Mathanol / water mixture

[zakelwe]

Can anyone tell me roughly what the ratio of methanol to water is to stop it slushing / freezing at -30C ?

Also, what ratio stops the mehtanol mixture being flammable ( I think it is about 20% ).

Regards

Andy

[kommando]

Im not sure if this will help you but it might in some way.

[Gary Lloyd]

The pressure drops at the inlet of the pump, so you will need a stronger mixture than indicated in order to avoid freezing the pump.

[zakelwe]

Thanks Guys that is most useful.

I did it ad hoc in a plastic bottle in my freezer for the last two days, the first day was water 50:50 methanol and it did not freeze at all, yesterday I went 75:25 and it got slushy, this fits in nicely with Kommando's graph.

Taking Gary's point into consideration I think i will go for a 65:35 micture which should be about -35C. The less meths the better as i assume water carrys away heat better, it's not as flammable ( will test ) and it's cheaper.

Now I just have to find a cheap supply, my local store in the UK sells it for £2 per 500ml or $4 per pint :eek:

Thanks for the help

Regards

Andy

PS Gary I patched my freezer so it is waterproof and so rather than the inefficient plastic bucket in there the lqiuid will be up against the sides of the freezer. Hoepfully this will let me get the 3 hours benching 6-8 hours pull down I am aiming for ( it is not a 24/7 rig).

[zakelwe]

I did a flame test last night in a 50 : 50 water / methanol mixture.

Put a small bowl outside and fileld it with the liquid

Threw match in, match fizzles out. No flames to be seen of course, which was spooky. Put hand at a high level over the bowl to feel the heat and the invisible flames were obviously doing well.

tipped out out and watched the grass start to smolder as if by magic.

Very strange, and I'm not very happy about using it as a lquid to be honest, the problem with glycol is that it is just too gloopy.

Any suggestions ?

Regards

Andy

[iceman2g]

Are you using gas line antifreeze or buying just straight methanl? Wouldn't the this stuff be good enough.

[zakelwe]

Well I am going local stores and so I think it can be classed as "cleaning methanol " which is like racing methanol but with more impurities.

I filled up my freezer last night with 10 litres od water and 25 litres of glycol based antifreeze. At -20C it got slushy but did not leak, now added 5 litres of methanol, the slush went away and now hope I can get down to -30C with the mixture not being too thick for the Hydor pump, nor too flamable to be in the wooden shed I am building to house everything.

Whereas Chilly and Gary are using small quanities and professional skill I am using Bucket Chemistry .

If my silicone sealant goes brittle and contracts at -30C and the freezer springs a leak I am going to have 40 litres ( 8 imp gallons ) of glycol / methanol over the kitchen floor.

My wife will be sending me off to silicon heaven ... :)

Regards

Andy

[blinky]

i had a question about methanol

i went to kragen today, and they only had anti-freeze with glycol, so i talked to the guy and he told me to go to a european car dealer, and they might have some with methanol.

does anyone know where to get methanol if they dont have it at the dealer?

[gouda96]

Have you tried any auto parts stores? Or homedepot?

If I am planning on making a chiller that will do around -25c how much of a difference in temps would I see if I used a 60:40 methanol:water ratio compared to a 100% methanol mix. I will add some dexcool to reduce corrosion.

I have no issue with having a mix...I was just wondering...

[Gary Lloyd]

Gas line anti-freeze is methanol.

[iceman2g]

Also, what ratio stops the mehtanol mixture being flammable ( I think it is about 20% ).

Also wondering the same as i'm going out to buy some gas line antifreeze pretty soon.

[saratoga]

Originally posted by Gary Lloyd
The pressure drops at the inlet of the pump, so you will need a stronger mixture than indicated in order to avoid freezing the pump.

This isn't right. Fluids are not meaningfully affected by the pressures we have.

Also, lower pressure makes it harder to freeze, not easier. Otherwise you could lower the pressure of a gas and condense it back to a liquid.

[Gary Lloyd]

We are talking about a mixture. The danger is in evaporating the methanol and freezing the water.

[kayl]

on the anti freeze i use, it says a 50% will freeze at -37deg.
i can remember exactly but i think it was a glycol and something else, will update later with exact description
and it protects against a hole lot of metals,
brass, copper, aluminium and solder.

[blinky]

Originally posted by Gary Lloyd
Gas line anti-freeze is methanol. now how does methanol fare compared to isopropyl alcohol

like the pros and cons of each fluid

[Gary Lloyd]

DaBit has done considerable research on the subject. You may want to check out his website:

http://www.icecoldcomputing.com

[zakelwe]

This thread is so popular I wish I could change mathanol to a more ordinary spelling in the title ;) . Maybe I can pretende it is olde worlde English ?? ;)

I have got rid of methanol on safety grounds so am using thick glycol, therefore I am purchasing a Hydor L40 pump to go in series with my L30 pump and actually get the flow rate to more than a trickle.

Regards

Andy

[blinky]

Originally posted by Gary Lloyd
DaBit has done considerable research on the subject. You may want to check out his website:

http://www.icecoldcomputing.com yah i read his whole article, but then discussed it with people (peen) and he said to use isopropyl alcohol

is there something really dangerous about methanol? i dont mean its flammable, i mean if u inhale a little but can u not have enough O2 in ur lungs?

/edit dabit discounted isopropyl alcohol because its too viscous

[saratoga]

Originally posted by Gary Lloyd
We are talking about a mixture. The danger is in evaporating the methanol and freezing the water.

Ah I see. I don't think this is a real concern though. The vapor pressure of the methanol/water azeotroph is constant at a given temperature, so provided the container is sealed there should not be any seperation of the solution (otherwise the vapor pressure of one substance would rise which should not be happening).

At least I think so. Haven't experimented, but it seems extremely unlike that a water alcohol solution would come apart without a LOT of effort. Hence the trouble distilling liquior properly :)