[tzogistas]

Hello everyone. I ve watched very carefully Jodys videos and listened over and over his tips. That guy is just awesome but i still cant follow him..Even at the basics.. I am welding a full exhaust system for my car from SS304. Manifold is 3mm thick and rest exhaust is 2mm. I ve tried maaaaany many combinations to achieve something but yet not luck.. So any input would be much appreciated. I was thinking to ask jody but if every noob did it he would just quit welding


So here is my setup, as you see i backpurged also the pipes with some good results and some disaster (maybe not enough gas although i had flow pretty enough)



Tack welding 2mm pipes and the ...results..













If you look carefully the whole weld is contaminated except the post flow area



















Tried:
1mm, 1.6, 2, 2.4mm tungstens (Red,gray,blue)
4,5,6,7 size cup
12-50CFH
tungsten from 1-5mm out of the cup
many torch angles
many moving speeds
filler rod 308L 2mm-3mm
WELDING AMPS from 30A-80A (cold welds even had the same problem but much less)

As for practice i spent too much argon (pure) and many many fillers.
The only time i had a little luck was without filler rod and even then when i moved really fast.


Any help is welcome!

[Otto Nobedder]

You are overthinking this. It's an exhaust system, not a steam pipe in a nuke plant.

I weld a lot of light-gauge stainless in my work, including sch. 5 pipe, approx. 16 Ga. Unless you're prepared to weld 3/4" and walk away while it cools, you're going to see some grey welds. It's a lot of heat on a material that can't carry it away before your gas coverage passes. There are solutions, but they're complicated and impractical for exhaust pipe.

You'll be well off to accept this for what it is, and brush your welds pretty with a stainless wire wheel.

Steve

[tzogistas]

Thanks for your input but i have to clear up some things. i ve made 3-4 exhausts for friends with these welds and none failed.BUT i want to learn my mistake and to be able to get that nice rainbow color.just to improve myself.i ve made 2 thoughts at present.1) as you state weld and stop by an inch(too much time and effort) and 2) ""make"" from aluminum foil or something a very big cup to maintain argon shield to a wider area. Just curious how others weld stainlwss correctly..

[mr 32]

looks like your welding hot, are you using and hand/foot amp control?
also i would look at maybe getting a gas lense setup with some large lenses

[tzogistas]

looks like your welding hot, are you using and hand/foot amp control?
also i would look at maybe getting a gas lense setup with some large lenses

If you see the photos that happens also to the cold welds (How much less than 30amps to put?!?) . I ve searched the forum over and over and see that many others and you had this problem so its not me the only one.. But i saw also your amazing welds after the gas lens setup so i m gonna give it a try. Today i spent 1 more hour practicing with no luck except the post gas area. My next step is the gas lens (what do you suggest for a wp26 torch? What cup also?) and smaller than 2mm filler rod. But here comes another question. When i have to weld something thick like 8mm and i must use 2-3mm filler how i can keep then the metal cold enough?

Thanks and i hope to "enlight" me as i see you experienced these issues and got over with great success.

[mr 32]

looks like your welding hot, are you using and hand/foot amp control?
also i would look at maybe getting a gas lense setup with some large lenses

If you see the photos that happens also to the cold welds (How much less than 30amps to put?!?) . I ve searched the forum over and over and see that many others and you had this problem so its not me the only one.. But i saw also your amazing welds after the gas lens setup so i m gonna give it a try. Today i spent 1 more hour practicing with no luck except the post gas area. My next step is the gas lens (what do you suggest for a wp26 torch? What cup also?) and smaller than 2mm filler rod. But here comes another question. When i have to weld something thick like 8mm and i must use 2-3mm filler how i can keep then the metal cold enough?

Thanks and i hope to "enlight" me as i see you experienced these issues and got over with great success.

if your amps are to low and your going really slow to get the puddle melted it can be just as bad as too many amps. jody has a really good video on this with examples, ill see if i can find it. found it http://www.youtube.com/watch?v=mzJR_qkO9wo&feature=plcp

this is what i use, its the 1 1/8th inch pyrex lense



this is the kit i got but for a wp26 http://www.arc-zone.com/index.php?main_ ... ts_id=5097
its the large gas lense set, standard gas lense set and the stuby gas lense set

[tzogistas]

Thank you very much for your info! I like your setup and i think i m gonna give it a shot in the future but for now this is what i could find at my local welding shop. I am going to try it today and hope things get a little better.



Uploaded with ImageShack.us



Also forgot to mention that i took some 1mm and 1.6mm filler to try.

[tzogistas]

....wtf is going on?!?! today i tried a little welding with my new gas lens setup. specs are: wp26 torch. gas lens with 7 cup. 1.6mm tungsten. 1mm filler. 30-50 amps. 6s post flow moving the torch to the entire weld. material was 2mm 304. Results were a little better with the lens but once again i have grey except the last 1-2 cm where post flows work. i also experienced with normal and too much gas flow with no difference. i was only able to get a real nice weld with 20-25 amps and no filler. i am really freakin out because i dont know any more if its my fault.. i was very careful with speed angle of torch heat input etc.. is there any other things i might be missing?!? as i saw many many others with the same problem solved it with gas lens setup.what else can be wrong?it is too frustrating after so much research to get same results..i will try again and post the results.



ps: should i make a trailing shielding to end my issue?

