Must tig better...

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First post, been lurking. I have been using a small microtron inverter welder, but today I picked up an old square wave linde/ltec/hsab.  That being said the welds im going to discuss are on the newish microtron.  I have experienced similar results on the old machine, but its much easier to get a good pool with the old machine, and this old machine will be the one I use going forward(the newer tig is not mine and I would hate to break it.. very pricey machine, used in the shop for mold repair)Amp: 90-120Frequency: 60Material 4130 090 wall, notched/fismouthed clean.Wire er70s2So I have been noticing that it looks almost crystallized on the top.  I have tried different frequencies, different power, and different wire, but I always experience the same results.  Basically a 'dull' finish.  I am a beginer and am willing to except my complete ignorance.  I have read any book I can find at the local book store, but the knowledge I have gained is obviously no match for proper experience.  It is my goal to make as few mistakes as possible along the way.  Here she is  http://www.flickr.com/photos/joshgor...04527/sizes/l/
Reply:Originally Posted by joshuagoreFirst post, been lurking. I have been using a small microtron inverter welder, but today I picked up an old square wave linde/ltec/hsab.  That being said the welds im going to discuss are on the newish microtron.  I have experienced similar results on the old machine, but its much easier to get a good pool with the old machine, and this old machine will be the one I use going forward(the newer tig is not mine and I would hate to break it.. very pricey machine, used in the shop for mold repair)Amp: 90-120Frequency: 60Material 4130 090 wall, notched/fismouthed clean.Wire er70s2So I have been noticing that it looks almost crystallized on the top.  I have tried different frequencies, different power, and different wire, but I always experience the same results.  Basically a 'dull' finish.  I am a beginer and am willing to except my complete ignorance.  I have read any book I can find at the local book store, but the knowledge I have gained is obviously no match for proper experience.  It is my goal to make as few mistakes as possible along the way.  Here she is  http://www.flickr.com/photos/joshgor...04527/sizes/l/
Reply:You really want straight DC for steel.        Sincerely,             William McCormick
Reply:dcen."SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:what shielding gas are you running? shielding gas probably has the biggest impact on bead appearance.also a good test, is to start an arc, make a spot turn off the torch and don't move giving plenty of time to purge.  If the spot is still dull looking then it signifies a leak, bad gas or dirty material that won't produce a nice clean bead on it's own. that's the first diagnostic I do.
Reply:Ac creates an etched zone around the weld.  This is considered good for aluminum, but you want DC for steel.  Maybe that's the look you're describing.
Reply:I meant to say pulse.So I have started doing all my practice on the Linde/L-tec.  I figure if this is the machine I am going to use might as well be using it.  I purchased a new torch, and a bunch of extra supplies, and started with a fresh piece of metal, fresh tungsten, and everything cleaned with acetone after cleaning/grinding.I still get what I am calling crystallization.  I have ran anywhere from 10-40cuft a minute, but still the same results.  I am using a gas lens, and have wandered from 50amps to 120amps with the exact same finish.  The belt used to clean the metal was brand new.. meaning I installed seconds before cleaning the metal, and the wheel used to cut the tungsten was brand newHere is the latest including pictures.New Gun and tungsten depth.Clean gas lensWith FillerNo filler.
Reply:Originally Posted by joshuagoreSo I have been noticing that it looks almost crystallized on the top.  I have tried different frequencies, different power, and different wire, but I always experience the same results.  Basically a 'dull' finish.  I am a beginer and am willing to except my complete ignorance.  I have read any book I can find at the local book store, but the knowledge I have gained is obviously no match for proper experience.
Reply:Just saw your new pics. I'm going to stick with too slow of travel speed.
Reply:The crystallization appears immediately after the spot goes cold, i can almost watch it happen a ways back behind the torch.  I will try and go faster.Josh
Reply:I went as slow as I could without burning through and as fast as I could without burning through.  Similar results.  The fast weld just had more filler above the metal and the slow weld had more filler 'in' the metal.  Is it possible that its getting hot enough to get crap from the inside of the tube where its obviously not ground?p.s. I am running straight dc, for sure.
Reply:Originally Posted by joshuagore I will try and go faster.
