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Nitrogen to spray with?

31K views 106 replies 33 participants last post by  powerrodsmike 
#1 ·
Anyone noticed any diference using nitrogen to shoot their paint with? I can get a 230 bottle(biggest) for $16, so it's cheap enough if it makes a difference. I know I wouldn't have a water problem.
 
#27 ·
confused said:
they are starting to use nitrogen in automtive tires now. shop air in tires will be obsolete soon.
Considering that shop air is already 80% nitrogen, I'm struggling to understand the advantages (other than marketing and the silly green valve stem caps). As for the nitrogen being drier, well, what's the first thing you do when mounting a tire? Yeah, swab the beads...
 
#28 ·
Joe, I am with you on this one I have seen these big Nitrogen units for airing tires and I fail to see the advantages in spite of the claims of better fuel mileage (EVERY gimmick claims that!) and longer tire life. While MAYBE the rubber in the tire MIGHT last longer with no Oxygen inside I can not believe that tread life could be extended and since that is the end of most tires, not rubber deterioration, how the heck can tire life benefit? Maybe all this is true and someone can explain how but I remain highly skeptical at this point and I doubt that Nitrogen will ever completely replace air in tires. JMO and I am open to education on this one :)

Barrybomb, Now we are on to tires so I may have to start drinking with you :drunk:
 
#30 ·
61 chevy said:
I would venture to say the 260 + 260 cubic feet. ...So 260/12 ( my uneducated guess on cfm of hvlp gun )=21.666. So I would guess that you would have no more than 21 minutes of supply available at this rate. Although the actual time would be less if you figure in the effect of flow verses presure. It is a holiday weekend and I refuse to embark on such mathmatical formulations. :thumbup:
You know,I found a couple of tables for calculating the volume of gas in a compressed cylinder and found the volume of the Oxygen cylinder used in my Oxy-Acetylene torch setup (and probably the same size cylinder for Nitrogen,about 5' tall,called a K cylinder) 1.76 cubic feet-I would have figured more,but filled to about 3000psi, the one tank should last around 20 minutes at 12CFM @50psi. I had to do little estimation of a few factors but it should be close,it backs up the estimation by 61 Chevy above (nice job!).

That's 20 minutes(or slightly less) of trigger fully depressed,as if you just sat there with the trigger all the way down.Maybe someone with more painting experience than I could give an idea on about what percentage of the time during a paint job the trigger is down and the paint is flowing (not time spent moving around the car,getting position,starting and stopping etc.) Maybe someone could give you an example on how long it takes to lay down a complete coat on a particular car and for what percentage of that time the trigger is down and you can then figure on how far you can get on a tank.

The pressure to which the tank is filled by your supplier will also effect the entire equation of course.
 
#32 ·
It may be that painting with Nitrogen is not far fetched at all and apparently two tanks together would provide enough gas and maybe even one would be enough, there would of course be the expense of the manifold if more than one tank is used but these are not all that expensive. Not sure if a standard regulator would flow enough to power a HVLP gun but it probably would work for a conventional gun and maybe some of the better HVLPs. Maybe??
 
#33 ·
Nitrogen in tires is not a gimick. Aircraft tires use nitrogen as it is much more stable with temperature changes and pressure changes(altitude) If you filled an aircraft tire to about 150 PSI (some tires are inflated to over 200 psi) with normal air on the ground it could easily double at altitude and blow the tire up with catastropic results. on landing the heat generatred by landing friction and brake application is so high you get the same expansion problem. Nitrogen pressure in a hot tire is not much higher than a cold tire. Check your car tire in the morning, then after an hors drive in the summmer and you could see 5 psi difference easily. Race car tires need to be kept stable as they are balanced with tire pressure and the heat generated is alot more intense than in a passenger car.

I fail to see the benefit of using nitrogen in a painting application, the cost of a contract or purchase of a bottle can't be that much of a savings over a decent compressor. Plus it would be dangerous to displace all your breathing air with an inert gas. i can speak to that firsthand as we had an issue at work releasing nitrogen into a small room. luckily headashes were the worst ingury but it could have been much worse.
 
#34 · (Edited)
quote- [ If you filled an aircraft tire to about 150 PSI (some tires are inflated to over 200 psi) with normal air on the ground it could easily double at altitude and blow the tire up with catastropic results.


