View Full Version : Paiting Your Cookpot Black
Footslogger
07-24-2006, 08:37
A while back there was some talk of improving the performance of cookpots by painting them black.
Just wondering how many of you have done that or bought one that is black and how it is working.
Last but not least ...to those who HAVE painted their cookpots, what type of paint did you use. I'm thinking of giving it a try and am leaning towards using that high heat black paint sold for gas grills. Anyone tried that ??
'Slogger
SGT Rock
07-24-2006, 08:47
I cook over campfires and alcohol so I just let the campfire do the work of making my pot black. I don't know if it helps much. I used that grill paint on stove stands, it does fine in the heat.
Footslogger
07-24-2006, 08:57
I cook over campfires and alcohol so I just let the campfire do the work of making my pot black. I don't know if it helps much. I used that grill paint on stove stands, it does fine in the heat.
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Thanks Rock. I have the Evernew Ti (0.9 Liter) post. This past weekend the wife and I went up in the mountains near Laramie. I cooked with alcohol and she used her pocket rocket and a 1.3 Liter Ti pot . She seemed to get a good rolling boil sooner but she waited until that point to put in her food (tortolinni). I wait until I see bubblage at the bottom of the pot and then throw in my stuff.
By the time my meal is at a full boil (where I out the stove and let it sit for a while before eating) she was pouring off the excess water in her pot and getting ready to eat. Bottom line is that we both used about the same amount of water and ended up eating at roughly the same time.
Guess I got a bit off topic with the whole food thing but as I was cooking my dinner I got to thinking about the black paint on the cookpot (my cookpot is currently unpainted) and wrote myself a note about following up after I got home. I rarely, if ever, cook over open fire any more and my Trangia does not cause blackening so ...if I want to try it out I'm gonna have to get out the paint.
'Slogger
SGT Rock
07-24-2006, 08:58
I have that same pot. Nice
Well maybe there is something too having black pots.
I paint my pots black. I paint ALL my hiking pots black. I don't know if it helps, I think it does, at least it seems to. Maybe cuts boil time by a few seconds. Never did any tests.
But what I do know is: most engine paints get slick(er) when heated, (prolly to make your engine look shiny) causing your pot to gracefully slide off the stand. SOOOOO, use grill paint, it stays flat at any heat my stoves can / could produce. Stoves I have used: Coleman apex II, MSR Dragonfly, Esbit, Alcohol.
I have even painted my Heinekan can pot. Last trip I used a new one, no paint yet, I think it took about 2 minutes longer to heat 2 C water than the painted one, but then I forgot to put up my wind screen for the first half so,,,,,,,
Doctari.
Footslogger
07-24-2006, 09:44
[quote=Doctari]But what I do know is: most engine paints get slick(er) when heated, (prolly to make your engine look shiny) causing your pot to gracefully slide off the stand.
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Oh man ...that alone makes me want to go with the paint, quicker boiling time or not.
Thanks for making that point !!!
'Slogger
[quote=Doctari]But what I do know is: most engine paints get slick(er) when heated, (prolly to make your engine look shiny) causing your pot to gracefully slide off the stand.
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Oh man ...that alone makes me want to go with the paint, quicker boiling time or not.
Thanks for making that point !!!
'Slogger
:D I can see it now: Slogger sets up his stove, "not quite level", black pot full of water, lights up. a few minutes later, jsut as the water begins to boil, SLICK! Off slides the pot, Slogger giggles, & starts over (& over, & over, & over) Till falling over laughing.
"So, Footslogger, why is your pack so HUGE? Well, I am going totally ultralight, but watching my pot slide off when heated is SO MUCH FUN! I'm carrying 5 gallons of fuel, hehe, hehe, hehe!" :p
Sorry slogger, couldn't resist :eek:
Doctari.
Footslogger
07-24-2006, 10:39
[quote=Doctari
Sorry slogger, couldn't resist :eek:
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Tsokay ...
Hasn't gotten that bad yet but I must admit that the little Ti pot does slip and slide more than I'd like. I have a little wind screen now though that attaches directly to the stand and keeps the pot in place.
