when mig welding verticly. do you weld from the top to the bottom or bottom to the top?
456317
Im a perfect welder but i have no idea what a mig weld is
812948
For certain type of work TIG is required, like welding chrome moly for some racing organizations. Intricate work, like gunsmithing is also well suited to TIG. TIG is used by many auto restorers who prefer a more precise, perfect finish that requires little to no finish work.   TIG is most similar to gas welding in technique, so if you've done oxy-fuel welding, TIG should be a natural transition. \n\nIf you are looking to weld professionally Start with Mig and Tig then is a much easier task to perform\n\nMIG is required by law and by insurance companies in many localities for structural repair of automotive frames. MIG is also much easier to learn and faster to weld.  For doing other types of welding,   like sheet metal, it can be a matter of personal preference. For an auto body repair shop or a novice welder, a MIG is a good, practical all-around welder.
691119
Follow the same safety rules for welding stainless as for welding anything else.  You don't say if you are arc-welding, gas-welding or MIG- or TIG-welding, but you shouldn't be breathing the fumes whatever method you are using. The most toxic gases are likely to come from impurities in the metals you are welding rather than the welding gases themselves.\n\nShame on your new employer for assuming you had the appropriate safety training, or shame on you for giving the impression you did!
1050579
The technique is called Post Weld Heat Treatment (PWHT for short). \n\nAdam the Engineer has got it wrong (sorry Adam) and BikerwookieJim has got it almost right.\n\nThe only flaw in his answer is that you CAN rework a piece after PWHT, but you have to repeat the PWHT after the rework. The cost of doing PWHT is high and can be very high for large pieces (like in ship building), so you try to do it only once.\n\nPieces that have undergone PWHT are usually marked as such so that nobody does any rework which (as BikerwookieJim said) would leave a week point prone to failure.
1104009
Because the pulp ascent in the bottom
960394
Look up:\n\nwww-WeldingAnswers.com
788532
Is it x*(e-2) or x^(e-2)?\n\nI don't think it matters anyway, because the bottom fluctuates between 3 and 5 while the top increases indefinitely, i.e. approaches "infinity" if you like.  So there's no limit.
700521
Any welding supply house should have it.  It's used in MIG (metal-inert gas) and TIG (tungsten-inert gas) welding, to shield the molten weld to prevent oxidation by the air.
315423
all welding uses a heat source to melt the parent metal, parent metal is the metal you are trying to weld.\nWhen the metal melts, it can absorb gas from the air. This is not good, oxygen causes corrosion and hydrogen creates bubbles is the metal which weakens it. So when you weld you need to doo something to keep these gases out.\nOxy-acetalence or oxy-l.p.g. welding uses a gas flame to melt the paretn metal. The ratio of oxygen to acetalene or l.p.g. is critical for burning cleanly and not get oxygen in to the weld. Additional metal is applied by a filler wire, dipped in manually by the person welding.\n\nM.I.G. and T.I.G. use an inert gas (the I.G. in their name) to keep the other gases out.\n\nStick welders (manual metal arc) uses the flux around the welding rod to create a suitable atmosphere around the weld pool.\n\nmig, tig and arc use an electric current to melt the parent metal\n\nwith mig, the machine feeds extra metal in to the weld the whole time.\n\nwith arc the welding rod supplies extra metal\n\nwith tig the operator adds filler wire manually as required.\n\nTig does the nicest welds but it the most expensive as it is slow.
240485
It could potentially be both depending how the substance is heated [and let is not forget about radiation].\n\nIf the heating element is at the bottom, some of the heat is obviously transfered to the gas/liquid through conduction, but afterward, convection currents form to transfer heat more effectively.\nIf the heating element is at the top on the other hand, convection currents wont form quite as much and you must rely much more heavily on conduction to transfer the heat.  A similar situation occurs if you have the heating element on the side, in the middle of the gas/liquid.\n\nhttp://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatra.html
7409
Hi my freund.\nTIG is one of the method of fusion arc welding which its exat name is GTAW(Gas Tungestan Arc Welding)and contain a tungestune electrode and some sheilding gas such as Argon and Helium .\nI dont know how much information do you want.If you need more you cam mail to me by this address:\nmostafahedayati@yahoo.com to answer more accurately.\nGood luck
454802
it's basically from the movement of electron transfer from one of the metal to the other. to know the flow of electrons from which metal to which, u need to know their standard reduction potentials
983655
click and drag it back to the bottom
367516
here are the anwsers in order from top to bottom \n-T\n-T\n-F\n-F \nhope this helps
313165
In simplest terms, the valves move like this:\n\n1.  Piston down - intake open, exhaust closed (injecting fuel)\n2.  Piston up - intake closed, exhaust closed (compressing fuel)\n3.  Piston down - intake closed, exhaust closed (igniting fuel)\n4.  Piston up - intake clsoed, exhaust open (expelling gas)\n\n(The exhaust valve opens earlier than in step 4, but it's easier to write it this way.)\n\nSo for the power stage of the 4-stroke cycle (the ignition of the fuel), the valves are closed.  Answer D.
300753
Aircraft structure requires a fail-safe approach to design which is difficult to obtain using fusion welding however welding is used in certain areas such as ducting.\nBest I can do with one sentence.
896366
tack welding is a small application of weld metal.  it can be used in two ways.  One is in places where the loads are small so not much weld is required.  But it is usually utilized to hold two pieces relative to each other.  it still allows moving the pieces by striking with a hammer for minor adjustments.  Once the pieces are in place to the satisfaction of the welder and quality control inspector, the real weld is applied.  Many time once the permanent weld is started, the tack weld is ground off.