Home-made Fire Gel

[match]

Had a weekend away camping in a bothy a few weeks ago, and when we got there there was a small cast-iron stove for heat, but most of the wood had been left out in the open, and was very damp - hence it was going to be difficult to get a fire going.

However, one of the guys who was staying with me taught me a very nice trick for starting fires - that is how to make a fire gel from household products.

He basically found a bottle of extra-strong washing up liquid that someone had left, and some vegetable oil, which he had with for cooking. He mixed the two together (not sure what quantities - maybe 50%/50%?) - and then dipped torn strips of cotton in this (although he said paper would work equally well. This worked as an excellent firelighter and burned foir long enough to provide a good heat to get he wood to start burning - and gave us all a warm night!

Now I thought this would be a handy tip to tell people about - the guy said that you needed pretty strong soap for it to work. I could take a vague guess at why this works, but I'm hoping there are enough people here of a chemical bent who can tell me how it works?

 

[bambodoggy]

The soap is just used as a Gelling agent which helps the oil burn hotter and longer and also stick to things.
Napalm is basically Petrol mixed with a gelling agent and we all know how well that burns.
When in the army I was taught to make home-made napalm by shaving a bar of soap into a container of petrol (a petrol bomb if you like) but with much nastier effects.

Not sure of the chemestry but it sure does work! ):

 

[Andy]

there was a thing on here some time ago about making your own gelled alcohol. I can't remember the chemistry behind it either

 

[match]

The soap is just used as a Gelling agent which helps the oil burn hotter and longer and also stick to things.

I'm thinking there must be some chemical action involved here as well. I just tried mixing some cheap washing up liquid with some vegetable oil and putting a bit of paper in it as a wick - it burned, but only very slowly - not the very hot fire we had from the strong stuff in that bothy... time to email my chemist friend...

 

[Realgar]

For ethanol, the gelling agent is a saturated solution of calcium acetate. This has the added advantage of colouring the flame so you can see the blasted thing. I'm not sure what's going on with the acetate at it didn't seem to work with straight methanol as an alternative alcohol.

I'm betting cheap washing up liquid just has too much water in it.

Is biodiesel any good as a stove fuel or fire lighter? I fancied making some just for the hell of it.
Realgar

 

[ESpy]

What you need is a handy pyromaniac. Now, where would we find one of them?

http://www.bushcraftuk.net/community/showthread.php?t=774

I'm told that biodiesel is an excellent cleaner, but I wouldn't expect it to burn well without some assistance - either using the oil/water atomising trick, or a multi-fuel type stove. I think I'd prefer to use biodiesel than regular in my Primus, but I'd double-check materials compatibility.

The cotton would give a good wick, bumping up the surface are exposed to the air (hence more oxygen), I'll have a look & a think about the w/up liquid. The thing about napalm is that the fuel component is highly flammable anyway, which veg oil isn't. I *think* this is a physical chemistry issue, rather than a reaction per se, but I'll have a look. It is possible that the water content of the strong w/up liquid is just high enough to cause atomising of the fuel at heat?

 

[Gary]

The soap is just used as a Gelling agent which helps the oil burn hotter and longer and also stick to things.
Napalm is basically Petrol mixed with a gelling agent and we all know how well that burns.
When in the army I was taught to make home-made napalm by shaving a bar of soap into a container of petrol (a petrol bomb if you like) but with much nastier effects.

Not sure of the chemestry but it sure does work! ):

We were taught a similar thing but with elastic bands - a napalm molatov cocktail - naughty but nice!

 

[Stuart]

guys petrol is flammable anyway, adding additives only to make it napalm is not bushcraft.

no more about napalm please.

 

[EdS]

RE biodiesel

If it is the stuff that you buy in garages it is a 5% Biodiesel to 95% mineral diesel mix.

!00% biodiesl can be got from:

www.bio-power.co.uk

 

[ESpy]

Isn't that generally just termed "green diesel" or some such marketing nonsense? I'd like to use some 100% biodiesel, but the nearest mixed stuff is about 45 miles away from me - which kind of defeats the object in the first place.

I think we had something around on biodiesel synthesis?

 

[Roving Rich]

There are different types of biodiesel, Bio powers is basically a mix of Veg oil and white spirit. The origional Bio diesel "cracked" the oil molecule using caustic soda, and split off the Glycerine. I wouldn't put this in my stove as it has a bad habit of eating pure rubber.
It is caustic by nature, so yes is very good for cleaning.
Now I'm not much of a chemist, but one of the few uses of Glycerine is making soap. This is also the bit that makes vege oil too thick to run through your car as standard. So I'm guessing its the Glycerine that in the washing up liquid that makes the gel.
I'd be interseted to learn more, as its very handy stuff for priming primus type stoves.
Cheer
Rich

 

[bambodoggy]

Yer, sorry everyone....Stuart is quite right, napalm and bushcraft aren't a natural partnership.... didn't mean to offend just thought that might be why the original oil/washing up thing that started the thread worked hence I didn't go into details.... :icon_redf

 

[ESpy]

There are different types of biodiesel, Bio powers is basically a mix of Veg oil and white spirit.

That's the stuff that leaves the delightfully unpleasant fatty triglycerides in the fuel, which can knacker your injectors.

The origional Bio diesel "cracked" the oil molecule using caustic soda, and split off the Glycerine. I wouldn't put this in my stove as it has a bad habit of eating pure rubber.

Well, the caustic soda is a catalyst, and shouldn't be present in the final fuel... Some gubbins about the process:
http://www.cyberlipid.org/glycer/biodiesel.htm

Caustic soda + aluminium makes for a pretty mess too... There was something about degradation of rubber seals, but I can't remember what offhand. Also reported occasionally - manky engines get all of the junk cleaned out of the fuel system, ending up in the injectors... :shock:

Now I'm not much of a chemist, but one of the few uses of Glycerine is making soap. This is also the bit that makes vege oil too thick to run through your car as standard. So I'm guessing its the Glycerine that in the washing up liquid that makes the gel.

Some of the best soap, no less! The soap would allow the oil to emulsify.

I'd be interseted to learn more, as its very handy stuff for priming primus type stoves.

Working on it

 

[EdS]

Glycerine is used in soap manufacture but not washing up liquid - its a detergent