Scuttle Wars: Round 2 (Request to all the scuttle owners out there!)

[PolsBirthday]

I've started a couple threads on scuttles, but I think everyone would be much better off if I proposed something of a quantifiable, scientific request in lieu.
Thus, to prove once and for all which scuttles hold their temperature the best, please attempt the following if you are a scuttle owner(and post the results below!):

1. Get hot water

2. Measure the temperature of this water.

3. Pour said water into your scuttle.

4. Measure the temperature at a series of evenly spaced intervals of your choice
(Every 2 minutes is probably more than generous enough, but feel free to be more or less robust at your choosing)

5. Post your results here! I will be collaborating all the results together to produce an accurate comparison of the degradation of heat in different types of scuttles.

*For an added bonus, you may want to try to build a lather in your scuttle, and take a temperature reading of the lather itself; however, this will be more auxiliary, as the accuracy will not likely be as sharp.

Credit to JPM for originally measuring his scuttle temperatures and posting them.
This takes more than a few mouse-clicks, I know. But for Science!
(feel free to include photos of your scuttle, and don't be afraid to submit home-made contraption results!)

Edit: Boiling water is I guess not the best idea.

[PolsBirthday]

Nobody eh? Perhaps this is too much work for internet strangers...

[Donmuerto]

I think the quest for quantitative data is great, but pouring boiling water into a scuttle is not safe or recommended.

[djm2]

Background: I don't use a scuttle so I'm not one of the chosen for this deal. But let's evaluate this: You post in the early morning and expect that within 11 hours people have necessarily seen your posting and flocked to do the testing work that you have requested. I'm sorry, but IMHO that sounds just a tad self-absorbed, and I would blow this off for that reason alone.

[ackvil]

I think the quest for quantitative data is great, but pouring boiling water into a scuttle is not safe or recommended.

The instructions that came with my scuttle said NO to boiling water.

[PolsBirthday]

Background: I don't use a scuttle so I'm not one of the chosen for this deal. But let's evaluate this: You post in the early morning and expect that within 11 hours people have necessarily seen your posting and flocked to do the testing work that you have requested. I'm sorry, but IMHO that sounds just a tad self-absorbed, and I would blow this off for that reason alone.

I am not of course doing this for solely my own benefit, I should think anyone considering a scuttle would want these most important facts, but if I have been too arrant, so be it. My comment was more of a bump than a depredation anyway.

[rajagra]

Good idea. I have already done this but never got round to posting the details.

Can I point something out? Most of the data I have seen of this nature has been rendered hard to compare because people don't say what the ambient temperature is!!!
This can be overcome if enough data points are given so you can calculate the exponential decay rate, but usually they are not.


Here is the data I got from testing my Steve Woodhead extra large scuttle:
Pictures here.

             Temp. °C   Temp. °F
Ambient:      10         50
        
Time (mins)  Temp. °C    Temp. °F
0             67        152.6
5             64        147.2
10            61        141.8
15            58        136.4
20            54        129.2
25            50        122
30            48        118.4
35            46        114.8
40            44        111.2
45            42        107.6
50            40        104
55            38        100.4
60            37        98.6
65            34        93.2
70            33        91.4

This shows a temperature half-life of 55 minutes, i.e. T=ambient temp. + initial temp. difference /2^(t/55)

The main chamber holds 1 3/8 UK pints = 27.5 UK fl oz = 26.4 US fl oz = 0.78 L and this amount was used for the test.

[Angry__Panda]

Wow you would blow it off because he is excited about this? I am more interested cause he is sticking with it even with not a whole lot of results yet.

I see a lot of people saying that their scuttles said no to boiled water...And then probably add in the ambient temperature.

So, why don't you have people start with a table kind of like rajagra did...Give the ambient temperature, then give your start temperature, then the temp every 5-10 minutes (probably better to keep it at shorter intervals).

If I had a scuttle (which I am debating buying actually heh) I would be glad to help, unfortunately I don't have one yet. I could offer up the test using a homebrew type scuttle though (i.e. a bowl inside another bowl) if you'd like?

[Donmuerto]

In addition to ambient temperature, I would add that volume of water is important too. Rajagra included the volume, but did not call it out as an variable to record. I say it is critical, and it is also easily recorded: Fill up your scuttle, and empty it into a measuring cup when done.

[Barefoot Joe]

Not to make this more complicated than it has to be, but what you are measuring is the temperature drop of the water in the outside bowl of a scuttle. What really matters is the surface temperature of the innermost surface of the inner bowl. That could be influenced by the outer bowl thickness, inner bowl thickness, heat retention/radiation properties of either, water volume, whether you preheat the scuttle before adding water, etc., etc. So, in summary, I would choose a scuttle based primarily on it's color.

Or, be like me and get a "Dirty Bird with a Dribble Hole", because I like the way that sounds.

[brucered]

here are my numbers.

Dirty Bird 1.5 with a depth the same as the DB1.0. test was conducted with tap water (not boiling or modified), emptied to measure roughly 23oz or 650ml. bowl was empty, so may be affected if it had shaving cream in it.

