Technical Antifreeze / Thermostat Experiment - possible or not?

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Technical Antifreeze / Thermostat Experiment - possible or not?

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Hey guys

This is another one of my more ' just a curiosity' posts. A Bit like the one I posted asked what would happen if u had 4 individual brand of spark plug in.

When needing to test a thermostat, you often read to suspend it in boiling water in a pan. But this only works for for stats that open at around 90 - 98c. For stats that open up at hotter temps 103c - 105c. Could you in theory, have a pan with a 50/50 mix and boil that to allow for a higher boiling point.

I've tried researching this but it's seems to be one of those posts where Google just does not know [emoji3]
 
Sounds reasonable. According to this website a 50/50 mixture of water and ethylene glycol boils at 106°C (standard atmospheric pressure). 30/70 takes it up to 113°C

Waterless coolant would be another option (Evans boils at around 190°C).

Clean the pan thoroughly afterwards!
 
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Here's an article on thermostats by a professional engineer:

http://www.davidboettcher.uk/thermostat.php

Down near the end:

When testing higher temperature thermostats it should be noted that an 88 degree thermostat will not be fully open until 100-103 degrees, likewise a 92 degree thermostat will not be fully open until 104-107 degrees. The valve will not open fully when immersed in plain boiling water alone because the boiling point of water is 100 degrees centigrade at sea level. To test higher temperature thermostats they need to be heated in a water/ anti-freeze mixture or cooking oil, which will allow the temperature of the coolant to be raised above 100 degrees.
 
Dangerous way to test such thermostat would be pressure chamber (boiler) and using water-steam mix, then you can go above 100°C with water. Not recommended of course (kids, don't try this at home).

PS
"Professional engineer"... :shakehead: They can't explain the very basics.
Car "cooling system" is there to stabilise the temperature, mostly (most of the time) by cooling (but it's not only to cool - that's simplified version).

Most important points (mr. engineer "forgot" to tell you).
1. "High" (80-100°C) temperatures are NOT "optimal" whatsoever! In terms of mechanical engineering, fits/clearances, and so on.
2. It's a big trade-off between radiator size and its ability to dissipate energy (heat).
To do this you must operate way above the ambient temperatures. That's the trick (it's not clever, rather primitive, savage).
3. If radiators were much bigger, you could design the engine with for example 60°C or maybe even 50°C as The "Optimal" temperature. Easily.

The same primitive method is used in the electronics world. For example, precise frequency generators are stabilized (ovenised), using thermostat. Guess the temperature: it's about 80°C mostly too. To be always above ambient (that's main reason why such high value is "optimal", otherwise there's nothing special about it).
 
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Most important points (mr. engineer "forgot" to tell you).
1. "High" (80-100°C) temperatures are NOT "optimal" whatsoever! In terms of mechanical engineering, fits/clearances, and so on.
2. It's a big trade-off between radiator size and its ability to dissipate energy (heat).
To do this you must operate way above the ambient temperatures. That's the trick (it's not clever, rather primitive, savage).
3. If radiators were much bigger, you could design the engine with for example 60°C or maybe even 50°C as The "Optimal" temperature.

I believe this "optimal" temperature comes from the steam engines, which by essence (sorry for the pun) were working at high temperature and therefore the engineers HAD to design them accordingly. Also a part of the steam was condensed back to water to feed the boiler, as hot as possible but still in liquid state, which strangely is just below 100C (@ 1 atm) .
It is also pretty obvious that when fuel burns it produces heat, which is converted in force applied on the piston(s), one can't avoid that ! So the less heat dissipated, the more can be converted to force. Here again we are at "optimal" temperature where the engine is as hot as possible and the coolant is still liquid. As the engineer says, vapor is poor in terms of thermal exchange so the coolant MUST stay liquid and pressure must be kept reasonnably low for safety and build simplicity...
And BTW the Guy says clearly in the text that the thermostat regulates the coolant FLOW and therefore maintains the engine temperature mostly constant.

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
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Don't boil it on a cooker, as AntiFreeze is flammable.
Maybe sugar might be a safer way to increase the boiling point.
 
Yes Bernie, many solutions in mechanical world, comes directly from the steam engines, locomotives era.
Mechanisms, gears, levers, linkages, slides, valves, shafts, plain bearings, lubrication and cooling mostly with water back then.
Therefore "optimal" values. Still in use today, because trade-offs (radiator size, ambient temperatures, coolant type, an so on) and historical reasons (engineer should know this and mention it). Combustion process, thermodynamic reasons, not so much (especially with modern cars, with a lot of sensors and engine management, ECU controlling the process).

Some coolant history: http://www.crankshift.com/history-of-antifreeze/ https://en.wikipedia.org/wiki/Antifreeze#Principles_and_history

PS
Thermostat can be also carefully heated with a heat (hot air) gun... So, no liquids or fire involved.
 
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Solutions like boiling antifreeze or using a pressure cooker seem like a health risk and possibly messy to me.
Why not put the thermostat in an oven and use one of those meat thermometers to track the temperature?
 
I would go for oil in a pot AND the meat thermometer.
Heat slowly and watch what happen when temp reaches about and above 85C ...

