Jan 18, 2012 at 1:43 am #1284289
This is an offshoot of the thread about adding fins to a Rockstar. That thread was getting long and really theory heavy.
The results are in!
Parameters of my test:
Fosters pot. Same windscreen w/ built in pot stand, and same alcohol stove. All times and temps are the average of three runs. 16oz of tap water was measured out with a measuring cup for each run. Temps were monitored using a calibrated Fluke 87 V multimeter.
Unaltered fosters – 23g (.8oz)
Starting temp – 61.1*F
Time to 200*F – 8:08
Black Paint Fosters – not weighed
Starting temp – 61.0*F
Time to 200*F – 7:30
Paint + fins fosters – 26g (.9oz)
Starting temp – 61.3*F
Time to 200*F – 6:12
For a scant 3g penalty, you save almost 2 minutes on your boil times if you paint the bottom of your pot black and add fins!
Fins were made from aluminum foil tape roughly 1in. Square. I did 18 at the very bottom of the pot and 8 midway up the pot near the top of the water line.
I believe the shorter times would correlate to less fuel consumed. However, I did not measure fuel consumption, as I did not think I could do that accurately do to the veriations in the amount of time it would take me to remove a hot pot and put out the stove.Jan 18, 2012 at 6:58 am #1826139
Well done, nick. I assume the fins are flexible and lay flat against the pot for packing?Jan 18, 2012 at 8:27 am #1826170
Daryl and DarylParticipant
@lyrad1Locale: Pacific Northwest, USA, Earth
Thanks for the info.
I can't resist implementing this idea. Good payoff in both weight and effort.
DarylJan 18, 2012 at 8:39 am #1826175
Great job. Thanks for conducting the tests and posting the results. A little data is always better than a lot of theories!
Assuming a constant alcohol burn rate, you've saved 24% of your fuel usage. Or about 3 grams of fuel per pint. You come out even on your first pint boiled and ahead thereafter. Very nice!Jan 18, 2012 at 8:47 am #1826183
@jamesdmarcoLocale: Finger Lakes
Good Deal! And it is surely worth the effort!
Thanks!!!Jan 18, 2012 at 9:22 am #1826207
Here's an offer:
PM me your US snail mail address and I'll throw some of that aluminum tape in an envelope and send it to you. I always have a few rolls around for various neferious purposes, but rather than everyone spend $12 for a 30' roll, I can send you two 9-inch pieces which is more than I used on a 6" diameter pot.
Suggestion: leave the wax paper backing on as long as possible: as you cut it, peel it back a little to start the first corner, etc. The sticky side is REALLY sticky.
I'll also consider overseas hardship cases as well (i.e. you just can't find this stuff we keep talking about being in every Home Depot in the USA).
You're on your own for the spray paint.
Editted to add: So Alaska CAN export something besides salmon, oil, and wacky TV shows, after all. And if you live even 2 miles from a hardware store, you'll save more gas than my 44 cent stamp, burn LESS ALCOHOL!, and USPS sure needs the business.Jan 18, 2012 at 9:58 am #1826224
Nice work, Nick.
One way to check that the stove isn't burning hotter (which is a possibility) is to measure a fixed fuel volume, and measure boil time and total burn time.
If the total burn time is unchanged, then the black paint isn't changing the behaviour of the stove, and you're getting a genuine improvement in efficiency.
As for David's kind offer, fortunately, flue tape is one thing we do seem to be able to find in the UK, unlike the near-mythical 'aluminium flashing' from Home Depot…Jan 18, 2012 at 9:59 am #1826225
@namaniacLocale: SoCal-High Desert
Would it be possible to post some pics of the finished product?
I read the original thread but i am unclear of the final design you used….and id like to try it out myself!Jan 18, 2012 at 10:50 am #1826249
+1 on the pics. I assumed my stove would melt thin aluminum like that. Love to see how you did it.Jan 18, 2012 at 4:02 pm #1826391
Ok, here's some pics guys. Sorry about the poor camera phone quality. My pot won't win any beauty contests but it worked. I had too much time invested to worry about aesthetics on this one.
