A Rainy Day Question

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Started raining off and on last evening, and it's continuing today.  The "shop" is a little dampI never like to weld up tubing when there's any moisture in it.  Actual liquid, not humidity.How long before any small amount of moisture is absorbed by the steel when enclosed by welding it shut.  Or does it remain there forever.  I would assume that any internal oxidation caused by the moisture would "consume" the moisture on a molecular level  (water bein' H20 and all)Hate losing a whole day to intermittant rain.  The surface of the steel tubing dries pretty fast, but it takes longer for the inside to dry.  And I'm behind schedule"Any day above ground is a good day"http://www.farmersamm.com/
Reply:I coulda sworn you said you were gonna keep this build confined to 1 thread? Just playin bud Might be a stupid suggestion/ not what you want to know, but maybe just weld it up then drill a SMALL hole or 2 for any moisture/water left inside to drain out of?Just a suggestion and possibly a stupid idea.-adamBeer is proof that god loves us and wants us to be happy!
Reply:Not a stupid suggestion at allI usually leave a small unwelded pinhole/gap at the bottom of fully "sealed" tubing for the same purpose.  I never assume my welds are air/water tight.  I've seen severe rust thru, and bursting due to ice expansion in "sealed" tubing.I do it mostly on stuff that's always in the vertical position, and that maybe can collect serious amts of rain water over the years.THIS ISN'T MY PROJECTsorta kindaIt's of general interest"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by Jst_Spark_It09 just weld it up then drill a SMALL hole or 2 for any moisture/water left inside to drain out of?-adam
Reply:Originally Posted by farmersammTHIS ISN'T MY PROJECTsorta kindaIt's of general interest
Reply:Originally Posted by TEKEasier than that, just grind a small notch on one side of the tube and then, when welding, dont weld that notch closed...easier than drilling, and it gets the drain point closer to the adjoining tube.
Reply:But back to the original question, if I put a teaspoon of water inside a 10 foot pipe and sealed up the ends --------------- how much damage and for how long would that teaspoon of water cause damage?
Reply:if no O2, \can it rust ?
Reply:Don't worry about it...It will take more time for the tubing to go away from the inside out than you will live......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:If iron is heated to redness and steam is passed over it, iron oxide will form and H2 will be given off. At room temperature, this might happen slowly and to a small degree, or it might not; that depends on salts in the water, the coating on the steel, etc. If more oxygen is available and rusting does eventually start (likely with excess O2 present), it will continue so long as the O2 is available. If no new O2 is present, it won't continue even if it starts.Thus, if you remove all the liquid, and probably even if some is still present, a fully sealed tube should be be the most resistant to inside rust.
Reply:Sam,I am thinking you are thinking allong the lines of a fence post, my question for you is, is the other end of the pipe sealed as well? If the bottom is in the dirt, then there will always be moisture in the pipe anyway. I'd say turn on the welder, and get it done.
Reply:Originally Posted by Oldiron2If iron is heated to redness and steam is passed over it, iron oxide will form and H2 will be given off. At room temperature, this might happen slowly and to a small degree, or it might not; that depends on salts in the water, the coating on the steel, etc. If more oxygen is available and rusting does eventually start (likely with excess O2 present), it will continue so long as the O2 is available. If no new O2 is present, it won't continue even if it starts.Thus, if you remove all the liquid, and probably even if some is still present, a fully sealed tube should be be the most resistant to inside rust.
Reply:Originally Posted by Oldiron2If iron is heated to redness and steam is passed over it, iron oxide will form and H2 will be given off. At room temperature, this might happen slowly and to a small degree, or it might not; that depends on salts in the water, the coating on the steel, etc. If more oxygen is available and rusting does eventually start (likely with excess O2 present), it will continue so long as the O2 is available. If no new O2 is present, it won't continue even if it starts.Thus, if you remove all the liquid, and probably even if some is still present, a fully sealed tube should be be the most resistant to inside rust.
Reply:Originally Posted by weldbeadbut the sealed tube is full of air.......
Reply:Originally Posted by farmersammStarted raining off and on last evening, and it's continuing today.  The "shop" is a little dampI never like to weld up tubing when there's any moisture in it.  Actual liquid, not humidity.How long before any small amount of moisture is absorbed by the steel when enclosed by welding it shut.  Or does it remain there forever.  I would assume that any internal oxidation caused by the moisture would "consume" the moisture on a molecular level  (water bein' H20 and all)Hate losing a whole day to intermittant rain.  The surface of the steel tubing dries pretty fast, but it takes longer for the inside to dry.  And I'm behind schedule
Reply:The hydrogen thing Oldiron...........I wonder if that was the explosive gas that caused a few flash fires when older implements and industiral equipment were drilled/cut into.  I recall some articles about shavings and scrap being used for ballast inside sealed compartments.I'm sure some of you guys remember the thread."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Leaving a hole may not be the thing to do, ever see the zinc(I think) anodes that bridges have on them, and their is even a small electrical deionizer box you can buy for cars that does not allow for the ionization of exposed metal, been out a long time.Best way is to probally try purge all the moisture with a torch, and use weld through primer on anything else.Might have to buy primer the case....it is a legitimate worry.