Reply:If I wire wheel the welds they clean up and they are shiny...?Josh
Reply:I would not let the machine pulse. You are going to get some crystallization in steel welds. I have never seen a steel weld without some. I would manually pulse the pedal myself. The trick to keeping stuff (contaminants) from traveling up a weld with the puddle. Is to cool the puddle, when you are totally loving it. The puddle should be penetrated, filled in, melted in. And then you cool the puddle, and move perhaps 1/8' inch and do it all over again. I just keep the torch lit enough to see where I am going. And do it again. One tack at a time. It is a done deal every time that way. Over the years engineers, would setup the perfect weld, for TIG airline welding. And they would have the perfect machine pulses and it looked unbelievable. The only problem was it broke upon cooling. Or did not pass X-ray because it had this faint line, down the hole weld. The same contaminants were still in the other welds that passed. But the line was broken or dotted, Usually they were washed to the surface. Where they could be removed by surface preparation or finishing. Using the machine to pulse, can cause some nasty effects on metal. You are changing the direction of heat flow, back and forth, back and forth. But you are doing it with no purpose. You might be in the same spot and heat and cool the exact same area more then once. That is not good welding practice. You could dredge up contaminants twice and deposit them twice in the same place. Another thing that you should know is that, when you cool the puddle, the heat in the puddle instantly moves up with the torch just emitting light. So you will find that by turning the torch almost off, that you will still have heat in the part, when you go for the next puddle. It will just melt right away, take wire right away, and then cool right away. This is also good for making that arced hollow looking weld.           Sincerely,              William McCormick
Reply:STOP- STOP  I repeat STOP  welding the Roll cage on the Race car .To pass tech the Cage must be weled by a Pro welder, contact the SCCA /or local track tech dept. Yes Learn to weld BUT not on the cage. What tubing are you using ? thickness ? I'm a racer an understand the passion an I want you to be SAFE , I have lost friends in Pro built cars anwant you to be Safe .
Reply:Originally Posted by RentawrenchSTOP- STOP  I repeat STOP  welding the Roll cage on the Race car .To pass tech the Cage must be weled by a Pro welder, contact the SCCA /or local track tech dept. Yes Learn to weld BUT not on the cage. What tubing are you using ? thickness ? I'm a racer an understand the passion an I want you to be SAFE , I have lost friends in Pro built cars anwant you to be Safe .
Reply:If you haven't already then download the Miller TIG guide from http://www.millerwelds.com/resources/improving-your-skills/tig/ You've got a gas shielding quality issue (at least). One suspect would be the badly fitted gas lens...Shouldn't be able to see the collet body between the ceramic and the insulator (white ring) yet there is a clear copper coloured ring visible. There is an additional or specific gas lens insulator part # 54N01 available to fix that. The manky grey colour is surface oxidation (hence why a wire wheel cleans it up). A common cause of this is not keeping the end of the wire within the gas shield (pull it out and the hot end'll oxidise only for the oxides to be added to the pool next dip of wire) but as you autogenous (without filler) welds are oxidised too something else is going on. Arc length could be too long, too much gas flow can reduce gas shield quality but first job is to check everything for leaks. A spot weld test on stainless works well to check for gas problems- form a puddle shut off the arc and pause for a few secs for the post flow, spot weld should be totally colour free i.e. like a spot of freshly polished stainlessObviously doesn't matter much when messing around with offcuts but autogenous welds and 4130 DO NOT go together.
Reply:I think Hotrodder hit at least part of the problem.  There should be a little insulator adapter between your pink cup and the white insulator.  Costs $1 to $3 if I remember correctly.My name's not Jim....
Reply:I will order that part.  I also welded with a non lens tip with the same results.  I will check internally in the machine for leaks which may be dragging o2 in?Josh
Reply:2 possible issues; 1 would be the gas lens looks wrong. Be sure it's what you need.2.... that weld looks like you are using 90/10, 80/20 gas. Are you sure you are running straight argon??In a pinch, I have used the Stargas I normally use on mig. It gave very similar results. Good news was, after painting, it looked perfect.Mind you, this was a bumper, not a roll cage. Check the gas. Try a different bottle and the right tip.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by Rojodiablo2 possible issues; 1 would be the gas lens looks wrong. Be sure it's what you need.2.... that weld looks like you are using 90/10, 80/20 gas. Are you sure you are running straight argon??In a pinch, I have used the Stargas I normally use on mig. It gave very similar results. Good news was, after painting, it looked perfect.Mind you, this was a bumper, not a roll cage. Check the gas. Try a different bottle and the right tip.
Reply:Originally Posted by RentawrenchSTOP- STOP  I repeat STOP  welding the Roll cage on the Race car .To pass tech the Cage must be weled by a Pro welder, contact the SCCA /or local track tech dept. Yes Learn to weld BUT not on the cage. What tubing are you using ? thickness ? I'm a racer an understand the passion an I want you to be SAFE , I have lost friends in Pro built cars anwant you to be Safe .
Reply:Originally Posted by joshuagoreI hear your warning, and sleep well knowing this is not some fly solo, lets see if I don't die scenario.  I have hands on help and advice from people who have experience fabricating, and racing beyond the scca.  Although my post may imply a naive ignorance, I did post at first sign of trouble.  Josh