All in all though ...it's staring to sound like the black paint is a good idea. Just happen to have a can of the high heat grill paint on hand and will probably give my pot a coating tonight.
'Slogger
...then I can cut down on all that water I am carrying !!
Rain Man
07-24-2006, 10:52
All in all though ...it's staring to sound like the black paint is a good idea. Just happen to have a can of the high heat grill paint on hand and will probably give my pot a coating tonight.
I paint all my pot bottoms black too and believe it speeds up boil time noticeably (though I suspect a good wind screen helps much more).
One word, which I think you may already know, but there are two types of paint out there. The one for engines is not rated for very high temps, perhaps up to 500 degrees, if I recall.
The "good" kind of paint is the kind for grills. It is rated for a couple thousand degrees (again, if I recall correctly). That's the kind I went for.
Any of it will scratch and wear off, but not as fast as regular soot does, nor will the paint wash off like soot does. For what that's worth.
Rain:sunMan
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Skidsteer
07-24-2006, 17:48
As others said, use the hi-temp grill paint. WRT faster boil times; My test result indicate a definite maybe. :D
johnny quest
07-24-2006, 18:00
i always painted my aluminum pots and canteen cups. havent painted the titanium yet. it take the paint as well?
Footslogger
07-24-2006, 18:02
i always painted my aluminum pots and canteen cups. havent painted the titanium yet. it take the paint as well?
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I'll find out tonight. Probably will only paint the bottom side and a little around the bottom edges.
'Slogger
Skidsteer
07-24-2006, 18:26
i always painted my aluminum pots and canteen cups. havent painted the titanium yet. it take the paint as well?
Yes. I painted one of my titanium pots. It seems to hold the paint as well as aluminum pots.
SGT Rock
07-25-2006, 06:17
I Any of it will scratch and wear off, but not as fast as regular soot does, nor will the paint wash off like soot does. For what that's worth..
Just don't wash your pots, it will last a lot longer :D
Im not sure what the grill paint is designed for, but if it is to paint grill housing than I doubt heat conductivity is high on their list of goals. In fact, if I were designing a paint for a grill, I would want it to act as a mighty good insulator so as to prevent heat from escaping through the lid and sides.
If this is the case, then I would expect the paint to act as an insulator between the pot and the stove, thereby increasing the boil time. Painting the bottom of the pot would then have the opposite effect that you are looking for. Though painting the sides though would add some amount of insulation there (like a very very thin pot cozy).
I think that in all likelyhood, the painted pot will boil at the same rate as a non painted one, maybe even a little bit slower.
If you happened to get hold of some paint that is designed for heat conductance, then you might see a quicker boil but even in this case I doubt it would be noticable. Maybe you could boil 50 gallons in 5 minutes less time, but that translate to less than a second when cooking the amount that you would be. There are way to many other factors that affect cooking time for this to be a major concern.
Unless somebody can show a real experiment (2 of the same pots side by side, one painted, same conditions, multiple trials), I think that any effect may just be perception.
Footslogger
07-25-2006, 14:40
Unless somebody can show a real experiment (2 of the same pots side by side, one painted, same conditions, multiple trials), I think that any effect may just be perception.
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I kinda feel the same way. But, there was this person a while back who did a study. Just can't seem to lay my hands on it now. Don't think we're talking an order of magnitute of difference here though.
That said ...if a little flat black paint does make the undersurface of the Ti pot a tad less slippery then I'm willing to give it a shot.
'Slogger
LostInSpace
07-25-2006, 16:36
There may be some misconceptions about thermal transfer and the "color" of the pot. People might think that because black absorbs more light it will absorb more heat. However, what happens in the visible light spectrum is not necessarily what happens in the infra-red spectrum. I don't know much about the physics of the heat transfer from a flame to a metal object. However, although it's counterintuitive, I know that aluminum painted white reflects more heat than shiny aluminum because the coefficient of reflectivity (inverse of conductivity) of the white paint is higher than that of the aluminum in the infra-red spectrum. This is one of the reasons that exposed electronics housings are often painted white. So, who knows if the black pot really does conduct better.