Reply:Originally Posted by BoostinjdmBut it's a finite amount....Once the rust begins and the oxygen is used up, the rusting will stop.  That is, if there is even enough oxygen to get the process kicked off in the first place.
Reply:I generally have two ways I go.  Sealed (as far as I can tell), and well vented.  If I can't fit my thumb in the hole, it isn't vented well enough.  I have seen a lot of things (built by others) that have a small hole drilled in them or a small spot left un-welded on a joint so it could "breathe".  That small hole eventually either plugs up with rust/dirt, or becomes a big hole due to rust.Sam, you got the facilities.  Why don't you do an experiment.  Clean up a nice patch of dirt next to a building or something where it will get dripped on when it rains.  Weld up half a dozen tubes with caps.  Seal one, drill a small hole in one, drill a big hole in one, and leave an un-welded spot on one.  Throw them down on the dirt and leave them lay till next spring.  Then you can throw them in the saw to cut them in half and see what the results are.  As far as well vented tubes go.  I've got a stack of tubing that's been sitting on boards over a dirt floor in my steel building with no door.  Snow blows in on them in the winter and sometimes rain drips through screw holes in the roof.  They been there for about 4 yrs or so undisturbed.  I can go pick up any one of them and saw it in half and have perfectly clean tubing inside.  If you don't believe me, look at my trailer thread.  That is some of the tubing I'm talking about.  There is a pic there where I hole sawed the frame for lights and you can see the inside of the tube for yourself.  Now I'm rambling...I think that's enough for tonight.EDIT....here is the pic.  I wire brushed the outside of the tube, but with the inside, what you see is what you get.  Look inside the three holes.... Attached ImagesLast edited by Boostinjdm; 10-10-2009 at 03:22 AM.My name's not Jim....
Reply:I second the experiment idea. Check back in a couple years!Here in the rust belt, I sometimes end up using channel where I would like to use tubing just for the whole rust prevention thing.
Reply:Originally Posted by prop-doctorif no O2, \can it rust ?
Reply:Backpurge with argon just before sealing end....That's extreme, but may work.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:I dont know what you're building, samm, is this referring to the 3 prong rake?  How bout vent all the welds, and after the whole thing is welded, dump some WD40 and let it slosh around?I might be talking out of my *** here..
Reply:Well iron in the presence of an oxygen molecule (O) can = rust, that's a known. It's the disassociated or lone O molecule that is the culprit. Correct?  However the free air O2 we are all familiar with the O2 is a fairly stable little guy so if there was such a thing as an O2 environment with 0% humidity the rusting process would be a lot slower than any of us would want to wait & watch for. H2O being less stable as far as a source of the oxygen molecule (O), generally plentyfull and air without some degree of moisture unheard of in our everyday environment we have come to the conditioned association of iron + moisture = rust. Moisture and rust are what we see most of so that's what I have to go with as far as what I worry about the most.With that we know that unprotected iron exposed to humid air equals rust, iron exposed to condensate moisture equals even more rust, annnnndddd iron soaking in clean pure water equals more (?) or less (?) than the previous two conditions. They say that iron objects submerged in deep cold water don't rust as much. I am assuming that's because the density and cold temperatures reduce the availability of the free O molecules and retard the effect. That could be a bad azzumption too. I don't really worry about that either. If you lose a trailer in the bottom of Lake Erie rust isn't your big issue.So reworded, iron is the source of the FE, moisture is the main source of the O guy. My question is == is the total reaction limited to the volume of the source of the O molecule as in a one time reaction? In this case one teaspoon of water in a sealed tube would cause less rust than one cup and so-on. OR can it be a reocurring reaction using the same O molecule over and over slowly eating away at all the iron available? In this case the volume of water would only affect the speed of the reaction and not the amount of reaction/rust. BTW I don't want anybody lose a bunch of sleep trying to answer this qusetion, I dern sure won't.  Anytime before I die would be good tho.
Reply:This is a nonsensical question.   Seal the dam tubes off, at some point the chemical reaction (which is what rust is), will either run out of water, or run out of oxygen, at which point the chemical reaction stops.   Unless you leave a hole, or holes, that allow MORE water, or salts, or oxygen, in, I have NEVER, seen a tube properly closed off, rot from the inside out.  ANY tubes that rotted from the inside out, always had another way for water, salts, and oxygen, to find a way in, but not out.farmersamm said:I suppose it was kind of an esoteric question.esoteric means- intended for or understood only by a particular groupjsfab said:This is a nonsensical question.nonsensical means-lacking intelligable meaningI think I see what has happened here.all definitions provided by the good folks at thefreedictionary.com. All confusion provided by oklahoma cattle farmer. Any following chaos instigated by one guy with nothing to do.Ranger 250 GXTSmith Gas Axe
Reply:It's all sealed up now anyhow  In 20 or so years I might get the answer if it rusts thru.I did run a few QTips thru it before final welding, just to be on the safe sideThe smoke from the flux coating will be in there for eternity, like a time capsule"Any day above ground is a good day"http://www.farmersamm.com/
Reply:I misused "esoteric"  I suppose I meant something to be bounced around for S&G's."Any day above ground is a good day"http://www.farmersamm.com/