Uhh, I don't think so :confused: That kind of defies the laws of physics dose'nt it? The tire may tend to expand a tiny bit because the outside pressure will decrease but the pressure inside the tire can not increase unless you add more air, increase the temperature or decrease the size of the tire. In fact on a hot day, or most any day, the pressure would drop slightly instead of increasing because of the drastic temperature drop between ground level and 30,000 ft. I agree with you about the heat generated on landing but pressure increase with altitude? No way! I picked about 30,000 ft as an example because I assume you are talking about jets and plain air is of no concern at all in my Cessna 152 which will never see over 12,000 ft but lots of aircraft use plain air and go a hell of a lot higher than that without tire problems. :) As has already been pointed out Oxygen depletion would be of no concern in a paint booth or any painting area because ventilation is required anyway, like I said earlier the paint fumes and over-spray would reach toxic and blinding levels long before Oxygen depletion becomes a problem.
 
#35 ·
Hehe... Reminds me of the time we were driving from here (EL = 16 ft) to Colorado (EL = 8850 ft) and had a bag of chips in the trunk. When we got there, that puppy was swole up about 3x normal size, but never did blow!

Russ
 
#36 ·
That bag expanded because the pressure outside dropped, not because the pressure inside increased.(incidentally those bags are filled with Nitrogen to displace the Oxygen so the contents won't go stale :) ) At that altitude change the pressure dropped by a few psi and so the gas in the bag was allowed to expand and if taken higher it would have exploded but this would be due to the bag, unlike a tire, being unable to contain the few PSI difference and even at 50,000 ft it would not be enough to cause a tire to explode. To say that the pressure in an aircraft tire would double and result in explosion at altitude due to being inflated with air instead of Nitrogen is simply ridiculous. The difference in pressure change in a car tire using Nitrogen instead air because of heat build-up may very well be enough to make a difference in tread wear, I had not thought of that. I think it was about a year ago that someone asked about spraying paint with Nitrogen or CO2 because the location did not lend itself to using a compressor and now it has been asked again. There may be some legitimate reasons for the need for this and it does no harm to examine it since it seems anyway that it might be more practical than at first thought. If the cost could be held to less than $25 or so per job then in comparison to other costs it may not be too expensive, key word here being "if". Once the tanks are set up then refill would not be that costly and one would have zero problems with air line contamination and possibly even some other benefits (or maybe drawbacks?) that we have not covered yet.
 
#37 ·
I have been schooled! I had erred in my statement, the presure doesn't increse, the pressure differential increases. 4 psi differential can be a huge deal when you have a sudden pressure release. You are also correct in saying that the toxic elements of a paint job would outweigh the oxygen displacement from the nitrogen but why add an element if you don't have to. This is almost as funny as the guy who wanted to inject oxygen into his carb to get more power. If you can't afford a compressor you can't afford the paint and if you don't have the facility to support a compressor you probably shouldn't be painting either. Call me stupid but I don't see the point.
 
#38 ·
There is a whole lot of misinformation about nitrogen filled tires. For those who appriciate the math and engineering analysis, here's a link to debunk the whole marketing myth:

http://www.eng-tips.com/viewthread.cfm?qid=168616&page=1

To summarize, the FAA requires N2 filled tires on aircraft not due to expansion but to mitigate the chance of fire due to an overheated brake on landing. In addition, it is usually more convenient to drag a nitrogen bottle on a cart across the tarmac than to find a compressor and drag an air hose. Also, most aircraft tires are filled to 125 psi, which is at the high end for most small compressors.

As for the thermal expansion myth, it isn't due to air (which is already 80% nitrogen), it's due to water vapor. High pressure nitrogen bottles have considerably less water vapor than compressed air unless you have an outstanding drier in your compressor system. On the other hand, if you run through the math on the link I referenced, you'll find that for a normal, street-driven tire, the water vapor will make AT MOST a 0.5 psi difference as the tire is heated from room temp to 200 deg F. If you're worried about the water vapor in the air used to fill the tire, I'll again point out that the first thing you do when mounting a tire on a rim is to swab the beads. I'm willing to bet that puts way more water vapor inside the tire than any amount of compressed air.
 
