[David_M]

Hello,

I am new to welding and just picked up the Lincoln Power TIG 200 and was experimenting.

Now that I have seem to have mastered what not to do, it might be useful to figure out what to do. Through this process my comfort with holding the torch, feeding metal, has improved. I think it is now a matter or settings and preparation.

All the welds in the picture (steel and stainless) The welds below were all done with 3/32 gray tip color tungsten.

The steel is 1/8 inch. I sanded/polished off the mill scale. I don’t recall if I wiped it with acetone. I ran this at about 125 amps and 15-20 CFH of Argon. I used ER70S-2 1/16 filler rod. (Is there an good reference for what the suffixes mean – in this case S-2? I Know ER is Electrode and Rod and that the 70 is the tensile strength.)

Mechanically I suspect the steel well is OK although one side is better than the other. What I noticed on all my welds, stainless and steel was that the welds do not come out clean like they do when I see them made on some of the YouTube videos of Jodi and others

steel 1.jpg (26.6 KiB) Viewed 624 times

steel 2.jpg (30.32 KiB) Viewed 624 times

steel 3.jpg (31.32 KiB) Viewed 624 times

The stainless weld is on material from an old prep table so I assume it is the type of stainless usually found in the food service industry. It is .047 inches think. I used about 75 amps, 15-20 CFH or Argon. The rod was ER308L 1/16. I did not do a very good job prepping the surface.

I cleaned the piece with a roloc scotchbrite after I was done. IT was pretty dark and scaley after I finished welding it.

I am assuming that the weld through on the back is from too much heat.

I would appreciate any suggestions. I have many more pieces of the stainless so I can practice, compare and repeat

stainless 1.jpg (18.77 KiB) Viewed 624 times

stainless 2.jpg (17.5 KiB) Viewed 624 times

stainless 3.jpg (23 KiB) Viewed 624 times

stainless 4.jpg (20.99 KiB) Viewed 624 times

Back side burn through

stainless 5.jpg (19.74 KiB) Viewed 624 times

[Lightning]

On your "T" joints, you need to focus most of your heat (like 2/3 of it) on the piece that would form the top of the letter "T".

The toes of the weld should "wet out" on both pieces, but the fact that the toes of the weld are not wetted out on the piece that forms the top of the letter "T" tells me that you were too cold there.

Think about thermal mass and where the heat is going...on the piece that forms the top of the letter "T" you are trying to heat up the middle of the plate, but on the other piece you are only trying to heat up the edge of the metal. That's why you need to put more heat into the top part of the "T" – because the heat has twice as many ways to escape as it does when you're heating the edge of the metal.

I'm sure others will chime in on the other welds.

[exnailpounder]

You're welding too cold. Are you using a pedal? You should be using more amps than the 1 amp per thousandth rule with a pedal. You are also trying to add too much filler. Tig welds are generally flatter than any other process. Inside corner welds are flat or slightly concave in the belly. Shoving in too much filler also cools your puddle and creates all kinds of problems. You are not melting both pieces of parent metal when you are doing your filets. You can see how there is more weld on the upright piece than the flat. Keep that arc short and right in the middle of the joint and make sure that your puddle melts out to a point before you dip. Don't dip in the keyhole or you are just bridging the weld.
You are absolutley cooking your stainless. More amps and you have to really move out on stainless as it doesn't conduct heat very well and the heat builds up and cooks your metal. You should always have color in a SS weld.
I would suggest staying with mild steel until you get your technique down before moving on to stainless. You need to be aware of each different metals characteristics before you weld on it. Mild is somewhat forgiving, others metals not so much...stainless being one of them.

[David_M]

Thanks for the suggestions so far.

I definitely was not holding the torch appropriately throughout much of these welds. I was off on both angle and distance.

One question basic question. I exnailpounder said not to dip in the keyhole. So do you dip in front of the key hole or behind?

Thanks,

[exnailpounder]

You want to have a completely formed puddle when you dip. If you are getting that keyhole, then both pieces of metal haven't melted equally. You want to make sure you melt in all the way into the corner, otherwise you are bridging and not getting good penetration.
Torch angle and arc length are very important also. If you arc length is too long, you increase voltage and induce more heat into the parent metal. Wrong torch angle and you can't control you puddle and have other problems like blowing holes. Jody has an excellent video out about the 3 most common mistakes that new guys make. Highly recommend it.

[motox]

maybe spend more time on flat beads, pad some beads till you
get more of an idea of torch angle, arc length and travel
speed.
craig

[Lightning]

It sounds "wrong" at first, but if you increase your amperage (press down more on the pedal and/or increase your panel setting) and then move faster, you will not put as much heat into the pieces you're welding and won't distort/cook/scale them as much. Try it.

[MosquitoMoto]

It sounds "wrong" at first, but if you increase your amperage (press down more on the pedal and/or increase your panel setting) and then move faster, you will not put as much heat into the pieces you're welding and won't distort/cook/scale them as much. Try it.

Couldn't agree more. I spent a week or so when I first started out using low amps, slowly cooking up a puddle and then moving ahead. By the time I finished my run the whole piece would be glowing red! By comparison, starting out plenty hot and motoring away fast is far preferable and the workpiece definitely stays cooler overall.



Kym