Considering a TIG purchase - syncrowave 200?

[Steve St.Laurent]

Here's the other jig. This is welded on DCEN. One thing that I find happening on mild steel on DCEN is when I'm finishing the weld I get a little "pimple" because the weld pool is being drawn towards the tungsten as it cools - how do I avoid that?



Here's the jig showing some of the welds:



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and what it's used for (cutting the legs shorts on the manufactured table legs that I purchase with a band saw):



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as always - any suggestions appreciated!!

 

[Steve St.Laurent]

Ok, next question. I'm adding a shelf to my welding cart for the tig welder along with a couple hooks to hang the cables on. It's made out of mild steel 3/4" square tubing 1/16" wall. I'm using DCEN with the pulser turned on at 70 amps peak pulse, 50 amps base pulse - 50/50 at 100hz . I was having trouble burning through without the pulser and with it I have a lot more control and am not burning through. The thing is the electrode is getting used up real quick. It balls up and I have to change out to a new electrode because the arc is wandering. I'm changing out electrodes at about the same point where I've used up a 36" 3/32" filler rod. Is this normal for DCEN or am I doing something wrong? I've been doing mostly AC welding with it and that doesn't happen at all on AC - the only reason I've changed my electrode on AC was because I contaminated it or was changing material.

 

[sstefanini]

The pimple @ the end is called a crater. If your machine has a crater fill feature you can use this to "downslope" your amperage to avoid leaving it. Or just let off the footpedal a little slower . Craters are caused by ending the weld at full welding amperages. As far as the tungsten issue are you using 2% thoriated on straight polarity?

 

[Steve St.Laurent]

This seems different than a crater unless that's what happens on DC on steel. I had crater problems on aluminum and figured that out. This looks lke a small hershey's kiss - it sticks up from the weld. I could what the metal draw towards the tungsten as I was sloping out. I'm using 1. 5% lanthanated tungstens on straight polarity. Lanthanated was suggested for my inverter based machine.

 

[GHarman]

Steve, Looks like you have been busy! I would use 2% Ceriated or 2% Thoriated. If you are working in an industrial shop Thoriated tungsten is fine. In a home shop, if you have children, or just simply dragging it into the house, Ceriated tungsten is less health risk. Thoria is radioactive. A Beta emitter. It washes off on the outside and cant penetrate your skin. If you ingest it or inhale it that is a different matter. Wear a dust mask when grinding! Slope out your amperage slowly at the end of your weld and move the tungsten around as the puddle gets smaller, on carbon steel. What filler rod are you using for carbon steel? I like 70S-2 and 70S-6. The 70 is the tensil strength (70,000 #/ sq. in. ) and the number suffix refers to the deoxidizers in the alloy. On your aluminum angle weld, start adding filler at the beginning of your weld and cut back on your heat to get rid of the sucked back corner. You are making to big of a weld on the carbon steel. A proper fillet weld on carbon steel should have a flat to convex face. A concave face indicates to much heat and/ or not enough filler metal for the weld size. A stress riser situation. Make sure you are in DCEN, if the tungsten is forming a ball you may be in DCEP. Looking Good! Will write more tomorrow. GregH.

 

[sstefanini]

I thought that was a crater when I glanced at the first pic but its the opposite. Carbon TIG makes a pretty trashy weld and you can carry silicon in the puddle... But unless it's hollow under the tit when you bump it with a grinder I would'nt worry about it. I've never used lanthanated tungsten as I think its more a european thing due to radioactive dust, but if I had to guess I'd put my finger on this as a possible cause of poor tungsten performance as . It also could be one incorrectly flipped switch on the power supply as those inverters have sooo many settings on them (personal experience).

 

[GHarman]

Steve, You are trying to weld the carbon steel tube as if it were aluminum. To much heat, to big of a filler rod. Try 40-60 amps and 1/16" filler rod, no pulse. You may have to adjust some on the amps, use your foot pedal. Carbon steel welds better if you remove the mill scale. More time in prep work. Better looking welds. GregH

 

[Steve St.Laurent]

I'm using ER70S-2 on the carbon steel. I was using 1/16" filler rod and I was using the pulse because it worked better for me when doing butt welds on the square tubing. I tried it without pulse at first and had much better results with the pulse. I was definately in DCEN - on my machine I'd have to unplug the cables and move them to change to DCEP. I did remove the mill scale btw. How about arc length? If I had the tungsten too close to the work could that cause it to melt? I also realized that I had the hot start turned on (left over from the aluminum work) and I think I had that set at +50a. One guy suggested that I may have been blowing material off the carbon steel and contaminating the tungsten right out of the gate. I did remove the mill scale btw.



The pictures at the top of the page (2nd jig) was 1/4" cs and I was still using the 1/16" filler rod - too small for that material I'm guessing which is why the weld was slightly concave. I couldn't tell you why now because I have 3/32" and 1/8" 70S-2 as well - brain fart I guess. Sure am learning a lot!



I'm going to have to get my tank filled soon - I've almost emptied the 122 cu ft tank that I upgraded to (from a 20 cu ft tank I used with my MIG which I emptied the first day)!