#39 ·
joe_padavano said:
There is a whole lot of misinformation about nitrogen filled tires. For those who appriciate the math and engineering analysis, here's a link to debunk the whole marketing myth:

http://www.eng-tips.com/viewthread.cfm?qid=168616&page=1

To summarize, the FAA requires N2 filled tires on aircraft not due to expansion but to mitigate the chance of fire due to an overheated brake on landing. In addition, it is usually more convenient to drag a nitrogen bottle on a cart across the tarmac than to find a compressor and drag an air hose. Also, most aircraft tires are filled to 125 psi, which is at the high end for most small compressors.

As for the thermal expansion myth, it isn't due to air (which is already 80% nitrogen), it's due to water vapor. High pressure nitrogen bottles have considerably less water vapor than compressed air unless you have an outstanding drier in your compressor system. On the other hand, if you run through the math on the link I referenced, you'll find that for a normal, street-driven tire, the water vapor will make AT MOST a 0.5 psi difference as the tire is heated from room temp to 200 deg F. If you're worried about the water vapor in the air used to fill the tire, I'll again point out that the first thing you do when mounting a tire on a rim is to swab the beads. I'm willing to bet that puts way more water vapor inside the tire than any amount of compressed air.
Exactly. I have maintained that if there is any advantage to using bottled N2 to fill tires, it comes strictly from reducing the oxidation of the rubber inside the tire, thereby increasing life. However, the oxidation due to air is so slow, you would really have to park the car for long periods of time to realize the benefit. And, the exterior of the tire is exposed to air, so you are only half way there. Finally, you should be driving it and wearing the tires out before they oxidize.

To bring it back to painting, I think if your booth has proper ventilation, this would work. But again, I think the return on investment is minimal.
 
#40 ·
The tires of my Caterpillar 416 backhoe came filled from the factory with nitrogen, and the cat owner's manual advices to always use nitrogen only, to keep the rims from rusting, it's absolutelly dry, formula one tires are also filled with nitrogen to avoid changes in pressure, by the way my local kart club prohibits the use of nitrogen just to keep competition fair an lower costs, we race sudam motors wich are quite expensive.

Augusto
 
#41 ·
I just got my "Parts & People" newsletter today and there was an article on spraying with Nitrogen. Check out this link....Nitrotherm spray systems Haydell industries is distributinig them out of Lafayette La maybe new stuff in the US, but it looks like old news in Europe. Been used at collision shops as well as at the manufacturing level.

Very cool stuff.

Brian
 
#42 ·
nitrogen to paint with

I gotta chime in on this. Give every body my two scents. Nitrogen is harmless It is used daily by fire sprinkler companies two air up dry systems, because it expands at about one hundred two one.secondly for any one who would ever want to know nitrogen is the source and (I'M serious) that powers all of those neat little power tools in the operating room. Yes when they operate on you with all those neat little gadgets they are powered buy nitrogen. Compressed air would allow bacteria to grow. My father inlaw is an MD and I have had to work around it in hospitals before. The only side effects to using it to paint with would be supplying consistant volume and YES nitrogen is VERY cold when large cfms are released. ( you would have frost on your paint gun) Think i'm kidding Try it, the volume needed to run a paint gun would leave you with an ice cube in your hand. I'm for any one trying something new or the latest but this one wouldn't pay off to well for you. MY TWO CENTS (LOL)
 
#43 ·
I am sure it is more complicated than simply getting a nigrogen filled tank and putting an air hose on it to your gun. :) But the link that I have proved may have a little more to help understand it. I was at work when I found that and didn't have time to read it all. But the once over I gave it sounds like it is a pretty promising way to decrease a number of problems related to applying automotive finishes.

Now with the waterborne that is comeing our way...........

Brian
 
#44 ·
Watch the video at the link, VERY cool stuff!!! Not only is it great science/chemistry basics lesson it shows a nice application of paint as well. Very cool technology.

Brian
 
#45 ·
MARTINSR said:
Watch the video at the link, VERY cool stuff!!! Not only is it great science/chemistry basics lesson it shows a nice application of paint as well. Very cool technology.

Brian
I liked the way all those plus (+) signs just sprayed out. :thumbup: I think clovers would be a better design though.

I wonder if a guy could do the same with Co2..
He could toss a chunk of dry ice in his pressure pot and as it dissolved, it would pressurize the inside of the pot and he could spray away... ;) (I think you'd need a big pot though....)