I have some doubts about the advantages of painting a pot black. As I understand it the primary mechanism for heating the pot is conductive heat from the burning gases to the pot and not from radiation from the light and infra red radiation from the stove. Since it is my opinion that the conductive heat transfer dominates adding paint to the pot is on a par with adding a thin coat of insulation to the pot - not a good idea for improving efficiency. A better choice would be to roughen the surface of the pot to increase the effective surface area or possibly to use a pot with a bigger bottom.
fiddlehead
07-26-2006, 10:01
After buying a titanium pot, i discovered that it seemed to take longer than my old aluminum one. But i didn't do a proper test. I did switch back to aluminum.
So, i'm asking here if anyone has done a test on titanium pots vs aluminum pots for quicker boiling times?
As for color, all my pots turn black because i sometimes use fires and carry my old Zip stove once in a while when i'm traveling overseas. But when i'm in Nepal, the Sherpas always clean the black off. i've seen them work at it for over an hour already to do it. They like them shiny.
Footslogger
07-26-2006, 10:08
[quote=fiddlehead]um.
So, i'm asking here if anyone has done a test on titanium pots vs aluminum pots for quicker boiling times?
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No, I haven't BUT ...I own both and 2 identical stoves so I wil do a side-by-side test (maybe tonight) and report back on the results.
'Slogger
fiddlehead
07-26-2006, 11:41
That'd be great Slogger, i've been wondering that ever since i spent all that money for something i never use.
Skidsteer
07-26-2006, 18:25
So, i'm asking here if anyone has done a test on titanium pots vs aluminum pots for quicker boiling times?
I've done informal tests(meaning I didn't record the results:D ).
In general, my aluminum pots boil faster than my titanium pots of the same size when using the same stove.
But there are other factors that are hard to control like shape of the pot bottom, thickness of the material, thinking happy thoughts, etc.
As I remember, the time difference was pretty small.
i know i've seen a hybrid aluminum and titanium pot, where the bottom was aluminum and the the rest of the pot was pure titanium... it seemed like a good idea because of the increased heating efficiency, good strength and low weight. now where was that link...
mike!
Lanthar Mandragoran
07-27-2006, 16:00
I have some doubts about the advantages of painting a pot black. As I understand it the primary mechanism for heating the pot is conductive heat from the burning gases to the pot and not from radiation from the light and infra red radiation from the stove. Since it is my opinion that the conductive heat transfer dominates adding paint to the pot is on a par with adding a thin coat of insulation to the pot - not a good idea for improving efficiency. A better choice would be to roughen the surface of the pot to increase the effective surface area or possibly to use a pot with a bigger bottom.
Yup, basically the more contact time you can get, the more effecient the heat transfer... this can be done by a wider pot... a concave pot bottom... or (to some extent) roughening the pot bottom... also a well-designed windscreen will both reduce convective heat transfer from the wind as well as increase residency time of hot gasses on the pot...
Radiant heat transfer is a tiny part of the equation, and paint has a good chance of insulating as much as helping (though the flat black may add friction to the bottom slowing the gases and increasing residency time... but again, this is going to be marginal at best)...
Footslogger
07-30-2006, 21:13
Well sports fans ...here are the results you have all been waiting for.
First off, I have no intention of trying to prove or defend my results. Read, enjoy, reject ...I'll still sleep well.
WYSIWYG !!
TEST >>
A) To see if there is any difference in boiling times between an Aluminum and Titaium cookpot
B) To see if painting the cookpots black has any effect on the performance (eg boiling time) of the 2 cookpots.
Materials: Evernew Titanium 1.3 Liter Cookpot and a somewhat generic 1.3 Liter Aluminium Cookpot (Walmart)
Stoves Used: 2 Trangia Westwinds with Denatured Alcohol.
Process A >>
Placed 8 oz of cold (tap) water in each cookpot
Placed 1 oz of denatured alcohol in each of the stoves.
Set stop watch to zero.
Lit both stoves and allowed the central flame to extinguish leaving only the ring of blue flame emitting from the top of each stove.
