Help me please...why is my tubing slowly compressing by themselves??

[BillA]

you blowing or sucking ?
lol

[ProHandyman]

Originally Posted by Joe

all the air will leak out over a while!

HOT air at that!

[nexxo]

Originally Posted by BillA

the 'problem' is that low permeability tubing is not available in the US
no extruder will touch polybutylene due to past legal problems in the housing mkt

nexxo/bobo
can you buy such in the UK ?
black and flexible (see the Japanese modular units)

I use Tygon. Over the last year I have not lost a single drop of Fluorinert which evaporates like crazy given half the chance...

[bobo5195]

Fluorinert is quite a bit bigger than water though

[BillA]

god you're quick bobo
lol
(notice I did not use the word molecule too)

[bobo5195]

meh bored and drunk is a happy posting combo

Compound bill, not molecule. my old chemistry teacher used to get mad about that.

[BillA]

eh ?
not gonna touch this less I appear an even bigger fool than I know I am

[ProHandyman]

Originally Posted by bobo5195

Compound bill, not molecule. my old chemistry teacher used to get mad about that.

Ohhhhh, read this:

One definition of a Molecular Formula is "a formula indicating the actual number of atoms of each element making up a molecule."1 In other words, the molecular formula must accuratly state the exact number of atoms of all of the elements in one molecule of the substance.

One definition of an Empirical Formula is "the formula giving the simplest ratio between the atoms of the elements present in a compound."2 In other words, in an empirical formula, you must find the ratio of atom to atom, in a molecule, and then reduce it.

Other Important Information:

The formulas for Ionic Compounds are empirical formulas.
A molecular formula is "a whole number multiple of an empirical formula."3
Converting to Emprirical Formula from Molecular Formulas is slightly more difficult than vice versa.


Information provided by: http://www.fordhamprep.pvt.k12.ny.us

Yikes! That makes my head hurt more! I think it kinda explains... must be a chemical engineer thing! lol

[bigben2k]

Originally Posted by bobo5195

...Compound ..., not molecule...

What's the diff?

[BillA]

so an azeotrope is not a compound ?

come on bobo, step up to the plate
(gonna lose that buzz in a hurry)

[BGP Spook]

My understanding of the difference between a molecule and a compound is mostly a quantitive thing. Example, we say there is a compound in a flask.

Edit: In chemistry a compound is pure.

[billbartuska]

Originally Posted by BillA

so an azeotrope is not a compound ?

come on bobo, step up to the plate
(gonna lose that buzz in a hurry)

Uh! right.

[bobo5195]

GCSE high school chemistry (ie crappy they still lie to us science) used to say molecule is a collection of atoms genrally made up with one type of atom. Compound is a collection of one or more different types of atom. its a pedantic point made by GCSE exams board that doesnt make an real sense in the real world but meh.

That buzz last me 13 hours bill

[BillA]

self medication is always fun

for me a molecule was a string of atoms of whatever, but 'connected'
a compound was a mixture of molecules 'not' connected
nothing to do with correct science of course

when I went to school in the UK I never passed even an O level, take it from there

[TerraMex]

still too lazy to google for "chemistry", eh?

http://chemistry.about.com/od/moleculescompounds/

[BillA]

see post above, lol
failed to find the distinction between the 2 on that pg however (good heading though)
??
I miss something ?

[nexxo]

Originally Posted by bobo5195

Fluorinert is quite a bit bigger than water though

Yeah, I considered this a few minutes after posting.

Still, I don't think I've heard of people losing water through thick-walled Tygon tubing. Can anyone comment on that?

[bobo5195]

I was only going on what bill said.

Thick wall should reduce evapouration rates but not all. Also thick tubing will take longer to kink. Combining these it may just slow things down to an acceptable pace, say 5 years from 5 months or something like that.

Off the top of my head (i wouldnt mind being proved wrong) tube thickness squared is tube pressure strength and say transpiration is linear with thickness. So a doubling of thickness is 8 times the protection against kinking. Though there are still bubbles to worry about.

[BillA]

agree w/bobo

[TerraMex]

ps : thinking about it, what about something like waterwetter than creates a layer of crap around, er, everything ? should be interesting to see if that correlates to decrease of transpiration.

or

[BillA]

never did with me, using silicone hose at that time

[Ruiner]

Originally Posted by BillA

if I wanted to post in baby talk I'd still be on OCF

That was funny enough to quote.

[BillA]

I guess my rep cannot get any worse, I'm well disliked on H