time my players find a certain sort of wand in my game, they're going to wonder why the command word is "PFAAOO!"

 

[Pielorinho]

How about Pielorinho's Flaming Aerosol Aromatic Orange Oil (10 Radius - Semicircular)?

Now, with fresh citrus aroma!

Daniel

 

[Rel]

Now, with fresh citrus aroma!

Daniel

Actually, Quasqueton's* next question will be:

My players want to interpret the Burning Hands spell as being ignited aromatic citrus oils and therefore giving the area of effect a smell of "fresh citrus aroma" instead of the normal smell of burnt human flesh. Are we doing this correctly?

To which I'll reply:

The Burning Hands spell is already quite powerful enough without adding any "fresh citrus aroma" effect as well. Adding a pleasant smell to the spell seems to go beyond the normal spell parameters and would push Burning Hands to a power level more akin to a 2nd level spell. This would be like giving them a free Prestidigitation with every casting of Burning Hands.

Too much power creep.

*I wish in no way to imply that Quasqueton asks frivilous questions without merit. I've met him in person and he is a very cool guy and I look forward to seeing him at the next NC Game Day and I wish Pielorhino could come too.

 

[Henry]

*Seconded Hue and Cry for Daniel to come visit the Game Day*

While I wouldn't have problem with letting a grease puddle burn being exposed to a fireball (and POSSIBLY a flaming sphere), I couldn't see Joe Adventurer applying a torch and setting it on fire. That's the point, isn't it? It would be implausible to me to allow it, and by the spell as written would be putting something in that clearly wasn't there.

So, for a house rule, that's fine, but I can't see a DM in, say, a tournament game logically adjudicating that grease (from any source) is highly flammable.

 

[maybeso]

Um, this is not true. The reason the paper cup does not ignite has nothing to do with heat transfer and everything to do with the amount of water the cup has absorbed.

NO, it's not. I have done this trick with a WAXED paper cup, very low absorption, and an propane torch. you can melt the wax off the outside of the cup, and the inside once the water gets above the melting point of the wax, but you can't burn the cup until you boil away the water, you can't get the paper to it's flash point. You can get the paper to scorch and brown a bit, that's it. The water is very good at moving heat away, because you can't get liquid water above 212F/100C without the huge state change cost to change it to steam and then the steam leaves the area you are trying to heat. It's all about heat transfer.

back on topic:

if a pint of oil does 1d3 for 2 rounds in the square you light it in (PHB pg 109 under Oil) then I doubt the thin layer of grease is going to do anything useful, even if you get it to burn.

 

[LokiDR]

Actually, oxygen IS an issue. File down iron fine enough (so it has lots of surface area exposed to oxygen) and it *will* burn when exposed to a flame. That's what forms the "sparks" in sparklers. Spray olive oil at room temperature finely enough into the air (e.g. cooking spary onto an open gas fire!), and it will burn very well. Same with, say, molten candle wax (which will otherwise *not* burn by itself). Same with crisco.

But a lump of iron, or candle wax, or crsico, or axle grease will typically *not* burn. It may sustain fire if there are other flammable materials in the area, but it will not burn by itself. Heck, some types of airplane fuel aren't even flammable in liquid form. But if you heat them up and/or aerosolize them...

So does flour. We aren't talking about powerders that burn. We are talking about fats. Crisco will light. Iron won't. Grease is flamable, iron isn't. And the point you are making doesn't really say iron burns, only that it oxydize. Powered substances that explode don't neccessarily burn.

Crude oil is rather flamable, has been known for a long time, and occurs naturally.

The point is NOT that trying this is a good idea. It is that, at some temperature, the grease will ignite. Casting grease on a large fire elemental should create a sudden flare. This might mean the elemental would burn away a grease spell, or perhaps leave firy footprints. Grease spell + tindertwig might be the same as grease alone, but that doesn't stop you from useing the spell as an improvised flare or other ingenious purpose. These are not written into the spell, but they fall within the realm of the spell.

 

[LokiDR]

NO, it's not. I have done this trick with a WAXED paper cup, very low absorption, and an propane torch. you can melt the wax off the outside of the cup, and the inside once the water gets above the melting point of the wax, but you can't burn the cup until you boil away the water, you can't get the paper to it's flash point. You can get the paper to scorch and brown a bit, that's it. The water is very good at moving heat away, because you can't get liquid water above 212F/100C without the huge state change cost to change it to steam and then the steam leaves the area you are trying to heat. It's all about heat transfer.

This is an old boy scout cooking tip. Rather funny to watch, but boils eggs well enough, so long as you keep the campfire ash out of the water.

And yes, it is a question of flash point. The water takes the heat and absorbs it. After more heating, the heat is used to vaporize the water. Boiled egg in cup on fire. Yum.

back on topic:

if a pint of oil does 1d3 for 2 rounds in the square you light it in (PHB pg 109 under Oil) then I doubt the thin layer of grease is going to do anything useful, even if you get it to burn.

How much area does that pint cover? How heavy is oil compared to "grease"? How long does it take "grease" to burn away compred to oil? How thick does grease have to be to cause you to slip? How hot does grease burn, compared to oil?

 

[MarauderX]

NO, it's not. I have done this trick with a WAXED paper cup, very low absorption, and an propane torch. you can melt the wax off the outside of the cup, and the inside once the water gets above the melting point of the wax, but you can't burn the cup until you boil away the water, you can't get the paper to it's flash point. You can get the paper to scorch and brown a bit, that's it. The water is very good at moving heat away, because you can't get liquid water above 212F/100C without the huge state change cost to change it to steam and then the steam leaves the area you are trying to heat. It's all about heat transfer.

Again, my point is that the cup does not catch fire because of it's absorptivity, and has nothing to do with heat transfer and everything to do with the properties of flammability of the contents. A paper cup holds water how? Once filled, water molecules soak into the fibers of the paper, and the paper expands slightly, sealing in water better than if it contracted. If you let the paper cup sit for hours you will see the cup leaking. No, it is not condensation, and you can try it with room temperature water.
What is happening with the cup under the bunsen burner then? The heat is being transferred to the water via conductance and radiance, yes; but by no means does this have anything to do with the flammability of the cup but the flammability of the water in the paper fibers, of which happens to be nil. If you boiled the water in the cup, the cup will still not ignite. If you sealed the cup and produced steam in the cup, the heat will drive the steam upwards until the bottom is dry enough for the fire to catch.

"Dude, you are so wrong! I saw it happen, man, I was there!"

That's great, I'm sure it did, and perhaps that's the logic of your teacher, but I'm glad I studied the mechanics of materials and heat transfer a little better than him/her. Next time, ask your teacher to fill a cheap plastic container (not heat resistant) with water and try the same trick. The water may prevent the plastic from getting hot for a little bit, but the plastic will certainly melt before the water boils. Why didn't the water absorb the heat then?

edit: Sorry, don't mean to hijack the thread, but I feel like I have to defend RL physics a bit.