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08-06-2020, 07:30 PM
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#21
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PhD, Common Sense
Join Date: Feb 2017
Location: Fairborn, OH
Posts: 1,384
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After the winter, I need to add two pounds to each tire.
Two pounds in one year.
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08-06-2020, 07:56 PM
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#22
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by Larry-NC
The oxygen molecules in air are BIGGER than nitrogen and should diffuse (leak) through the tire MORE SLOWLY than nitrogen molecules.
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Oxygen is actually a little smaller. Has nothing to do with the molecular weight hence the reason CO2 diffuses through tires really fast. CO2 is MUCH smaller than both Nitrogen and Oxygen. When I fill my bike tires with a CO2 cartridge after a flat on a bike ride, the tire is completely flat by morning.
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08-06-2020, 08:05 PM
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#23
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Senior Member
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 9,458
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Pulling my chain?
Quote:
Originally Posted by babock
Oxygen is actually a little smaller. Has nothing to do with the molecular weight hence the reason CO2 diffuses through tires really fast. CO2 is MUCH smaller than both Nitrogen and Oxygen. When I fill my bike tires with a CO2 cartridge after a flat on a bike ride, the tire is completely flat by morning.
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C'mon, Babcock, quit pulling my chain. Classical physics dictates the size of the molecules as corresponding to the number of (heavy) protons/neutrons in the nucleus. Atomic weight 16 is heavier than 14.
You will have to explain your theory better to convince me.
__________________
Larry
"Everybody's RV is not like your RV."
"Always take pictures with the button on the right."
"Always bypass the water heater before opening the low-point drains."
Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
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08-06-2020, 08:24 PM
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#24
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Senior Member
Join Date: Aug 2013
Posts: 7,916
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__________________
2017 Puma 297RLSS
2005 Ram 2500 4X4 diesel SMOKER!!
I love puns, irony and tasteless jokes...
born in Texas.... live in Arkansas
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08-06-2020, 08:27 PM
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#25
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PhD, Common Sense
Join Date: Feb 2017
Location: Fairborn, OH
Posts: 1,384
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Quote:
Originally Posted by Iwannacamp
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Thanks. Facts are spectacular things.
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08-06-2020, 08:42 PM
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#26
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Senior Member
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 9,458
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Good reference!
Quote:
Originally Posted by Iwannacamp
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Good reference. I concede that the Oxygen atom is smaller than the Nitrogen atom.
I found this statement, too:
Quote:
Nitrogen molecules (N2) are larger than oxygen molecules (O2) so therefore, pure nitrogen will permeate the walls of your tires less than oxygen molecules.
But by how much?
Well, a nitrogen molecule measures roughly 300 picometers while an oxygen molecule measures 292 picometers. That’s only a 2.6% difference in size. One picometer is equal to one trillionth of a meter (1 m / 1,000,000,000,000).
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Nitrogen or Air?.
__________________
Larry
"Everybody's RV is not like your RV."
"Always take pictures with the button on the right."
"Always bypass the water heater before opening the low-point drains."
Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
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08-06-2020, 09:01 PM
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#27
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Senior Member
Join Date: Jul 2012
Location: Northern Nevada
Posts: 252
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I've got four tire gauges and they all will read 2 to 4 lbs. different....I mark the one for the trailer with a sharpie so I don;t get confused, or more confused....
__________________
Dave...Northern Nevada
2018 Rockwood 8299bs
2007 GMC 2500HD Diesel SLT short bed w/gravity flow75 gallon Fuel Tank.. Cat delete
Firestone Airbag Ride Rite system
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08-06-2020, 09:24 PM
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#28
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Brake is on left
Join Date: Jul 2019
Location: USA
Posts: 1,095
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Quote:
Originally Posted by paverdave
I've got four tire gauges and they all will read 2 to 4 lbs. different....I mark the one for the trailer with a sharpie so I don;t get confused, or more confused....
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Lol. I am with ya. It is more about uniformity with me. Otherwise I would be constantly adding or removing pressure every time I check a tire.
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08-06-2020, 09:57 PM
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#29
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Pulling your chain? Started out as a chem major.
Quote:
Originally Posted by Larry-NC
C'mon, Babcock, quit pulling my chain. Classical physics dictates the size of the molecules as corresponding to the number of (heavy) protons/neutrons in the nucleus. Atomic weight 16 is heavier than 14.
You will have to explain your theory better to convince me.
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08-06-2020, 09:58 PM
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#30
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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LOL...ok!
Quote:
Originally Posted by Larry-NC
Good reference. I concede that the Oxygen atom is smaller than the Nitrogen atom.
