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Up Topic Welding Industry / Technical Discussions / TIG help....beginner.....
- - By turbo38t (*) Date 01-20-2006 01:12
.....now my major problem. The other night I was TIGGING for the first
time.....maybe this was beginner's luck......but everything worked out perfect for the first two
nights.....now here is the problem I am having. For some odd reason the oxide is either not coming
of fully or it is reforming quickly. I am in the same location, on the same table with the same
batch of aluminum, same type and same batch of rods. I am using a new stainless brush since the
first night just for the aluminum. The only things that I have changed are the gas pressure and I
used the machine for stick the other night but switched everything back. I need help. It's so
frustrating lol....anyways, I am getting good looking welds as far as burn in and uniformity but
basically I am dabbing the filler through the floating oxide.....the black stuff.....the welds
aren't really poris but the two pieces of metal are not flowing together right away like when they
are clean, it's taking time for the oxide to boil or float to the top before the pieces melt
together, and then it's a litttle more difficult to keep the puddle going but it is doable. Am I
not cleaning something right? What should I set my gas at? This is like 3/32" aluminum and the
next size smaller...only welding the same sizes together though. I even tried cleaning the filler
rods and metal with NAPA non chlorinated brake wash.....is my brush prematurely
contaminated....although I did try another new one....arghhh.....also, I need some sugestions on
how far the balled tungsten should stick out of the cup. I am using the green pure
tungstens.....thanks for all help and tips, this really is a great group. Dave

Parent - - By Lawrence (*****) Date 01-20-2006 01:42
Dave

Here are a few things to check.

Polarity:
Is your welding machine set for AC? If you were stick welding DCEP than you may need to switch to alternating current.

Balence Control:
If your power supply is a square wave than this setting should be no higher than about 6 on a 1-10 dial for the work your doing.

Clean Electrode:
If your electrode is not perfectly clean you will have trouble, especially with aluminum. Aluminum tends to run up the tungsten if you dip it onto the work or touch it with your filler rod. If you don't get all the contamination off it will just transfer back across the arc as smut on the top of your weld and make for poor welds.

Stickout:
Make your stickout no longer than the inside diameter of your cup (gas nozzel)

Don't know about the brake cleaner but:
If it leaves any residue it's no good for aluminum. If its a halogenated solvent like tri-chlor than make sure your work area is fully vented before you strike an arc as the vapors will create deadly phosgene gas when the UV from the arc intersects with the solvent fumes. Whatever, keep the spray can clear of the work bench.

So check those things and than if trouble persists. Let us know the following:

What make and model of welder your using.

What polarity your set on.

