TIG Issues

[HWooldridge]

I started in the metal trades over 30 years ago and am fairly competent in several welding processes but I just can't get the hang of TIG. Sometimes, the bead looks OK but for the most part, I can make a prettier weld with an OA torch - and I'm not boasting but my stick or MIG results are usually better than average.

Case in point, my youngest son brought home a stainless box last week for me to patch. This was a deep fryer tank from the burger joint where he works; the material was 18 gauge SS and one corner had split lengthwise about 4 inches (probably from the thermal cycling). I have a nice Miller Synchrowave 250 with foot pedal, which is supposed to be the cat's meow for TIG welding, so I set it up with a 1/16 electrode at 80 amps using 100% argon. I assumed this was 303 or 304 SS sheet and I used 1/8 303 filler rod. At this setting, I continually blew holes in the material and had "icicles" hanging inside the box. After a few minutes coloring the air blue, I ground out the excess and clamped a piece of 5/8 mild steel square inside the corner. This helped immensely but I still contaminated the electrode against the filler rod or puddle at least a half dozen times and made a "mud dauber nest" with the fill. Every time this happened, I would stop and break off the electrode tip then regrind it. Eventually, I closed all the pin-holes and went over it one last time with the torch to smooth out the "mountains". Fortunately, the repair didn't leak (and the cooks at the burger joint were happy with it) but I take pride in my work - it took way too much time and frustrated me to no end.

I realize practice makes perfect but I think my self-taught technique might be working against me - so my question is whether there is any value to the DVD's on Ebay or other sites that claim to teach TIG...or should I simply take a night course at the community college?

[Mainely,Bob]

Both DVDs and courses are worthwhile.The question is do you learn better by watching or doing?

The thing I learned real fast about TIG welding stainless is that it requires purge gas on both sides of the weld.Without that you`re just setting yourself up for failure.

[BIGGUNDOCTOR]

Yep, what Bob said. Purge both sides of thin stainless, or thicker joints with a deep weld prep. It can be as simple as taping something to the back side that will contain the argon, and hold a tube from the bottle.

I did a lot of thin stainless at the Jelly Belly Candy Co., and sometimes it was function over fashion when a packaging line was down = weld it, polish the goobers off, and put it back on ASAP. On a fryer the concern about sterility isn't too high due to the temperatures, but in cooler, or liquid systems they need to be porosity free, so that bacteria cannot get a place to grow. The only way to be sure of that is purging the backside too.

Check your local community college courses out.

[HWHII]

I started in the metal trades over 30 years ago and am fairly competent in several welding processes but I just can't get the hang of TIG. Sometimes, the bead looks OK but for the most part, I can make a prettier weld with an OA torch - and I'm not boasting but my stick or MIG results are usually better than average.

Case in point, my youngest son brought home a stainless box last week for me to patch. This was a deep fryer tank from the burger joint where he works; the material was 18 gauge SS and one corner had split lengthwise about 4 inches (probably from the thermal cycling). I have a nice Miller Synchrowave 250 with foot pedal, which is supposed to be the cat's meow for TIG welding, so I set it up with a 1/16 electrode at 80 amps using 100% argon. I assumed this was 303 or 304 SS sheet and I used 1/8 303 filler rod. At this setting, I continually blew holes in the material and had "icicles" hanging inside the box. After a few minutes coloring the air blue, I ground out the excess and clamped a piece of 5/8 mild steel square inside the corner. This helped immensely but I still contaminated the electrode against the filler rod or puddle at least a half dozen times and made a "mud dauber nest" with the fill. Every time this happened, I would stop and break off the electrode tip then regrind it. Eventually, I closed all the pin-holes and went over it one last time with the torch to smooth out the "mountains". Fortunately, the repair didn't leak (and the cooks at the burger joint were happy with it) but I take pride in my work - it took way too much time and frustrated me to no end.

I realize practice makes perfect but I think my self-taught technique might be working against me - so my question is whether there is any value to the DVD's on Ebay or other sites that claim to teach TIG...or should I simply take a night course at the community college?

In this paticular case I think your set up could be tighten up a bit. 1/16 electrode is a good choice but you could have dropped your amps in half and used a smaller filler metal, say 1/16 or even .045. Another item that will help you is a gas lens instead of a standard collet body it will give you better gas coverage if you are not already using it. A argon backing gas is nice but a piece of copper or aluminum also makes a nice heat sink and wil not contaminate your work.

Taking a class is always a good idea but you can also see if you have someone in the area to come to your house and tutor you in your shop. Check with your local welding supplier to see if they can recommend someone. I do this on a regular basis for people who are having trouble. I can spend a hour or two with them one on one and it make a big difference for them in that time. ;)

[clinton]

If you can weld with oxy-acetylene then you should be able to tig weld as well (both use the same method of adding filler rod)
The school where i learned we made a box using 1x4 strips, tack them all together then weld each side in position, so you get your flat, horizontal, vertical and over head. Then add tubing on each side. We used 16 gage material, this is a good way to practice technique
also part of your problem may be contamination tig welding needs to be clean any oil or rust or paint and you will have issues

[HWooldridge]

Well, my son dropped off another cracked fryer box tonight (the burger joint has several). I turned the heat down to 50a, used a smaller filler rod (1/16)and clamped a piece of 5/8 square hot rolled into the inside corner as a backup. This time, I had success and stitched up both cracks with no holes blown out or other mishaps. The weld appearance was also much improved so I'm seeing progress.

I checked around and there are no local welding classes being offered for the summer so I'll have to wait until fall. It also looks like there is very little offered in TIG - almost everything is stick or O/A. In the meantime, I think more practice is on the menu...thanks to everyone for the tips.