Placed the cookpots on top of the potstands and started the stop watch
Results TEST A >>
At approximately 3 minutes/30 seconds there were visable gas bubbles at the bottom of both pots. NO ...I didn not try to quantify the difference in the number of bubbles.
At approximately 4 minutes there were gas bubbles rising to the surface of the water in both cookpots. There appeared to be MORE bubbles rising in the ALUMINUM cookpot (for whatever that is worth)
At approximately 4 minutes/30 seconds there was a ROLLING BOIL noted in both cookpots.
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TEST B >>
I then allowed each of the cookpots and stoves to fully cool. I dried off any visable remaining water from the cookpots and placed them upside down on newspaper and painted them black using Krylon Barbque Grill High Heat spray paint (Walmart). I did not measure the paint used. I pained one cookpot at at time and simply applied the paint until the base metal was fully covered on both cookpots.
I repeated the process outlined above in PROCESS A
RESULTS >>
The results were virually identical as outlined above for PROCESS A
CONCLUSIONS
1) Under the circumstances/conditions outlined above there is no significant observable difference in the boiling time of 8 oz of water using either a Titanium or an Aluminum cookpot and an alcohol stove.
2) There is no significant observable difference in the boiling time of either a Titanium OR Aluminum cookpot if it is painted black.
POST SCRIPT
I did notice that in the case of both (Titanium and Aluminum) cookpots, painting the undersurface DID reduce the tendency of slippage on the standard Trangia Westwind pot stand.
Therefore, although there is virtually NOTHING to be gained in terms of performance between a Titanium and an Aluminum cookpot, regardless of whether it is in its natural state or painted black, I have decided to paint the bottom of my 0.9 Liter Evernew Titanium cookpot black prior to my next backpacking trip to reduce slippage.
About the only other comment I will make is that I have heard/read that (unconfirmed sources) Aluminum is suspected to be linked to some health disorders. Who knows ...next year we might learn that Titanium and it's alloys are equally or even moreso toxic.
Please take the above results/comments with a grain of salt. This was meant as an experiment for my own edification and I just decided to share the outcomes for what it was worth.
NOW ...WHAT'S FOR DINNER ??
'Slogger
Aluminum is suspected to be linked to some health disorders
I heard that too, but as hard as I try, I just can't remeber what thery are.
RockyTrail
07-30-2006, 21:29
I have some doubts about the advantages of painting a pot black....Since it is my opinion that the conductive heat transfer dominates adding paint to the pot is on a par with adding a thin coat of insulation to the pot - not a good idea for improving efficiency...
I worked with an electronics packaging engineer on a similar problem...the metal box we were working with was running just a shade too hot for the electronics inside. The solution they came up with was to simply paint the bare aluminum housing; it was good for a 10C temp reduction due to additional radiated heat. I asked him about the paint color...he said the color did not matter, it was the presence of organic material in the paint that mattered. For some reason the organic compounds (carbon?) emit heat better than bare metal. The company ended up actually using a clear paint that worked quite well. I think there are a lot of factors involved in heat transfer and without some experience and test data it's tough to predict it just based on "white" or "black" paint description. Just an FYI...
Rain Man
07-30-2006, 22:25
Well sports fans ...here are the results you have all been waiting for.
First off, I have no intention of trying to prove or defend my results. Read, enjoy, reject ...I'll still sleep well.
...
CONCLUSIONS
1) Under the circumstances/conditions outlined above there is no significant observable difference in the boiling time of 8 oz of water using either a Titanium or an Aluminum cookpot and an alcohol stove.
2) There is no significant observable difference in the boiling time of either a Titanium OR Aluminum cookpot if it is painted black.
Slogger, I thank you for your experiment and report!
Rain:sunMan
.
Thank you for your test & report. I'm still going to paint my Heinekan pot black, "just because" but now I know I'm doing it just to amuse myself :p
Well, that & I put 1/16" x 1" pieces of tape at each 1/2 cup mark on the can prior to painting, then after aplying the paint, BEFORE it dries, peal off the tape. Presto, a gradiated measuring cup.