What is your balence control setting?
Parent - - By turbo38t (*) Date 01-20-2006 02:03
Hmmm, doesn't appear to leave a residue, but maybe the brake clean is, but was having the problem before using it. My machine is a Miller Syncrowave 180sd 2002 model. Diamond back 17 air cooled torch. On this machine to switch from dc to ac....ac is in the middle, you have to switch the lever to the left for dcen and to the right for dcep......it "clicks" into the dc modes but feels like you have to find the position on ur own to set the ac.....I mean, it works though, and the HF seems to work properly.....it creates a big multi stringer arc to start the arc then settles down to a fine arc about 2 seconds later.....no other adjustments besides a TIG/stick switch(it's in tig mode), the polarity setting, and the voltage setting....using my foot control for power....and i know what the "good" puddle and weld look like as it was working for me, but no I can see the oxide floating on the puddle and can actually see what appears to be the hf part of the arc glowing like a purple static electricity type arc once in a while off the floating oxide. Dave
Parent - By aevald (*****) Date 01-20-2006 05:51
Hello Dave, everyone that has responded to your questions has given you great suggestions on things to look for and to try. You mentioned in one of your sentences something about seeing a purple color in the arc. My experiences with colors in the arc when welding aluminum typically indicate that the purple color indicates the presence of magnesium. Is there any possibility that any of the rods that you are using could possibly have been mixed in with some magnesium filler rods? Most of the time when the filler is of a 5356 grade the arc colors will be somewhat greenish and if the filler is a 4043 grade the arc color may be more of a pink hue. Another thing about trying to weld aluminum base material with magnesium rod, the weld will not fuse readily and if a bead is formed it may fall out of the joint in one long piece when any sort of force is applied to it. You can check the filler rod you are using and any type of base material that you are welding on for the presence of magnesium by getting ahold of a solution of silver nitrate and putting a drop of it on the material, if the drop turns black there is magnesium present, if the drop stays clear it is aluminum. A question for you, when you first try to form the puddle before you add filler rod does the puddle cloud immediately and does the area immediately surrounding the puddle show no indication of the HF cleaning action of the oxides? If so that is a pretty good indicator of possible shielding gas problems or possibly DC reverse polarity current being present instead of AC. Initially my suggestion for you would be to very carefully check all of your initial machine set-up hookups and connections, proper polarity, tight gas connections at all fittings and no gas leaks, proper assembly of torch components,(tungsten collet inserted in the proper direction, all parts included in the assembly of the torch head,spacers,o-rings,any other gaskets), I had the experience of putting the collet in backwards on one particular style of torch and even though you could hear the flow of gas and feel it, it disrupted the flow in such a way that it would not shield properly, once it was installed in the correct direction everything worked perfectly. Along this same vein, make sure that your collet parts are for the specific diameter of tungsten that you are using, some torches have different components for each different diameter of tungsten that can be used. Make sure that you are using the proper flow rate for the particular size of cup that you are using on your torch, smaller cups require reduced flow rates when compared to larger cups. As one of the other posters stated, an incorrect flow rate can create turbulence that will actually draw the surrounding atmosphere into the weld zone when the flow is too high and obviously if the flow is too low there will be insufficient gas to shield the weld zone properly. One other question, when you have tried to start the weld and run a bead and then stopped welding or trying to weld is the tungsten maintaining the the ball that you started with and is the tungsten still shiny without any indication of oxidation or blackening? If the tungsten is staying shiny that would be an indication that your gas shield is performing properly, if not, it would indicate that there is a likely gas issue. Here again the answers to those questions would point you in the direction of equipment problem or material or filler issues. One more thing, when you are welding are you keeping an eye on where all of your leads, gas lines and related components are? The reason that I bring this up has to do with having kinks in gas lines because they snag on things, having things laying on top of the gas supply line causing a lack of gas, having hot parts, sparks or other things put holes in the gas supply line, even setting the leg of your welding stool on the line cutting the supply of gas off that way. Sorry for the long winded response, I'll be curious to learn what you find to be the problem. Regards, aevald
Parent - - By Ken Dougherty (**) Date 01-20-2006 03:52
Some more thoughts-- (I have a Syncrowave 180 also.)
1. Could your gas be contaminated? 2. Shielding gas pressure needs can vary but if too high, turbulance may prevent good shielding. I seem to have good luck w/approx 15psi. Don't tilt your torch too far from vertical or you may lose your shielding. 3) wire brush in only one direction to prevent working oxide into metal. Acetone, after brushing, seems to work as a cleaning agent for me. 4) Alloy of metal/filler may cause black smut. Magnesium as an alloy element (e.g. 5356) prone to black smut if shielding is poor.
Good luck. Ken
Parent - By turbo38t (*) Date 01-20-2006 11:16
Hmmmm, the funny thing is I didn't change anything from the last time besides hooking the stick up and then rehoking the tig setup up. I was at around 25 psi with the small stock db17 torch cup, maybe that is too much, I did tinker with the gas when i started having probs. I did not use any cleaning agent the first night and it seemed like I could not go wrong, I even tried recleaning that same piece and could not get a good bead. I used new filler rods from the same exact pack, also tried fifferent sizes of the same type. I resharpened severak different tungstens and reballed them. Seems like the hf is really cleaning pretty good but there is alot of oxide on the material. I am wondering....the first night I welded was in my garage.......it went from 55 degrees during the day to 25 at night.....the garage is heated though, but not very well insulated......now the second night it was just plain cold, like 25 -30 degrees.....now the last two nights it was warmer outside the garage than in.....like say 40-45 outside and like 25-30 inside .....I start the wood stove and that's it....figured I'd throw that in, I wasn't sure how fast exactly that aluminum oxides......I already checked the hoses, no kinks, I checked the quick connect. ......rehooked it up.....the gas is in a new bottle(100% argon), I let it settle for a few hours the first night....that's what the welding shop suggested.I'll check the hose fitting on the back of the welder again. Sounds like an air problem to me....as I am really taking the extra step to clean the material.....only other possibiility is that maybe my wire brush got contaminiated. Dave
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