Is Co2 as flammable as nitrogen? I read somewhere that it was.. :eek:
(all kinds of disinformation out there....cain't never be too sure of what ya read)

Nitrogen sure would be good for spraying filled polyester surfacing primers..That tape peel test was something else...

I wonder how the final hardness of the paint is affected, doesn't the action of spraying paint have a tendancy to mix oxygen in and hasten cure and cured hardness levels?

Later, mikey
 
#46 ·
oldred said:
quote- [ If you filled an aircraft tire to about 150 PSI (some tires are inflated to over 200 psi) with normal air on the ground it could easily double at altitude and blow the tire up with catastropic results.


Uhh, I don't think so :confused: That kind of defies the laws of physics dose'nt it? The tire may tend to expand a tiny bit because the outside pressure will decrease but the pressure inside the tire can not increase unless you add more air, increase the temperature or decrease the size of the tire. In fact on a hot day, or most any day, the pressure would drop slightly instead of increasing because of the drastic temperature drop between ground level and 30,000 ft. I agree with you about the heat generated on landing but pressure increase with altitude? No way! I picked about 30,000 ft as an example because I assume you are talking about jets and plain air is of no concern at all in my Cessna 152 which will never see over 12,000 ft but lots of aircraft use plain air and go a hell of a lot higher than that without tire problems. :) As has already been pointed out Oxygen depletion would be of no concern in a paint booth or any painting area because ventilation is required anyway, like I said earlier the paint fumes and over-spray would reach toxic and blinding levels long before Oxygen depletion becomes a problem.
holy crap oldred, the service ceiling of a cessna 152 is 12,000 at best. density-altitude usually = a lot less. i never had mine over much more than 6000'. are you wiley post re-incarnated... come back to earth and keep posting all those welding threads. don't leave, we all need you.. :D :D :D
 
#48 ·
powerrodsmike said:
Is Co2 as flammable as nitrogen? I read somewhere that it was.. :eek:
(all kinds of disinformation out there....cain't never be too sure of what ya read)
Yes, CO2 is a flammable as N2. Both are considered non-flammable. For that matter, both are used to suppress fire in one way or another.

And this is why you have to be extremely careful around either of them. Basically, our body oxidizes food using the O2 from the atmosphere. In essence, we are doing a "slow burn" in order to live. N2 and CO2 have a tendency to displace the O2 in the atmosphere, thus preventing our slow burn. No O2, no life. Hard to enjoy a nice paint job in that state.

Maybe you are thinking of H2 (the gas, not the vehicle). Think Hindenburg.
 
#49 ·
muhself said:
Is Co2 as flammable as nitrogen? I read somewhere that it was..
(all kinds of disinformation out there....cain't never be too sure of what ya read)
redsdad...I was goofing off a little :p


Ok, here's what I wonder...why aren't paint gun companies trying to develop airless methods of spraying paint?

It is an accepted method of coating application in the fiberglass industry and house painters all use airless sprayers.

Absolutely no thinning is necessary, so less solvents go into the air, and viscous materials are routinely sprayed at wet film thicknesses of .015" or .020". .

It puts most all of the paint on the part too, without fancy gas generators.

Later, mikey
 
#50 ·
Mikey, in the early days of VOC rules (after the "Clean air act" of 1990 in Ca) the equipment manufacture did EVERYTHING to try to make a system to beat it. "Throwing" the paint on with an airless was just one of them. They even thought that some day we would be applying the finish in a big applique vinyl sheet! Then they figured that the auto manufacture would paint the parts and we wouldn't even have the rights to paint.

The early HVLP guns were a living hell! And the equipment was just the beginning, how about the products? HOLY HELL, they just DROPPED the solvents out, that was their solution to the problem, no VOC in the product, no VOC problem. HOLY CRAP, they made the friggin crappiest junk to work with ever. And this was dumped on us in just a few years. Lacquer was dropped, urethanes were "new", it was hell.

But after all is said and done, there are some damn good products out there and damn good equipment to apply it.

Brian
 
#51 ·
techron said:
holy crap oldred, the service ceiling of a cessna 152 is 12,000 at best. density-altitude usually = a lot less. i never had mine over much more than 6000'. are you wiley post re-incarnated... come back to earth and keep posting all those welding threads. don't leave, we all need you.. :D :D :D


Never said I have had it that high, That little Lycoming sure would be doing some gasping but we like to think big don't we? :D
 
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