Newbie help with alcohol stove cooking

[wistuart]

I usually use a gas canister stove but recently decided to see how alcohol faired having read so many positive things about it.

I've got a Lidls trangia copy burner and an Alpkit Mytimug so I rigged up a small stand and set about heating 500mls of water. It took over 20 minutes to come to a boil (ambient air temperature was 5 degrees with a slight breeze) which is really not practical for me. I tried again with 300ml as that's my standard cup size and by twenty minutes it hadn't even started to boil so I gave up. I had a small windshield and the fuel was producing what looked like nice, healthy blue jets of flame so I'm really not sure where I'm going wrong. I did wonder of titanium is maybe not the best of materials for this application due to it's rapid heat transfer and that might explain why the smaller volume of water appeared to take longer to heat.

I'm happy to try different burner/pot configurations if needs be but I'd really like to have a better understanding as to why my initial attempt was so poor. I've read some of the alcohol stove threads here and have browsed the Zen site but so far I'm not really any the wiser as to where I might have gone wrong.

 

[sapper1]

Did you put a lid on your pot?This is where most of the heat is lost.

 

[wistuart]

Hi. Yes, I used a lid and only lifted it for a second or two every 5 minutes to check progress. I also tried a couple of different heights between burner and pot but was not able to improve on approx 20 minutes. The fuel was regular purple meths out a hardware store.

 

[Shambling Shaman]

Was the burner on the ground? I have found that slightly raised of the ground works better, a good wind shield is a must but at the same time oxygen is needed fine balance.

 

[Dean from ExtremeGB]

You weren't in one of these "freak snowstorms" by any chance?

 

[wistuart]

Burner was off the ground (sitting on top of an aluminium step stool for convenience).

No snowstorm. Conditions were mild for this time of year. 5 degrees and mild breeze. I had a windshield that provided adequate protection for the stove such that the flame got very little buffetting. The pot was not protected by the shield to any great extent so windchill on the outer surface might have been a factor I guess.

I've read numerous reports of people being able to boil similar quantities of water in around 5 minutes. Logically, it can only be the fuel, the cooker, the vessel or me being a numpty.

The fuel is as bog standard as it comes so I'll discount that for now. The cooker looked to be running properly and is a traditional design. The pot is very popular and I've read no negative reports on it and, now that I think about it, I also tried a similar sized aluminum pot without any improvement. Starting to look like it might be me, but how hard can it really be to boil a pint of water?

 

[Shambling Shaman]

Burner was off the ground (sitting on top of an aluminium step stool for convenience).

No snowstorm. Conditions were mild for this time of year. 5 degrees and mild breeze. I had a windshield that provided adequate protection for the stove such that the flame got very little buffetting. The pot was not protected by the shield to any great extent so windchill on the outer surface might have been a factor I guess.

I've read numerous reports of people being able to boil similar quantities of water in around 5 minutes. Logically, it can only be the fuel, the cooker, the vessel or me being a numpty.

The fuel is as bog standard as it comes so I'll discount that for now. The cooker looked to be running properly and is a traditional design. The pot is very popular and I've read no negative reports on it and, now that I think about it, I also tried a similar sized aluminum pot without any improvement. Starting to look like it might be me, but how hard can it really be to boil a pint of water?

Ok you need a bench mark test, do it in door optimal conditions.

 

[Urban_Dreamer]

The pot was not protected by the shield to any great extent so windchill on the outer surface might have been a factor I guess.

That's what I would guess. I've never used the burner without it's "stove" which goes around the pot.
There's a video of one being used here.
http://www.videojug.com/film/how-to-use-a-trangia-camping-stove
Note, I have not watched it fully and can't comment upon the "how to use" bit, but it does show what I'm talking about.

I was impressed with how simple and effective my cheap lidl copy was.

 

[bikething]

...(sitting on top of an aluminium step stool for convenience)....

The aluminium might be taking heat away from the burner like a heatsink - try sitting it on top of a bit of corrugated card or wood for insulation ?

Also shielding the pot will help - the walls of the pot above the water level will act like a radiator as they have very little thermal mass...

 

[rik_uk3]

Stuart(?) Have you a picture you can show me. The Lidl burner is not bad at all and you should have much better boil times. You will loose heat from Titanium but not enough to give your boil times.

 

[Shambling Shaman]

Stuart(?) Have you a picture you can show me. The Lidl burner is not bad at all and you should have much better boil times. You will loose heat from Titanium but not enough to give your boil times.

Agreed, this is why I would re do the test in doors room temp that should rule out a bad burner or fuel?

 

[squantrill]

Using a lid windshield and hot burning spirit should be fine even in the colder months..

make sure you wrapp the billy or cup with the wind shield (ala jetboil) I usually boil half a crusader cup on a cold windy day in nno more than 8 to 9 mins

I have found sitting between the wind and the burner also helps as the wind doest take the heat from the top of the cup.. maybe putting a rucksack of something in the path may help..

Make sure also that the burner is running before you start boiling most meths burners take a while to get up to heat!!

Simon

Today I tried it in anger.. Bushbuddy upturned simmr ring with burner on top, crusader have full plus plastic top (must get a metal one!!) wrap th head sheild around the cup and allow only the handle to stick out Time to boil exactly 5 mins!! that for me is a record!!

 

[wistuart]

I made some really good progress over the weekend. As per advice I moved inside for testing. To get a baseline I set up the burner in the original trangia-style stand that came with it and, once the burner had bloomed, put on the Mytimug with 500Ml of cold water. This came to full boil in 15 mins. I then repeated the test with 250ml which took 7.5 mins which tends to disprove the radiator effect theory, though I plan to rerun this test outside once there's a reasonable breeze.

Next I tried 250ml using my own home-made pot stand. The stand is a simple affair made from a couple of sections of beer can. It encloses about 5/6th of the circumference of the burner, sets the pot about 3 cm above and has, or so I thought, enough holes punched in the side to provide sufficient air for the flame. Time to boil with this configuration was a dismal 20 minutes.

I noted that my homemade effort had the vessel much closer to the top of the burner than the proprietry stand so I made a new beercan stand but made it taller and added 50% more ventilation holes. The difference was staggering. I had though the stove was burning away as it should be in my mark1 stand but clearly it was not as the veritable furnace churning away in mark2 showed me what output from the burner should look like.

A few more tests later and I settled on beercan stand Mk4 which returned a repeated boil time of 6 mins (+/- a few seconds). I was quite surprised that my own homemade job was actually quicker than the trangia stand so I ran another test boil on it and got the same 7.5mins as I had before. Curious. I believe what's happening is the beercan stand is actually serving to retain heat around the burner and increasing the internal pressure that pushes fuel out the jets.

Sorry if this is an awful long-winded post for what is probably a fairly trivial matter but I found it quite interesting working through the process and was really pleased with the results.

Thanks to all for the variious suggestions.

 

[Shambling Shaman]

Looks like you go it sorted,