Thanks again. Great report!
Doctari.
Footslogger
07-31-2006, 14:20
I heard that too, but as hard as I try, I just can't remeber what thery are.
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Found a reference related to the health risks from aluminum:
http://www.agr.gc.ca/pfra/water/alhealth_e.htm
"Unlike iron, aluminum is not known to have any direct, positive health effects on humans. Adverse effects of aluminum are currently known to be far more chronic (occurring over the long term) than acute (occurring in the short term). Aluminum has been shown to be a neurotoxic compound if it is allowed to enter the bloodstream. Long-term exposure of patients to dialysis water high in aluminum may cause encephalopathy (defect of the brain) and/or bone mineralization disorders.
Aluminum has also been suggested as a cause of Alzheimers disease, Lou Gehrig’s disease and other forms of senile dementia. It is still unclear if aluminum leads to these diseases or if it is that the diseases cause brain tissues to retain aluminum secondarily.
It has not been shown clearly that normal eating or drinking in a healthy individual will cause elevated aluminum levels in the blood. This is true even if all cooking is done with aluminum pots and utensils."
fiddlehead
07-31-2006, 21:26
Thanks for doing the test. I've been wondering about this for years. I bought a titanium pot but don't use it. (I like the handle on my aluminum one better, and i always thought that the aluminum one heated water quicker, now i know)
It still doesn't seem to make sense that one cost 20 times more than the other.
One more observation: i live and work in thailand and play in a band with 3 people from England. We often talk about the problems with American English. Two of the words that i use a lot that really bothers them the most are: aluminum (which they say: al-u-min'-ee-um) and solder (the stuff you melt electrical wires together with) (they say it like it's spelled, with the l) Anyway, there are many more words of course but it bothers them sometimes how we butcher the english language. (It's not the Queen's English)
But thanks again for that test. It's scientific enough for me.
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Found a reference related to the health risks from aluminum:
http://www.agr.gc.ca/pfra/water/alhealth_e.htm
"Unlike iron, aluminum is not known to have any direct, positive health effects on humans. Adverse effects of aluminum are currently known to be far more chronic (occurring over the long term) than acute (occurring in the short term). Aluminum has been shown to be a neurotoxic compound if it is allowed to enter the bloodstream. Long-term exposure of patients to dialysis water high in aluminum may cause encephalopathy (defect of the brain) and/or bone mineralization disorders.
Aluminum has also been suggested as a cause of Alzheimers disease, Lou Gehrig’s disease and other forms of senile dementia. It is still unclear if aluminum leads to these diseases or if it is that the diseases cause brain tissues to retain aluminum secondarily.
It has not been shown clearly that normal eating or drinking in a healthy individual will cause elevated aluminum levels in the blood. This is true even if all cooking is done with aluminum pots and utensils."
Well, I no longer cook with Aluminum at home any more -- except when I have a crowd coming for lobsters and my only pot big enough to hold all the lobsters is aluminum.
It's my theory that Aluminum's health effects, if any, are related to how often one uses such pots. But I've seen no evidence that using a large aluminum pot occasionally to cook lobsters, or, a smaller pot, occasionally on an occasional backpacking trip is harmful.
Weary
Dances with Mice
07-31-2006, 23:02
It has not been shown clearly that normal eating or drinking in a healthy individual will cause elevated aluminum levels in the blood. This is true even if all cooking is done with aluminum pots and utensils."Other medical researchers (http://i67.photobucket.com/albums/h299/raystern/rhps/rhps.jpg) agree. (http://www.snopes.com/movies/actors/valentin.htm#add)
Skidsteer
07-31-2006, 23:40
Other medical researchers (http://i67.photobucket.com/albums/h299/raystern/rhps/rhps.jpg) agree. (http://www.snopes.com/movies/actors/valentin.htm#add)
So let's all wear aluminum hats and do the time warp again. :D
Alligator
08-01-2006, 13:10
So let's all wear aluminum hats and do the time warp again. :DIt's just a jump to the left,
and then a step to the right...