TIG 16 ga stainless fillets & butts (flat)

By Lawrence (*****)

Date 12-03-2007 11:16

1/16 tungsten and filler are fine.

A larger nozzel/cup and a gas lens might help with color.

Also a very small (5-10 degree) push travel angle, as close to perpendicular as possible will keep gas shielding over the weld longer.

A quicker travel speed will reduce heat input (which is the root cause of the oxides). This comes with practice.

Perfectly clean tungsten... If you dip.... stop and clean it.

By 19Slade52 (*)

Date 12-03-2007 11:55

Thanks, Lawrence! I
'm headed out to practice your technique this morning & I'll be sure to report my results to you asap!!!
Again, MANY thanks!!

By aevald

Date 12-03-2007 15:54

Hello 19Slade52, I might only add one additional thought to Lawrence's great suggestions, if you can clamp a backing piece behind the area you are welding on, it might also help with reducing the amount of discoloration you are seeing. A 1/2" piece of aluminum in close contact with the back-side of your weld area will help with preventing oxidation and also allow for not-so-perfect travel speeds and slightly excessive amperage. Once you have gotten to practice this process more you will figure out many of the little things that can make welding with the GTAW process so much fun. Best regards, aevald

By Lawrence (*****)

Date 12-03-2007 16:10

Good thought Allan

I almost always use a heat sink when I can get one clamped on.

By 19Slade52 (*)

Date 12-03-2007 22:03

Thanks for the input aevald! I was using a 16 ga backing for heat sink, but I like your idea of a 1/2" piece much better. I'll try that tomorrow. Thanks again!

By 19Slade52 (*)

Date 12-03-2007 22:00 Edited 12-03-2007 22:05

Although I achieved quite a lot of improvement, I'm not quite yet satisfied, Lawrence. I have a long row to hoe.
But thanks again for your contribution. It really did help. At least there is some shine, and not dull gray oxidation.

I have been out of the trade for over ten years and am just returning to it.
I used to sell welding equipment & consequently met some excellent welders, using some mighty fine equipment.
Used to see (and sometimes play with) the Miller Synchrowave 350 with pulse kit, which was GREAT for stainless.
Dial in the pulse intensity & frequency, and lay her in there, you know? SWEET!
Even a SALESMAN could produce some nice welds with one of those babies!
But, alas, now all I have to practice with is an old Miller 33O A/B P (you can no longer read the heat ranges on the panel!)
Am I expecting too much from this old Miller 330 A/BP war horse?

I've also had a lot of difficulty seeing the stainless puddle using a # 9 or a #10 gold lens. Could it be that my 55 year old eyes need a #8? I'm concerned I'll burn out what little night vision I have left, if that's possible. I see aluminum puddles quite clearly, but then they ARE brighter to begin with!

Any suggestions for either of these dilemas?

By aevald

Date 12-03-2007 22:24

Hello again 19Slade52, over time I have noticed a couple of other scenarios where the "color" as you say, isn't quite as bright and shiney as I felt it should be. Back to basics here just a bit: material grade and filler rod matched, a time or two I noticed differences in weld appearance when the filler rods and material weren't quite meant for one another. Next, materials absolutely clean and free of outside contaminants, use oil-free solvents or other cleaners designed for stainless steel and brush with a new dedicated stainless steel brush. Flow meter settings not too high or too low, too low not able to keep the atmosphere out of the weld puddle properly, too high creates turbulence and can actually draw atmosphere into the welding puddle. I generally start low on the flow rate and watch the results and then steadily increase until I am satisfied that I have proper coverage by the results that I see in the finished weld. Large cups work better for shielding unless there is some sort of restriction for access on a particular weld or in the case of pipe welding, the size of the cup suits the fit in the groove. Gas lenses will also aid when welding stainless steels and many other exotic classed alloys and are my preference when welding stainless steel. As far as your machine goes, you will be able to make terrific welds with that machine and I wouldn't worry about that. The eyes are another issue. Don't go lighter with your shade because you think you will be able to see things better. In some cases the glare that comes along with lower shades is what makes it harder to see. Start out with a good quality "glass" filter plate in possibly the 11 shade range, watch for the clarity and definition of the puddle edges, this is really the key in my opinion, go up or down from this shade selection and try the conventional filter plates as well as the "gold" lenses, or if you are using an auto-dark be sure that all of the cover plates are in good condition, this would go for any of the filters you try. Welding on the 16 ga. materials would indicate an amperage range that would probably allow you to go as low as a #9 filter shade if you wanted to, but I would be reluctant to go any lower than that. These suggestions are certainly only my personal opinion and all other suggestions should certainly be considered too. As you try different things though, do so one at a time so that you can truly determine what is better and what is worse. Best regards, aevald