I found this statement, too:
Nitrogen or Air?.
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08-07-2020, 07:06 AM
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#31
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Senior Member
Join Date: Jan 2020
Posts: 712
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One thing to keep in mind about nitrogen vs air is many air compressors that we use do not dry the air. Nitrogen sources are dried since they are isolating one gas. If you use clean, dry air (I forget what the humidity spec is for dry air) you will see similar performance to nitrogen.
Industrial compressors use heaters and desiccant to dry the air. My shop compressor uses neither.
__________________
Hobienick
2022 Grand Design Imagine 2800BH
2020 Rockwood Roo 19 (Sold Jul 2022)
2012 F150 SuperCrew Ecoboost
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08-07-2020, 09:15 AM
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#32
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Senior Member
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,288
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The Nitrogen versus Air discussions ususlly result in a run on popcorn at store shelves.
Nitrogen has it's followers just like food supplements have their ardent supporters even when science has shown the ones they praise have zero value.
The good news is that Nitrogen causes no harm unless you have to pay for it.
When it comes to tires about the only application where it is a clear benefit is in aircraft tires subjected to extreme temps during landing. There it's utilized more as a fire suppressant.
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)
"You only grow old when you run out of new things to do"
2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change )
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08-07-2020, 09:22 AM
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#33
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Senior Member
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,288
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Quote:
Originally Posted by hobienick
One thing to keep in mind about nitrogen vs air is many air compressors that we use do not dry the air. Nitrogen sources are dried since they are isolating one gas. If you use clean, dry air (I forget what the humidity spec is for dry air) you will see similar performance to nitrogen.
Industrial compressors use heaters and desiccant to dry the air. My shop compressor uses neither.
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Most tire stores use various methods to remove water fron their compressed air. Coalescing filters, refrigerated driers, and sometimes just auto drains from compresser tanks and shop air lines where it condenses as it cools. Any moisture in air entering a tire has little or no effect on tire performance.
Time to buy more popcorn-----
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)
"You only grow old when you run out of new things to do"
2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change )
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08-07-2020, 10:30 AM
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#34
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by TitanMike
Most tire stores use various methods to remove water fron their compressed air. Coalescing filters, refrigerated driers, and sometimes just auto drains from compresser tanks and shop air lines where it condenses as it cools. Any moisture in air entering a tire has little or no effect on tire performance.
Time to buy more popcorn-----
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In my garage, I have a auto water drain on my compressor as well as a long length of hose before it his a water separating filter.
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08-07-2020, 10:48 AM
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#35
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Senior Member
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,288
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Quote:
Originally Posted by babock
In my garage, I have a auto water drain on my compressor as well as a long length of hose before it his a water separating filter.
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When took the position at the company I retired from I oversaw, among many other things, construction of the shops. Nobody ever bothered to read the recommendations for air system design put out by compressor manufacturers. They let the plumber who built the air distribution system just do his thing. Most plumbers just plumb water lines and they would just go from compressor to point of use in as straight a line as possible. Rather than low point drains they just sloped the lines so all condensate drained back into the compressor.
Proper design called for a "loop" around the shop near the ceiling with an overall slope towards the farthest corner from the compressor where a low point drain would be installed. All "taps" for point of use were to be in the form of a Tee pointing UP and then using two 90's routed back down to the point of use. Like an inverted P-Trap. This trapped all water in the main air line and it would than fall to the drain point where it didn't re-join the fresh air from the compressor.
The "loop" also acted as an aftercooler which precipitated a good amount of moisture discharged from the compressor. It also provided two separate paths from the compressor to the point of use so pressure drops were minimal. Important when seating a tire on tire changers on a busy day.
After implementing this change in new stores other dealers started retrofitting their stores. Made a big difference in air tool and tire changer maintenance/repair too.
In climates with high humidity we added refrigerated driers but most of the rest of the country found air/water separators more than adequate.
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)
"You only grow old when you run out of new things to do"
2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change )
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08-07-2020, 10:55 AM
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#36
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by TitanMike
When took the position at the company I retired from I oversaw, among many other things, construction of the shops. Nobody ever bothered to read the recommendations for air system design put out by compressor manufacturers. They let the plumber who built the air distribution system just do his thing. Most plumbers just plumb water lines and they would just go from compressor to point of use in as straight a line as possible. Rather than low point drains they just sloped the lines so all condensate drained back into the compressor.