00min 133.0°F
03min 126.2°F
06min 124.5°F
09min 122.7°F
12min 120.7°F
15min 118.4°F
18min 116.5°F
21min 114.5°F
24min 112.7°F

went for supper, came back at
41min 104.8°F

hope that helps. so a typical 15min shave the temp would drop about 15°F for me.

[fine wine]

You guys are starting to freak me out. Is this test to see which holds the temp the longest or what? I use just less than boiling water, I bring it to a boil then let it set for a minute then put it in my scuttle, it's a becker brand. But before I go to the troble to do this it would be nice to know what are we looking for?..........................JR

[brucered]

You guys are starting to freak me out. Is this test to see which holds the temp the longest or what? I use just less than boiling water, I bring it to a boil then let it set for a minute then put it in my scuttle, it's a becker brand. But before I go to the troble to do this it would be nice to know what are we looking for?..........................JR

I think it's just to see which scuttles hold the heat the longest. since we are all using different temp initial starting water, there is no way for it to be 100% accurate.....but if we have a few different scuttles tested to see what the temps drop in the water, we can have a general idea as to which hold the temps the best.

if nothing else, it's something to do when you are bored.

[PolsBirthday]

Not sure how to compensate for ambient temperatures and lack of lathers and such, but here is a preliminary between the two we have now. (If you have recommendations let me know)

I suspect these are actually the same, however, due to rajagra likely living in the arctic somewhere, there is a steeper decline and a higher R^2 value.

[Barefoot Joe]

Despite some limitations in measuring the temperature drop of water in the outer bowl over time, I am sure there is a correlation of that with the inner surface of the inner bowl. May I humbly suggest what may be a useful calculation?....

Since an average 3 pass shave is about 20-30 minutes (I'm guessing), using that time frame seems practical, e.g. most people won't care what the water temp will be in 1 hour. Starting with different water temperatures makes the data a little difficult to interpret intuitively (although I love your graph!). Using a simple number, either a % drop in temperature over time, or possibly the slope of your graph, might make scuttles easier to compare relatively.
Of course, you need the raw data to make it meaningful (the mo, the betta).

Interesting project. Kudos!

[rajagra]

I've been playing with spreadsheets and graphs. I think the test could be reduced to:

• Fill scuttle with hot water;
• Wait 5-10 minutes for the temperature to stabilise between water and scuttle;
• Preferably record ambient temperature;
• Measure the temperature 3 times at even intervals (e.g. at + 0 mins, 15 mins, 30 mins).
• Note what you are standing the scuttle on (directly on a counter, towel or cloth, etc.)

This is enough to work out how often the scuttle loses half its heat, and from that you can plot a graph of how it will work given any room temperature and any starting temperature.

I've worked out how to guesstimate the ambient temperature from any 3 evenly spaced measurements, but the process will be more accurate if room temperature is measured.

Spoiler:

For 3 evenly spaced temperature measurements T0, T1 and T2, the ambient temperature is calculated by:
(T1² - T0×T2) ÷ (2×T1 - T0 - T2)

Examples follow...

Case 1. My Steve Woodhead 780ml scuttle. Temperature drops half way to ambient every 53.14 minutes. Recorded values closely match theoretical values (I measured in °C which is a coarser measure than °F, explaining small errors.) I allowed everything to settle for a few minutes before starting measurements. I had the scuttle stood on a rubber mouse-mat-type-thingy which is how I actually use the scuttle, and will affect performance.



Case 2. Brucered's Dirty Bird 650ml scuttle. Temperature drops half way to ambient every 30.38 minutes. Recorded values closely match theoretical values except at the start where the temperature dips rapidly as the system settled. Brucered presumably started measuring right away after adding water. I'm going to assume he had the scuttle stood directly on a counter surface, making the cooling rate faster.

However - I had to estimate his ambient temperature. At 88°F. I did this by ignoring the first 3 unstable readings and working out where the remaining values were heading.



How about a theoretical comparison, based on the above estimates? Will be happy to correct this if the calculated room temperature was way off...

[brucered]

my DB1.5 test started measuring the temp right away as you speculated, but the scuttle was placed on a dish cloth on the counter, if that makes a difference.

[Alraz]

This is an amazing experiment, congratulations to all the entrants.... I have a little question about comparing the data: how are you guys going to account for differences in "ambient" temperature? or, should they be considered negligible?

Al raz.

[Donmuerto]

It seems to me that volumetric differences prevent meaningful comparison. All other things considered equal, I would absolutely expect a 780ml volume of water to retain heat significantly longer than a 650ml volume. A "half-life" of temperature seems conceptually flawed as thermal dissipation is not analogous to radioactive decay at all.

In the experiment at hand water in contact with the outer and inner sides of the scuttle is where the heat loss occurs; only after that has 'cooled' do the ones closer to the center lose energy, then the next closer. etc. In a chunk of radioactive material, decay happens evenly throughout the volume of material.

I'm not a data analyst; is there some way to normalize volumetric differences to get an actual apples-to-apples performance graph with scuttles of different water volumes?

[brucered]

...snip...
I'm not a data analyst; is there some way to normalize volumetric differences to get an actual apples-to-apples performance graph with scuttles of different water volumes?

how about this...everyone send me your scuttles, all perform all test and analyse them etc, over the course of a few years and compile all the data. you won't get your scuttle back, but you'll know which one to buy next time.