By 19Slade52 (*)

Date 12-04-2007 14:23

Thank you , Allan!
I'll try your suggestions TODAY!
I hadn't had the opportunity to but a gas lens, but can do this am, and buy some acetone & new brushes.
Had never considered going w/ a DARKER lens, but will try ANYTHING at this point to better see the puddle.
Will try to determine match of base/filler materials.
Again, many thanks for your valued insight & suggestions,
Slade

By 19Slade52 (*)

Date 12-05-2007 00:30

Hey Allan!
I achieved much improvement today with the changes, MANY THANKS FOR YOUR SUGGESTIONS, but I DID stop & buy a #8 lens today after my practice, just to see if that might help tomorrow, because I still can't see the BACK of the puddle, only the FRONT, and I am not STACKING my puddles very NEATLY... they are WANDERING because I can't see the RESULT of what I am depositing, only the PROCESS of deposition. Like I said, I have a long row to hoe...
Thanks again, Slade

By aevald

Date 12-05-2007 01:20

Hello Slade, glad to hear you are making progress. Your seeing issues may also be attributed to your posture while you are welding. I try to position my head so that I am looking in from the end of my weld joint and progressing towards my head. Also, if you are using the gas lens type cup assembly you can possibly cheat the tungsten stick-out just a bit, in normal scenarios where a butt weld is being done, around a 1/4" stick-out will work fairly well, with the lens you can probably increase this to around 3/8". For fillet welds a bit more stick-out is generally tollerable due to the capture of the shielding gas by the parts being welded and up to 1/2" will often work well, here again you can fudge a bit and likely go to around 5/8" in some instances. Whatever you end up with in regard to stick-out, watch the bead color to insure you haven't gone too far. When that happens you will notice the end of the tungsten will blacken after welding has ceased and the color of the finished beads will start to go from the nice straw colors more towards the grays and dull color. Also, always remember to run enough post-flow on the shielding gas timer(this time should be long enough so that the tungsten will maintain it's shiney appearance once welding has ceased and will be longer as the size of the tungsten used increases) and hold the gas cup over the end of your bead until it has timed out. This will keep the end of the bead from turning black or gray and also help to capture and hold the post-flow gas on the end of the tungsten to keep it from burning up and oxidizing.
If you get a chance, use the search function on the forum here and check out some of the previous posts that are on here discussing GTAW shielding gas, gas lens, weld deposit colors, and some of the other topics that relate to just the sort of questions that you have asked. There are a bunch of highly skilled contributors here that have given tons of information that could possibly answer any questions you have or would like clarified. Lawrence is one of these gentlemen, Tommyjoking is another, ssbn727(Henry), another, Kix, I could go on and on. All of these folks and more are available to help you out. Stay tuned and ask away. Best regards, Allan

By 19Slade52 (*)

Date 12-05-2007 12:40

Thanks for the tips, Allan!
I was NOT aware the tungsten could potrude quite so much, but I'll give it a go!
I try to draw the torch towards my body at an angle of about 40 degrees from the left - right perspective, and also try to get the work close to eye level.
I'll definitely search the forums you suggested.
Thanks again, Slade

By Stringer (***)