 

[GHarman]

Steve, You want to keep a tungsten to work distance of no more than the diameter of your tungsten as a rule of thumb. Try walking your cup on the carbon steel welds. You will maintain a consistant Tung. / Work distance if you master the technique. Mill scale is the dark coating on hot rolled steel, once you remove this to bare metal it no longer is a problem. The scale you get on your weld (carbon steel) is a result of the interaction between the impurities in the base betal and the deoxiders (getters) in the filler material. Usually in the form of a brown scale deposited here and there. A severe amount of this scale is indicative of to much heat. There should be no undercutting at the toe of the weld. I highly recommend a 300 Cu. Ft. tank of argon. Price/cu ft value. As long as you can handle the tank! I have 2 of them because I am so far away from my supplier. They last a while. unless I get a job that requires a purge. ( I will rent a helium tank if I do large section Aluminum). With a 3/32 filler rod and walking the cup, using the "laywire technique" you should be able to make a fillet weld with 3/16" legs that looks like a catepiller crawled in the corner and blended into the metal =) . (A weld that has no eccentricities The toe of both legs of a fillet weld are parallel. The weld is perfectly proportioned and the chill rings are duplicates of each other, with no undercut and a flat to slightly concave face. ). This is not as difficult as it may sound. With the small tube you are stuck free handing it unless you set up a rest for your arm or hand and grip the torch like a pencil. Have fun, GregH

 

[Steve St.Laurent]

Uhhh, I need a couple of those things explained if you can - walk the cup and laywire technique.

 

[GHarman]

Walking the cup- Setting the trailing edge of the cup on the joint to be welded. Using a rotating oscillating motion with your wrist, rock and roll the cup, advancing your puddle as you see the puddle wet to the edge of the specified requirement ( usually per Weld Procedure specification ).

Lay wire technique- used in open root, V-groove or fillet applications. Instead of dipping the rod in and out of the puddle, feeding it through your fingers- Lay the filler in the joint at the very center if the joint, with a slight amount of pressure maintained on the rod, walk the tungsten along the filler rod oscillating from side to side no more than the width of the filler rod fusing the filler and base metal as you advance. This is the quick and dirty explaination. There are a lot of nuances that are left to look for and learn. Wish I could show you. Maybe there is someone locally that could give you a hands-on? GregH.

 

[Steve St.Laurent]

That makes sense - thanks. Actually I had already come up with the lay wire technique on my own. Had played with that some where I had a gap in an open groove corner. Was going to ask if there was anything wrong with doing that but hadn't gotten around to it. Slowly but surely you guys will make a welder out of me!

 

[GHarman]

Sounds like you are well on your way! There is always something new to be learned even when you are set in your ways. My mottos are 1. Manipulating Molten Metal for the MASTER! 2. I will stop learning only when HE has appointed someone to shovel dirt in my face! =) GregH.

 

[HoleshotHolset]

You want to keep a tungsten to work distance of no more than the diameter of your tungsten as a rule of thumb.

Do you have any hints to improve upon this? My arc length can sometimes be measured in inches (an exaggeration... ) - I'm too chicken to get the tungsten right in there.



Sometimes it seems like I need to relax and take it easy before jumping right in... otherwise my hands shake and the welds show it.



Matt

 

[GHarman]

Hey Bud, My hands shake too! Especially after a good cup of coffee=)! (natural oscillation =). ) Rest your hand on something, or learn to "walk the cup". Do dry runs with no light-up. Practice pointing the tungsten at the center of the weld joint with the tungsten no more than a diameter away, The trailing edge of the cup resting on the weld joint. Hold the torch with your fingertips and with a gentle rocking motion from the wrist jog the torch back and forth with a rolling advance. This will work well with carbon steel and stainless steel. Aluminum requires NO torch contact. Here you can set up a fixture to rest your hand and slide it along. There is no such thing as cheating, only good welds and bad welds. GregH.

 

[HoleshotHolset]

There is no such thing as cheating, only good welds and bad welds.

That's a great piece of advice right there!



Matt

 

[nickleinonen]

That's a great piece of advice right there!



Matt

yep... and all my good welds are never visiable, and my bad ones are the ones you see

 

[GHarman]

Unfortunately, there are a lot of different levels of welding. I am glad that you have your hand in the trade. Keep practicing if you enjoy welding. You will improve. Under code requirements, all welds are subject to the approval of a Certified Welding Inspector, at a minimum. Wait until you are required to have all phases from setup ,tacking, root pass, hot passes and coverpass, each visually inspected and signed off before it goes to X-RAY. Talk about pressure! =) There are folks who do this daily, and make good wages. GregH.

 

[Steve St.Laurent]

I thought some of you guys that helped me get started might be interested in seeing the progress. This is a water tight aluminum box made out of 1/8" 6061 that will house a battery, a couple of switches, and a fuse panel to make my cr250 street legal. Have to do some machinine on the front panel this weekend for the face plate seal.



Having a blast with this little box.

 

[GHarman]

OUTSTANDING Steve! A little hot at the ends. Slope out and add more rod to cool the puddle. You can also use chill blocks so your corners wont have that wavy look. Use chunks of COPPER BUSS BAR. Polish them up. Clamp 'em tight. They work great! Happy Thanksgiving. GregH