I found it was easier to rip strips out of the foil tape and do the fins individually rather than folding fins out of one long strip like I did with my last stove. I was also able to make the fins a little smaller, instead of using the full 1.5"? width of the tape.
Just make sure you press the fins onto the can really good, before you use it the first time, as any exposed adhesive will be rendered useless if exposed to the heat. One nice thing, is that you can replace individual fins this way if over time they fall/break off, melt, etc.
And, yes, the fins do fold for storage. My last pot, I didn't even store in anything, just threw it in a relatively safe spot in my pack.
As the other thread was getting into, fin configuration may make a difference, so feel free to mess with that. And feel free to check on fuel consumption, but personally, I'm sick of boiling water for now…
The "insert photo" wasn't working for me, sorry.
P.S. That's a generous offer David!Jan 18, 2012 at 6:44 pm #1826464
What do they flash roofs with in the UK?
Have you tested any to see when the tape starts melting? Someone has said the adhesive is flammable.
Seems like I recall another thread where someone used AL tape in this manner. A-ha, it was me. D'oh! Found it. Never have tested it yet so thanks, Nick!
Here's another video that may give y'all more ideas.Jan 18, 2012 at 7:06 pm #1826471
I like that pot idea in the video! I wonder how much weight it adds though, and how it compares to say a caldera cone.
P.S. If anyone knows how to embed images from the internet on this forum, I would love to know…Jan 18, 2012 at 7:09 pm #1826473
Nick: I like the bananas in the pictures. I'm not sure why, but I like them a lot.
Seth and Todd's aluminum tape went out in today's mail.
>"but personally, I'm sick of boiling water for now…"
Nick's wife: "No, I don't want ANOTHER pot of tea!"Jan 18, 2012 at 7:31 pm #1826482
Well done Nick. I will try this on my potJan 18, 2012 at 7:32 pm #1826483
I'd be interested in seeing the data for each run (to see how much variation the is)Jan 18, 2012 at 7:58 pm #1826497
You must use HTML code for online images. Make sure you use the width tag. I think 550 is the max that works here.
Edit: Yep, 550 is the max to fit the forum width. If your pic isn't that wide you don't need the tag.
The above pic is done with:
img src="http://farm8.staticflickr.com/7151/6722780299_d155b3b06a_z.jpg" width="250"
except you need to add left and right angle brackets to be processed as HTML.Jan 18, 2012 at 11:40 pm #1826555
@ David: Well you know, as a professional camera phone photographer, it's all in the background…
Nick's wife: "No, I don't want ANOTHER pot of tea!"
Nick: "Drink it. FOR SCIENCE!"
@ Jim: I'll see if I can find my data now that I've cleaned up… If I remember correctly though, I believe there was up to 1 min. discrepancy. For example, I seem to remember the fastest time for the paint/fin pot being 5:33 and the longest being 6:27. I seem to remember it being similar for all cases, but I'll try to find my data tonight. Probably would be a bit more stable if I used something like esbit, and would be easier to monitor fuel consumption.
@ Michael: Thanks! I fixed my last post so it's easy for viewers.
Also, I didn't test for tape melt. I'm sure it wouldn't take much if it wasn't attached to the pot, or if the fins stuck out too far. I guess I just figured if mine didn't melt after 9 minutes, it wasn't worth worrying about. Also, it's not an integral part of your pot, so if they melt/break/unglue it will just take you a little longer to boil at worst, and you can fix them when you get home.Jan 19, 2012 at 5:00 am #1826581
> What do they flash roofs with in the UK?
Michael, the most common material is still lead, or a lead-alike, and it's thick. Either that or bitumenised felt or self-adhesive polymer tapes.
Here's a search on a popular UK builder's merchant's website. The only aluminium flashing comes with a self-adhesive buytl backing.
It's odd how different construction materials are used around the world, even in countries with similar levels of technology and materials.