Proper design called for a "loop" around the shop near the ceiling with an overall slope towards the farthest corner from the compressor where a low point drain would be installed. All "taps" for point of use were to be in the form of a Tee pointing UP and then using two 90's routed back down to the point of use. Like an inverted P-Trap. This trapped all water in the main air line and it would than fall to the drain point where it didn't re-join the fresh air from the compressor.
The "loop" also acted as an aftercooler which precipitated a good amount of moisture discharged from the compressor. It also provided two separate paths from the compressor to the point of use so pressure drops were minimal. Important when seating a tire on tire changers on a busy day.
After implementing this change in new stores other dealers started retrofitting their stores. Made a big difference in air tool and tire changer maintenance/repair too.
In climates with high humidity we added refrigerated driers but most of the rest of the country found air/water separators more than adequate.
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Fortunately, I am in a dry climate. I still needed dry air since I used to do some auto painting. Of course my air tools also need it but it's really necessary when you paint.
I get water out of my tank all the time. My auto tank drain is set to go off every hour or so.
I know a lot of friends that never drain their tanks. Some day they may have an unpleasant experience when their thank blows up.
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08-07-2020, 11:21 AM
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#37
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Senior Member
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 17,288
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Quote:
Originally Posted by babock
I know a lot of friends that never drain their tanks. Some day they may have an unpleasant experience when their thank blows up.
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Tanks rarely blow up from rust. They just start leaking like a sieve. The noise eventually gets the owner's attention and they either buy another compressor or replace the tank.
I saw a compressor in a body shop back in the 70's where the owner just screwed "boiler plugs" into the rusted holes. Compressor was on a "shelf" above the door to the office from the shop. State Dept of Labor inspector saw it and tagged it as unsafe. There were about 7-8 of these screw in plugs (a large sheet metal screw with a washer and gasket) screwed into the bottom of the tank. Inspector pointed out that a good slam of the door might trigger the release of the plugs and whoever was unlucky enough to be under it would be "shot" through the top of their head (possibly more than once).
Clearly a lack of future thinking.
__________________
"A wise man can change his mind. A fool never will." (Japanese Proverb)
"You only grow old when you run out of new things to do"
2018 Flagstaff Micro Lite 25BDS
2023 f-150 SCREW XLT 3.5 Ecoboost (The result of a $68,000 oil change )
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08-07-2020, 12:22 PM
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#38
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Senior Member
Join Date: Jul 2017
Location: California
Posts: 7,616
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Quote:
Originally Posted by TitanMike
Tanks rarely blow up from rust. They just start leaking like a sieve. The noise eventually gets the owner's attention and they either buy another compressor or replace the tank.
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I have a mechanical engineer friend who does expert witness testimony. He actually worked a case where A craftsman compressor did explode and Sears was being sued.
I agree though, most of the time they will just start to leak,
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08-07-2020, 01:09 PM
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#39
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Senior Member
Join Date: Sep 2015
Location: North Alabama
Posts: 1,140
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Not a fan of the nitrogen fill money maker. But for this reason.....
Lets assume for a moment the argument that nitrogen fans propose that the oxygen component in "air" leaks out. So you fill your tire with regular air....78% nitrogen, 21% oxygen.
Then the oxygen mysteriously leaks out and only nitrogen remains. Lets just say we have that 21% volume "gap" to fill back up. So you fill that gap with air (78%/21% mix).
Now the mixture in the tire has become about 94% nitrogen since the missing volume is 3/4 filled with nitrogen in regular air. The remaining percentage being oxygen and some trace gases. One more time of the small (about 4%) of oxygen leaking out and being filled with regular air (again 78% nitrogen) would theoretically have your tire filled with as much nitrogen as paying for a "pure" nitrogen fill from scratch .
__________________
2016 F350 CC Dually Powerstroke 4x4
2014 Cedar Creek 34RLSA w/Level Up
2007 HD Ultra Classic 103
USS Pyro AE-24 WestPac MM2 '71-'75
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08-07-2020, 01:18 PM
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#40
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PhD, Common Sense
Join Date: Feb 2017
Location: Fairborn, OH
Posts: 1,384
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You’d think it might work that way. I don’t know why it doesn’t, but (from my experience) it doesn’t.
We had a truck with nitro in the tires. We hardly ever had to “air” up the tires. Due to an accident we replaced that truck with the then-current version of the same truck. Nitro in the tires was not available as an option. We were and are airing up those tires (and the two sets we have replaced them with) constantly.
Our current trailer came with nitro. We fill them once a year with a pound or two. (This year, as I reported yesterday, it was 2 lbs.)
Not saying what is best. That is for you to decide. Just relating the facts of my personal experiences.
Oh, and we have never paid a penny for nitro.
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