Date 12-07-2007 05:13

Try laying the torch over, and keeping the cup against the weld as you go. I use a lens, and not so big a cup as you might think. I've had no luck with a monster cup. I use a number 9 green lens. I've tried an eight for a brief moment and I am convinced this is too light. I don't care much for auto darkening unless I'm tacking repetitively. I am 53 and weld at least ten pounds o/f 308l 1/16 rod on 16 gage to 10 gage stainless every month. Also you might consider being skeptical of the quality of your gas. If your technique on a quick 1/4 inch t-joint of 304l fails to produce a bright gold then check connections and experiment with gas flow rates. Wide open will not produce turbulence enough to bother a weld in my experience, but it is certainly wasteful and unnecessary. Middle of the road works best for me. I use a 3/32 2% tungsten in a 20 series torch. As for machine, I believe anything made in our lifetime will work fine, although I admit I use modern and expensive equipment, but mainly for comfort of the foot pedal and the quiet fans. I only need high tech for aluminum. The pulse is cool, but is hard to watch and shortens my day. I hope this advice helps... I sure know how much trouble it is to fight something....

By 19Slade52 (*)

Date 12-12-2007 19:32

Thanks for the tips Stringer! Sounds very encouraging!

Slade

By Tommyjoking (****)

Date 12-13-2007 08:22

Slade there have been some thoughtful and intelligent responses here....I will add my $.02 anyway.

Heatsinks are great especially when you need 100% welds on light materials. As mentioned thick aluminum makes a great heat sink and so does copper. Problem is they let you get by with too much heat input so its a crutch and does not force you to learn temperature control. However if a machine is not capable of the heat input you need thats a good solution to solve it.

Greyed welds on steels can be to little deposition rate, too little gas, too much gas causing turbulence and introducing oxygen, way too slow a travel speed causing overheat or boiling, or simply too much amperage. In my experience observing others weld too much amperage is the biggest and most common. A lot of times a filler that is too small will cause this problem with those new to tig. If after running a pass your weld is greyed and has a starcracking or burst pattern of lines in your puddle you are applying too much heat and need to back off probably about 20%

Your problem not being able to see what you laid down as its cooling behind is also common....too light a lens and often all you see is the gas being ionized and little else....too dark a lens and you can not see the radiation from the cooling puddle behind the lens. I became so frustrated with this scenario and having to change lenses that I opted for a high quality auto lens with infinite adjustment strictly for tig work. The lens/shade depends on the amount of current you are applying as well as your viewing angle. For most light stainless and steel I will be somewhere close to a 9 14ga and up closer to a 10. But regardless of your shade you should not burn your eyes as the ultraviolet is filtered regardless of shade with a quality lens. Discomfort comes from eyestrain related to brightness and how hard your trying to focus. There is no good answer here except you have to find a shade/and or equipment that allows you to see what you need to see to lay your weld down.

I like what was said about stickout here......you can stick that tungsten out as far as you need too as long as you can tell the weld is still getting gas coverage adequately. On fillets I will use quite a bit a of stickout so I can see what I am doing. Too big a tungsten on anything but aluminum sharpened well is far preferable to to small a tungsten. Selecting a tungsten size that will hold up and not overheat will come with experience and become second nature.

Travel speed is also something that needs to be learned thru experience...it is directly related to thickness of material, filler size, heat input and avaliable gas coverage as well as backing or lack thereof. But one rule of thumb you must adhere too is you cannot outrun your gas coverage....thats why trailers (long gas tubes behind your cup) were invented.....to allow a tig welder to lay it in faster and hotter without compromising the cooling puddle behind the cup. My personal advice is this what you see thru your hood is black and cold before it gets out of the little red circle of ionized gas on your weld joint. Now depositing rod faster can aid in quicker cooling of the puddle but it can also inhibit fusion and penetration...balance is key here. That balance can be found in your foot pedal and there is no substitute for the ability to manipulate it well.

I wish you best of luck.
Tommyjoking

p.s. this is a good post about real world tig problems