> Nick: I like the bananas in the pictures. I'm not sure why, but I like them a lot.
Being a bear of little brain, I think I prefer the honey…Jan 19, 2012 at 5:04 am #1826582
I was more concerned about whether there may be anything nasty released if it burned. I'd guess not since it's used inside homes though nowhere near the temps or direct flame that should cause it to burn or melt. I also figured it might leave a sticky mess on the pot. Not as much an issue if you keep it in a sack. I presume you would recommend that to keep the fins from tearing off even if folded over?
As you found out, the Insert Image button is only for those pics on your PC or those you have already uploaded to the site. Anything else needs the HTML img tag.Jan 19, 2012 at 8:44 am #1826650
Are you using black barbecue spray paint or something else?Jan 19, 2012 at 12:06 pm #1826754
"If I remember correctly though, I believe there was up to 1 min. discrepancy. For example, I seem to remember the fastest time for the paint/fin pot being 5:33 and the longest being 6:27. I seem to remember it being similar for all cases, but I'll try to find my data tonight. Probably would be a bit more stable if I used something like esbit, and would be easier to monitor fuel consumption."
I've noticed the same thing when doing alky stove tests. I was getting +/- 30sec boil times when doing multiple tests with apparently identical setups. I think I isolated the missing variable though- the temperature of the surface the stove was sitting on. It apparently have a significant affect on the rate of fuel vaporization. See this thread for detailed information-
BMJan 19, 2012 at 9:31 pm #1827026
@coreyfmillerLocale: Eastern Canada
My cook set is an Ikea wood stove with an MSR titanium kettle. Would it be worth it for me to add some fins to the kettle? The bottom is black from being burnt, I assume this is just as good as paint but I could be wrong on this point as well.
I can paint and add fins. With the wood I've never really cared much about efficiency but its something to think about.Jan 19, 2012 at 9:50 pm #1827032
I haven't tested wood smoke versus black paint but (1) I'd expect them to be similar in performance and (2) whatever the pot color underneth, the outer layer will soon be wood smoke and it's the outer layer that determines "emissivity" or its behavior in absorbing and emitting radiant energy. So no need to paint for a wood stove.
Fins would help just like they do in a gas flame, but as you say, you're not so concerned about grams of fuel used because you don't have to carry it with you. But fins add a bit of weight and bulk that you do have to carry, so I'd be hesitant to bother with a wood stove. There are upsides and downsides of wood. These are some of the upsides.Jan 20, 2012 at 1:16 am #1827099
@ Kevin: Winnie the Pooh reference for the WIN!
@ Michael: To sack or not to sack, that is the question. It's up to you I suppose. I don't bother with one, as my gear doesn't move around much once it's all packed up. So far I haven't had any problems with fins tearing off. Just be sure to wipe any soot off the bottom of the pot if you do go sack-less.
@ Craig: BBQ paint should work, but I think mine is some kind of high temp engine block spray paint from Lowes.
Here are those individual test numbers:
Round 1 – Starting temp: 61.3// Time to 200*F: 8:54// Time to 212*F: 9:55
Round 2 – Starting temp: 60.8// Time to 200*F: 7:29// Time to 212*F: 8:29
Round 3 – Starting temp: 61.1// Time to 200*F: 8:01// Time to 212*F: 8:58
(Couldn't find the paper for the black paint only tests, sorry.)
Paint + Fins:
Round 1 – Starting temp: 61.1// Time to 200*F: 6:27// Time to 212*F: 7:13
Round 2 – Starting temp: 61.5// Time to 200*F: 6:36// Time to 212*F: 7:25
Round 3 – Starting temp: 61.6// Time to 200*F: 5:33// Time to 212*F: 6:20Jan 20, 2012 at 6:19 pm #1827465
@geokiteLocale: Southern California
Grill paint doesn't survive the heat of esbit. The paint ends up looking nasty, and is quite sticky. Sticks the pot to the inside of a cozy.
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