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Hey guys, thanks for response, really learn some things. Any correct me if I am wrong, i think i will try maybe the heat gun method. The thermostat I am playing around with is the type where it is built in a plastic house system so removing the metal coil isn't possible and has a connection for a wiring harness. Seems the safest i.e no fires and also not damaging the actual thermostat? I doubt it would be re -used but im very Mr dont like to break things for the sake of it
 
Hey guys, thanks for response, really learn some things. Any correct me if I am wrong, i think i will try maybe the heat gun method. The thermostat I am playing around with is the type where it is built in a plastic house system so removing the metal coil isn't possible and has a connection for a wiring harness. Seems the safest i.e no fires and also not damaging the actual thermostat? I doubt it would be re -used but im very Mr dont like to break things for the sake of it

Lol, out of all the great solutions people in this thread came up with the heat gun seems the worst choice. It gives you no control over the actual temperature and it's easy to overshoot it and melt the plastic housing:D
 
Sure enough the air gun is the worst, IMO the oil in a pot/meat th° combination is the best since it'll give you control over temperature, visibility and similar conditions (direct contact/immersion) compared to the real usage.
The connection someone refered to is the coolant temperature sensor ...

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Cooking plastic+rubber parts in the oil is a bad idea. You'll never know what's going to happen (some reaction).
Heat gun is OK, acceptable method, if you check The Thermostat, NOT entire thing, thermostat in the housing!
I thought most of you are clever enough to spot the difference...
Because most thermostats are removable from the housings. Just push it (spring loaded retainer).
Thermostat_VS_thermostat_HOUSING.jpg
 
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Can't agree with you GP-PL ! With the air-gun You still couln't tell what's the opening temperature !! Of course with the oil method You should NOT heat it higher than 100ish°, which won't hurt the components since that'd be the functionning temp anyway ...

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
Almost any heat source will do for DIY quick rough check (but mind the plastic/rubber components).
And if you want to be more scientific, build a test jig, pressure chamber (where you can control the pressure and temperature) or something like that.

Thermostat opens when hot or not, most of the time (it's almost "digital" component: zero/one logic, works or not).
Exact temperature is not that important (if you think it is - make a real test, under pressure and so on).
If it's not working in the housing, it's stuck there mechanically - disassembly, cleaning, assembly can often fix it.

Or don't bother - buy a new one.

OK, I'm out. This will be (probably) another topic, with multiple pages of (almost) pointless yapping.
 
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If you’re testing a thermostat, you’re wanting to know precisely what temperature it is or maybe isn’t opening at.

The archaic method of putting it in water, heating it slowly watching the temperature on a thermometer and then watching the stat closely has not changed for decades because it doesn’t need to change. It’s simple and it does what it needs to do accurately.

Blasting things with a heat gun has no accuracy whatsoever, ok you can see if the stat opens and closes with heat but you have no idea at what temperature or if it’s sticking at a certain point. You not only risk damaging the plastics of the stat but also of burning/boiling the wax in the stat, causing it to leak or not work properly in future. Using a heat gun is of no sensible use whatsoever in testing a thermostat properly.

I would probably not put a thermostat in oil. If at worst you need to heat it to 103 - 105 degrees this could be achieved with a relatively weak mix of water and coolant, Yes glycol coolants are flammable but then so are cooking oils. Mixed with water increases the flash point and with low concentrations it shouldn’t be an issue, taking care and doing things slowly.

The main point I would make are that thermostats are often so cheap and so reliable that virtually no one tests them anymore. Why spend all that time testing it, when a replacement can be as cheap as £10 sometimes less. Even a more expensive thermostat would be better replaced if you have doubts, as the trade off is the price of a £50 thermostat verses a Hundreds orThousands For the price of a head gasket or even the whole engine.

If it’s just out of interest as you have one laying about doing a test with plain water is sufficient.

Never try and build any sort of pressure vessel for boiling water yourself, there a laws in the U.K. that govern such things, and for a very good reason, because these things can very easily kill, and it’s just not needed for a £10 thermostat test.
 
A heat gun is a bad idea, it will not provide even heat. It will overheat plastic components. A water gycol (antifreeze) mix is not flammable and is probably the best / safest option. Just remember to dispose of it properly (keep it for topping up?) as it's toxic.

Robert G8RPI.
 
Heat source type does NOT matter if someone is an idiot with "two left thumbs": he/she will destroy the thermostat (with or without housing), burn himself, burn or blow up the house, and contaminate the environment. So what?

Is this a technical forum or we judge "average Joe" skills (and if he'll do any damage)?
Erase all forum Guides then (all potentially "dangerous" if performed wrong).

Technically speaking, heat source does not matter much - it's the way you use it, apply it and control it.
"Primitive" sources like fire, hot air, IR (infrared) are still in use, in the serious industrial applications.
And the temperature is controlled well (any PID controller will do +/- 1 degree).
I know, it's too complicated for most of you to grasp (what's technically possible and what's not), so it's easier to ridicule the idea/concept.

Still got a problem? Give me a 10 dislikes, minimum! That's all you can do about it (politically correct sissies).
 
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