[Guest z.sansoucie]

Nothing quite as exhilarating as seeing your arc go all wonky after contaminating the electrode, eh?

What kind of tungsten were you using and what polarity?

[Bryce Masuk]

Well, my son dropped off another cracked fryer box tonight (the burger joint has several). I turned the heat down to 50a, used a smaller filler rod (1/16)and clamped a piece of 5/8 square hot rolled into the inside corner as a backup. This time, I had success and stitched up both cracks with no holes blown out or other mishaps. The weld appearance was also much improved so I'm seeing progress.

I checked around and there are no local welding classes being offered for the summer so I'll have to wait until fall. It also looks like there is very little offered in TIG - almost everything is stick or O/A. In the meantime, I think more practice is on the menu...thanks to everyone for the tips.

your real problem is grease its in there some how some way,

I used to work on food equipment doing tig welding and even if things were clean they would smell like we were cooking cabbage


you need to wipe the metal really clean if it looks clean its probley not clean enough its pretty much invisible on stainless.

once you get to used to stick or mig, tig welding seems to require much more attention plus the sound doesnt really give you any clue on the weld like mig or stick you can hear whether its welding properly

stainless is also probley the hardest to weld with tig you need a really tight arc distance and hot with quick travel aluminum is pretty easy it took me 2 hours of playing with it to get nice welds in my first day because I already knew how to do stainless to a good quality

[horseshoe182]

hi mr Wooldridge. Tiging stainless can be a trickery thing. I,ve done a bit(lot) . Like bryce said the grease, after dressing the damaged area i would thorougly clean with a metho solution. and then over lap the corners and place very small fusion tacks every 20 to 25mm. if you don,t it will buckle while you weld it. you can purge or use a backing palte/block, i would purge. and run the amps at about what you have ,50. Is 20 gauge 2-3mm? 45 to 50 sounds ok. start in the corners and weld out with one pass only , but it should penerterate if your purging(no holes). the weld shouldn,t be black and this indicates that the weld iis to hot. The thing with stainless is that if it,s welded to hot, the heat will burn out important elements in the steel, and the may cause premerture wear/corriode, however as it,s a grease vat it won,t corriode but the cylconic heating and cooling may cause it to stress crack again. hope this helps

[Scott Hightower]

I find that TIG is more art than science meaning practice, practice and practice. Of the people I have taught welding to, for some reason they find TIG more difficult than most forms of welding.

As mentioned earlier in the thread though, I agree with turning the machine down a bit and be sure to shield the back side of thin gauge material.

Scott
Fab Manager
Welders360

[ajclay]

The oil without saying is a bad thing in any kind of welding. It's got to be clean. When a guy has most of his experience on steel/alum and he goes to stainless he will usually be to aggressive and weld with to much heat. The welds should have a golden color when finished. If it's a possibility of the weld going penetrating all the way through as in thin material, you'll have to rig up some kind of temporary system to get argon to hold on the back side of weld. Thin sheet metal, cardboard and duct tape, what ever works. With thicker material, like 3/16 or more, you don't have to back purge. I did a bunch of stainless the other day, 1/4 in thick material 312 alloy, I used a 3/32 316 rod and about 80 amps. Remember stainless doesn't transfer heat, so you don't have to use as much heat as in steel or aluminum.. And the welds will usually be smaller overall, because, bigger wider welds use more heat, not a good thing. A one pass weld is what you want to do. Once the metal is burnt, black and contaminated, you got problems.. Just my two cents.. AJ

[monstermetal]

I wont beat the 'oil" horse, tis true its imposable to make a clean weld on contaminated material...


And I am not saying this because I think it might be the case, just because it bears saying. The first day of TIG welding class our instructor told us 80% of you will be reasonably good at this, 10% will be great and 10% will never get the hang of it.. Since you can Oxy acetylene weld I am guessing your not in the 10% that get a fail, but its not a skill everyone can master. Mig on the other hand can be mastered by a monkey ( I had my 12 year old son doing production welding with no worries)

I feel like I am a pretty good TIG welder, but I still have issues every once in a while that I cant nail down, Its almost always some unknown crusty stuff that gives you problems, I have welded up aluminum trannys still full of oil, Aluminum oil pans still on the car, even aluminum steering racks dripping with oil... and then wont be able to get a dry clean aluminum bracket weld to stick.... If you have problems with clean, virgin stainless welding, I can say its either the machine or you, if its anything else well who knows what the issue is...

[Nakedanvil - Grant Sarver]

In situations where a backside purge isn't practical, I used to use a paint on flux that you put on the back and does a pretty good job of preventing the crusties. Travel speed and filler are also used to control the heat. The more experience you have, the faster you can go. Be sure to use lots and lots of tacks, usually just fuse without filler. After tacking use a small hammer to close the joint tight. If the joint opens up even a tiny bit, it makes it easier to blow through.

[Willway Forge]

Back up gas, no two ways about it, you need to use back up gas for this weld. (ie. argon on both sides of the surface to be joined).

[Old N Rusty]

i am sure your synchrowave has hi freq , mine does, were you using it? scratch start contaminates from the start. and ClEAN S.S. is a must go with dawn dish washing liq. lots of water rinse then use acetone for final clean and of course purge both sides of weld area good luck , isnt this site GREAT?

[Guest baddog]

Purging the backside with gas will help a lot. I used to do a lot of stainless welding on thin wall stainless tubing for dairies. Every weld was done with purging gas on the backside. Also I had several pieces of brass plate which were invaluable for backing to fill holes and such.