When to replace TIG consumables

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Greetings and all that,I feel a bit frustrated, maybe this is a bit of curiosity and maybe this is a bit of venting.  I guess it's pretty obvious how electrodes go, as they get ground and such they vanish.  But what of the collets, collet bodies, back caps and nozzles?  Plenty of my stuff is dirty, the nozzles might get broken, but what would cause it to need to be replaced?  I can hardly imagine a collet or collet body ever needing replaced, do you ever replace them?.  What about the back cap?  I see this little rubber band looking guy and I wonder if he wears out from the friction when the cap gets put on and off.Miller 330 a/bp water cooledI believe in gun control, I hold my gun with two hands.  If you want to know why, click here.Buy American or bye America.
Reply:The o-ring seal in the back cap is replaceable with any o-ring of the correct size.  Back caps are cheap enough to replace too.  If the back cap gets cracked or the o-ring stop sealing, you have a gas leak and may be drawing air into the gas flow too.  Same with the nozzle and insulator.  The collets and collet bodies seem to last forever.  Gas lens screens get messed up once in awhile.   None of these parts are expensive, so no big deal if you have to replace something.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Hello pinjas, for the most part a visual inspection of the general condition of all of these various parts will give you the answers as to whether it's time to replace/repair the various parts of the tig torch. Back caps, for instance, are good to go indefinitely unless the threads are damaged, the bodies have cracks, been otherwise broken, or the o-rings are cut/deteriorated. The collets, depending upon the type, can be crushed, bent, or otherwise damaged to the point where they will no longer hold the tungsten electrode correctly, damage can also possibly impede proper gas flow/coverage, thus requiring replacement. Any of the parts of the tig torch that have threads can be damaged to the point that they might need replacement or reconstitution of the threads, internal/external. The problem with thread repairs on these items generally is about having the correct dies/taps to make the repairs, they are not the readily available diameters and threads per inch type taps/dies that are readily available. A lot of these parts are copper and galling is pretty common when dirt is allowed to get into the threads or someone inadvertently cross-threads one of them. Abuse, general wear and tear, and accidental damage can cause replacement/repairs to be required of any of the parts of the system. If you have a flex-head type of torch, repeated bending/straightening of the neck on one of these can cause the internal parts to work harden and crack or break, thus requiring replacement. They can not be repaired economically. Maybe this rundown might help to answer some of your questions. Best regards, Allanaevald
Reply:One thing I have noticed is when I screw in the back cap it doesn't seem to screw in all the way.  I suspect it may have something to do with the size of the collet, I almost think I am using the wrong collets as I seem to be having some sort of strange and consistent problem no matter how I setup the torch.  It's sort of like a spiking in amps, as though I slam my foot down on the pedal for just one or two (cycles?) moments.  Just a few of the little sparks that are shooting are extra strong and bright, I don't know how else to define it.  At times it goes from strong and stable to not so stable and then I burn a hole through the aluminum.I am learning, and I am learning on aluminum, and the aluminum is thick, hah!I haven't been welding anything, just laying fake beads, no filler, but after I run a few feet and let off to inspect I often cannot start a new arc for a minute or two.  I adjusted the high frequency contacts and intensity, the HF contacts needed to be at something like .010 apart, the HF intensity is set to it's maximum (10).  Can anyone imagine that be the cause of any of these sorts of problems?  I can imagine something that generates the high frequency to be taxed when set at max, but I have no idea otherwise.Miller 330 a/bp water cooledI believe in gun control, I hold my gun with two hands.  If you want to know why, click here.Buy American or bye America.
Reply:Hello again pinjas, one way that you can check the relationship of the torch parts goes something like this: take the back cap off, remove the collet and tungsten, remove the ceramic cup and check to see that the diffuser is completely screwed onto the front of the torch. Now screw the back-cap back into the torch head, it should completely bottom into the rear of the head. At this point remove the back-cap and insert the collet, reinstall the back-cap and screw it in fully or as far as it will go before it gets tight, take note of the gap, if any, between the rear of the head and the mating portion of the back-cap. It may tighten in completely the same as when it didn't have a collet installed or it may leave a slight gap. Finally install the tungsten into the head with the collet and re-install the back-cap and see how much gap you have now between the rear of the head and the mating surface of the back-cap. You should have a greater gap at this point than you had in either of the two other scenarios that I described prior to this final one. This difference in gap will be very slight, likely a 1/16" or less. Whenever this gap is no longer present you have probably distorted or otherwise damaged the collet and it will no longer do the job of properly clamping and holding the tungsten as it was designed.      Your starting problems could be tied to other issues than the torch or even the high-frequency generation circuit itself. If you have poor connections in the various terminals on the torch side of the unit they will impede the proper action of the high-frequency and possibly cause it to bleed off or be greatly reduced. I believe there is also an issue with the type of tig torch supply cable that you use with the high-frequency, some are designed to be used with it and others are not. It has to do with the construction of the cable, it's shielding/containment capabilities, and other such items. A bit more for you to consider. Best regards, Allanaevald
Reply:If you have a water cooled torch (as stated on the bottom of your post), you need to be sure you always have water flowing while the unit is running. Trying to weld without it will overheat the cable and melt the plastic tube.Eventually, after lots of flexing, the cable may get work hardened and break; this can lead to poor starting and an erratic arc too, because as the torch is moved, the cable contact surfaces  inside the hose can make and break. I found a discarded cable like that once; can't remember if the torch was still attached too.
Reply:Hmm, sounds like a lot to chew on.  I am always certain to have the water cooler pump running for a bit before I even turn the machine on.  I recently redid the ground clamp by unscrewing the wire from the clamp itself and then cutting off a few inches of wire and exposing new wire to it.  I also removed, and cleaned the connection to the machine itself.  I am considering doing the same to the torch connection, it looks a little scary to me.  Maybe I will replace the cables, they look expensive.  I never really imagined cables being designed for high frequency.  I was extremely worried about high frequency feeding back into the power lines and getting radiated to other devices, I often have a classical FM radio station going when in the garage (99.5) and I haven't heard a bit of interference.  I have the machine grounded to a grounding rod and I thought that maybe the grounding rod was too efficient in removing HF, but that sounds unlikely.I was doing a bit of reading recently and I came across a thread on a miller forum that suggested that soldering the cables (source http://www.millerwelds.com/resources...ad.php?t=14836) into the connection was a good idea, and to me, it sounds pretty wise.  No corrosion, no gradual loosening, 100% connected.  I could be wrong, as these fellows, but it sounds good.I have inspected the water cables pretty thoroughly, they look pretty clean and new, I doubt they are generating any sort of problem.Miller 330 a/bp water cooledI believe in gun control, I hold my gun with two hands.  If you want to know why, click here.Buy American or bye America.
Reply:Hello pinjas, after reading back over some of what you and others have included on this thread I noticed that I had mistakenly thought that you were using an air-cooled torch for some reason. There are some of the air-cooled units that aren't really designed to be used with hi-frequency type machines as the hi-frequency can bleed off. Sorry about that. Best regards, Allanaevald