Forums > Technical Discussion > Evaporating chemicals

Posted: 21st Apr 2003
Do you want to know what their comparative flashpoints are?

Or how toxic it is to breathe in the fumes?

Or soemthing else? Regardless, the best thing to do is to get hold of the MSDS sheets for all of them from your supplier.

For a rundown on MSDS sheets, have a look here Home of Poi MSDS page

By the way, I wouldn't listen to anyones advice on a bulletin board about properties of fuels and the associated hazards.

Nothing less than your own research and judgement (via MSDS if you want) should ever be used for yours and others health...

If you have trouble interpreting the MSDS's, take them into a drugstore/vhemist/pharmacy and ask the person with the degree to explain it to you.

HoP Posting Guidelines
* Is it the Truth?
* Is it Fair to all concerned?
* Will it build Goodwill and Better Friendships?
* Will it be Beneficial to all concerned?

Posted: 21st Apr 2003
Apparently I've got Australia's leading expert on chemical flamability living just near me, I was told to give him a ring about the properties of chemicals and oils I was considering about fire-breathing. I'll have a talk to him.

It's my world - you all just happen to live in it.

Posted: 22nd Apr 2003
Ayellayen...Why is this person considered an expert? On whose say so?

Is it form an industrial background?

From a performance background?

From a laboratorial background?


THIS IS VERY IMPORTANT FOR EVERYONE TO UNDERSTAND, take no-ones word for what they say about chemicals unless they back it up with facts figures and historical evidence.

There are so many tales and beliefs that can kill us, we should look at the facts as supplied via MSDS sheets and intepret them ourselves.

An example is that Kerosene is a name used for different chemicals in different parts of the world.

Even if someone knows what they are talking about and has a thesis on the subject, that doesn't mean that the fuel you are using has the same properties or the same mixture of contents as the fuel that was studied.

Assumptions to do with toxic chemicals are not only dangerous, you could end up hurting other people if they adopt your assumptions and spread them to other firies..

Sorry about the yelling, but this is subject very close to my heart.

We all need to be as informed as possible with the health risks we take, via skin absorption, risk of injury and what the smoke we inhale does to our body...

HoP Posting Guidelines
* Is it the Truth?
* Is it Fair to all concerned?
* Will it build Goodwill and Better Friendships?
* Will it be Beneficial to all concerned?

Posted: 22nd Apr 2003
Uh, I'll get back to you on that one.

*edit*

And note the first word of my earlier post "Apparently"

It's my world - you all just happen to live in it.

Posted: 22nd Apr 2003
The question you're asking from a scientific point of view is "vapor pressure"... something with a higher vapor pressure would more likely evaporate.

(Oops... gotta run!}

Well, shall we go?
Yes, let's go.
[They do not move.]

Posted: 22nd Apr 2003
I was just trying to find out how fast they evaporate. Not an exact number but a general idea or how to get these numbers.
It's for an experiment i am doing. Just trying to compare them to each other only in evaporation rates.

Thanks for trying to help but i dont think there is anything to helpfull yet.

the risk is the rush

Posted: 22nd Apr 2003
Evaporation depends on temperature, exposed surface area, wind, humidity.... um... I think there are more but I forget them now. So it will be different on a Florida summer day as opposed to a New York winter day.

If you let us know what your experiment is perhaps we could be more helpful.

Of course you could just get a scale and chart how much a soaked poi weighed vs. time. Then you'd know.

Well, shall we go?
Yes, let's go.
[They do not move.]

Posted: 22nd Apr 2003
I think your best bet would be to place the chemical on an electronic scale in an open container, like a petri dish so you have more surface area exposed so you can make your measurements quicker. Then record the weight in regular time intervals. try to make as many varibles constant as possible. All the ones nyc mentioned and whatever otheres there may be.

Then make a neat little graph for it and your done.

Posted: 25th Apr 2003
And also don't forget to measure volume as well, and to account for any differences in your invironment that may differ from Standart Temperature and atmospheric Pressure (STP).

Jesus helps me trick people.

Posted: 26th Apr 2003
What diffrence does the volume make? All he need's to know is the amount of weight change. A scale will more accuratly measure weight then a person can using the measureing lines on a container. If you find out the weight per ml of whatever substances you are using you can easily convert weight into volume.

Posted: 26th Apr 2003
Volume makes a huge difference.

The less of an evaporating substance there is, the faster it evaporates by %

This is of course assuming a number of things as constant and that there is a lot of exposure ot the atmosphere...anyhting more than this and I'll have to bow out ot NYC again.

HoP Posting Guidelines
* Is it the Truth?
* Is it Fair to all concerned?
* Will it build Goodwill and Better Friendships?
* Will it be Beneficial to all concerned?

Posted: 27th Apr 2003
hey again,
I am trying to get some numbers before i do the experiment.
Or like if Methylated spirits evaporates faster then Kersosene and Mineral Turpentine evaporates the fastes(i can't spell).
I know about the contributing factors but if they were all out at the same time which one will evaporate the quiker.(is that right )

L8er

the risk is the rush

Posted: 28th Apr 2003
Actually, you've got a bit of a scientific problem. The three things you stated are not pure chemicals but a mixtures of many, if not hundreds of, different chemicals each with different vapor pressure and evaporation rates.

If you were asking for a pure chemical, like methanol vs. a pure chemical like octanol, then the answer is pretty easy (the methanol is faster) but when you're asking for "evaporation rates" of coctails it becomes inexact.

That's why I think you should just try it.

Oh, here's a REALLY easy way to do it. Take a DROP of each and put it on a table or something. Then just watch which evaporates.

It's not exact (drops are different sizes) but it will probably be pretty good.

You can even smear the drop and it makes it even more apparent.

Good Luck and let us know

Well, shall we go?
Yes, let's go.
[They do not move.]

Posted: 28th Apr 2003
And... I'd help out but I don't use or have any of those three chemicals.

Well, shall we go?
Yes, let's go.
[They do not move.]