PeeWee2000
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A few unconventional uses for polyethylene tubing
Hello Mad scientists I'm new here and figured I would jump in with my opinion on polyethylene tubing and that is that it is an invaluable resource for
those on a budget!
First is an example of how it can be used to prevent breaking your barbs off of your condensers (of course some nice latex tubing is an easier way
but its a little bit pricier)
The things you will need are some 1/2" and 3/8" OD Polyethylene tubing from your local hard ware, a propane torch a lighter (for the torch) and a
couple of stainless steel hose clamps and your barbed glass ware of course
In order to get the tubing to fit on the barbs of your glassware you will need to heat the tubing to soften it up, this only takes 2-3 seconds when
using a torch and 4-5 if just using a normal lighter, make sure to rotate the tubing to evenly heat it. For my liebig condenser I am using the 1/2"
tubing, I have found on some gas adapters that 3/8" is nessecary because of smaller barbs but the majority of my equipment fits 1/2" tubing so be sure
to check what size is better for your equipment before you try this.
After you quickly heat the tubing firmly place it over the barb, it should not take much force at all if properly heated.
Now you should have something that looks like this. In my experience just the friction fit is enough to keep it water tight but if you are paranoid or
have a bunch of extra hose clamps feel free to use one.
Now the most convenient property of polyethylene tubing I have discovered is that the next smallest size slides right into the next size up perfectly,
but it does leak without a hose clamp. This being said I can easily connect and disconnect my water pump from my condenser by using this property to
my advantage. The larger tubing in the picture is 1/2" OD and the smaller tubing is 3/8" OD.
Now just hook up a cheap little fountain pump and wallah!
This being said my basic rule of thumb with this tubing is that if it looks like it will fit it probably will, that being said here are two other
things i have found it useful for. First being all those old bunsen burners that you probably have if youre working on a budget. And conveniently the
1/2" tubing slides right over the regulator with the burner tip unscrewed and makes a nice tight fit.
The second being for vacuum tubing seeing as how it goes straight onto the barbs of glassware so you can directly hook it up to your vacuum take off.
I have found that this tubing is capable of holding a vacuum for at least a couple minutes with the pump/aspirator turned off, gunking up the lines
with some silicone or petroleum jelly (or vacuum grease if you have some laying around) before clamping the hose can help but isnt nessecary.
I hope someone gets some use out of this post, if anybody has any questions or comments I would love to hear input or even see other people that
like\use my ghetto style  I have since upgraded to better equipment but figured
people starting out might find this useful so enjoy!
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bfesser
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Welcome to ScienceMadness, <strong>PeeWee2000</strong>! This just might be the best first post I've seen to date—content rich,
well written, in the correct sub-forum, <em>pictures</em>. Thanks for the contribution, and please keep up the good work.
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Blue Matter
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neat ideas but I learned if water is left a long time in the tubing it becomes more flexible and slimy not very fun to handle gets all over your hands
and smells strange
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Metacelsus
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I've had the same experience with the sliminess when using it for condenser hoses. Also, it doesn't hold up well to corrosive gasses. I naively used
it in a chlorine generator and somehow the previously clear tubing became cloudy and inflexible. Otherwise, I agree that polyethylene tubing is the
amateur chemist's friend.
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PeeWee2000
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Blue matter, I believe you are referring to latex tubing everything you described does happen to latex tubing. Unfortunately latex tubing does not
handle time well as you said, it is prone to cracking if left out in a dry area for a long time and becomes very slimy if left wet for too long as
well as it being rather pricey which is why I started this post . That being said
latex is still great if you dont mind paying a little extra to get it and take a little extra time to properly store it when you are done usnig it.
Polyethylene tubing on the other hand stays good basically forever as long as you don't leave it in the sun for days on end but on the bad side it is
very stiff, uncooperative and does not make a nice seal as easily, however when used properly it works just as well as latex.
Here is an example of some old tubing with bad cracking.
Here is an example of the slimey tubing that I believe blue matter was referring to, the white faded area had been floating in water for a couple
hours and the dark yellow area was face up in air.
Thank you bfesser, I was hoping to make a good first impression and I plan on posting any other start up tips I dont see already posted on the fourms.
Cheddite to my knowledge polyethylene tubing should be able to stand up to chlorine gas but it is listed in the good to fair resistance area so I
imagine it takes a toll over time. Here is the chemical resistance chart for the specific brand of tubing I use, specifically on page 14. http://media.wattswater.com/PL-Tubing.pdf
Also Cheddite are you referring to vinyl tubing? Polyethylene tubing is supposed to always be foggy and rather inflexible. I personally have never
used vinyl tubing so I am not too knowledgeable about it.
[Edited on 13-7-2013 by PeeWee2000]
[Edited on 13-7-2013 by PeeWee2000]
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Blue Matter
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I used some Polyethylene tubing on a vacuum adapter bubbling some NO2 gas out while synthesizing WFNA and exact same thing happened to it as with the
latex tubing you showed in above post. I think its just one of those things that will eventually happen if the tubing is used long enough or in odd
circumstances.
on another note I used some polyethylene tubing to make some home made gas wash bottles out of some fittings and Gatorade bottles they need to be in a
bit of water bath or they will melt, though not ideal I know but at the moment I don't have much glassware for other improvised gas wash bottle
setups.
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PeeWee2000
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Ahh yes nitric acid and the accompanying fumes are generally very rough on just about all types of plastic except fluoropolymers. The tubing
definitely has its limits thanks for pointing that out. Also kudos I have a home made gas washer for removing sulfur dioxide out of gaseous mixtures
made from PVC and a couple fittings, I plan to make a post on how to make one eventually as it is extraordinarily useful and versatile also its not
too pricey either . But heres a picture to give you an idea of what it looks like
until then.
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Blue Matter
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I made a improvised 90 degree tubing inlet adapter out of a broken vacuum adapter with a bit of spotty glassblowing.
I will edit this post with some pictures tomorrow with some things I thought up
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12AX7
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PE will be much more stiff than latex rubber, making it better for vacuum; in Organic lab, that always annoyed me!
Tim
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annaandherdad
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This is very useful information, thanks to everyone.
Any other SF Bay chemists?
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