[tzogistas]

There we go again.. after 1 hour welding 1.6. 2.4mm gas lenses here are the results.. maybe i m the onlyone that suck so much at ss....

http://imageshack.us/photo/photo/194/img234if.jpg/

[Otto Nobedder]

I ran into a problem this morning that might be something for you to look at. The problem's not going to be identical, because you started with brand new stuff, but here goes...

I switched to 1/8" tungsten this AM for some heavy sections, and the first (apparently clean) gas lens I pulled from my box was clogged somehow. When I hit the switch to set gas flow, I was able to set it normally, so it took me a while to realize that if I would watch the ball on the flowmeter for several seconds the flow would taper off.

You may have a restriction somewhere in your argon line. Do you have a floating-ball flowmeter where you can actually observe the flow? Or the gauge type where you set it and trust? If the latter, listen to the gas at the nozzle (not welding, of course), and make sure you hear a good solid hiss with the gas turned up. (Actually, listen with either setup-- you may have a leak. I once had a hole burned in my gas line. I'd accidentally laid it across a fresh weld. It didn't leak right away. The rubber got hard and cracked with flexing.)

It's just a guess, but once you've covered the obvious, it's time to look at the unusual.

Steve

[tzogistas]

Thank you very much for your input. it is something at least i can check and its not ok by default.although i dont give it any chance because as you see i have 2 tig welders and 2 torches..also i have both argon regulators and today i had the ball one runing from 8-22 liters per min.as i see this happens because the welding area i leave is still a little red and contaminates despite the huge flow of argon i tested.and i dont think its my amps.today i had 37 amps and by looking my haz i feel i was ok.i dont know even if jody can tell me something different from what you guys tell me. at least i can keep checking things and make myself a little better.


judt a thought: if i was leaking wouldnt and the post flow zone be grey?also hen i turn the flow up i hear real good amount of argon flowing

[mr 32]

how much is the gas flow set at?
i normal run a min of 15lpm for a size 8 cup that should be about around 30cfm

otto might be right it could be a problem with the torch you might want to check it with a Shield Gas Flow Tester

the other thing it might be is if the pipe you used has got sugaring or carbon build up on the inside wall you might be pulling it into the new weld puddle

might be worth getting 5-6mm flat off cut to test the setup on

[tzogistas]

I had 8-22 lpm and no purging.how can i check the shielding zone?as for sugaring shouldnt it affect the post flow area also?i am going to check today for any leaks and we see..

[mr 32]

if the post flow area is shiney/nicely coloured its going to be a sheilding/torch angle/heat issue
if the area is remain red after its left the sheilding area this is what is causing it
if you have done multi pass on the same pipe it could be from all the heat in the pipe making the issue worse.

best way to test the sheilding area have a look at this video http://www.youtube.com/watch?v=9-mnZ2oyCxM&feature=plcp
just sub the Ti for SS

[tzogistas]

Finally i was able to get a decent bead!!37 amps 1mm filler and little to no penetration..i switched yo 1.6mm filler and once again gray.. i ve tried vertical to very little angle (20 degrees aprox) but when it comes to weld something thick like 3mm plus i have to crank up the amps and again the same problem. for sure the area i leave is red but i ve tried to move really quickly with cold weld results.. how can all of you weld thick ss with full penetration and get full shielding until you move on witg the torch?!?would it be extreme to make a trailing gas for my torch??i want to make a video of me welding so i can have your criticism. thanks again all of you

Here are the results.. But what for if i want more heat to full penetrate?

[mr 32]

they are looking good

a joint will get more penetration and the back purge will help with cooling so you can run some more amps
the thickness amps and heat tolarnce are all relevent to each other

ill do a couple of welds with a number 8 and the over size cup so you can see the diffrence if you like

[tzogistas]

they are looking good

a joint will get more penetration and the back purge will help with cooling so you can run some more amps
the thickness amps and heat tolarnce are all relevent to each other

ill do a couple of welds with a number 8 and the over size cup so you can see the diffrence if you like

i would love that just to see how a real welder can do with my setup. i believe i will never reach at the level many of you are because of my non consistency non artistic character but i would like just to be able to weld fair enough for my hobby projects. i m waiting for your welds!!

[Cdavid82]

Hey ive got ur answer, the problem is that your welding just the pipe alone, last week i did a stainless job on thin piping and i was practicing on a thin piece of pipe like you, and the welds were gey also, i went crazy! when you add filler just trying to lay a beed on the pipe surface, 9 out of 10 times it will come out grey, now try doin small circles with no filler with argon at 20cfh and watch the differnece, so weld a chunk of stainless on that pipe or a fitting or something and watch how it changes, i welded o2 senser fittings on the same pipe and the welds came beautiful. My point is that once you add more metal it will soak up heat and the heat wont concentrate as much, that should fix ur problem, Try it!

[tzogistas]

I think you are right but most of my welds are pipes joining and the same thing occurs.i tried what you say on mild steel that i had similar issues and i had a great success. finally i just received my extra large pyrex gas lens and voilaaa!!! everything is perfect!!i will post pics very soon of my results and thank all of you!i cant believe it..my welds are just as beautiful as many of you..almost..hehe. i am very happy i finally solved that problem and i hope this will help others at future too as i saw many experiencing same problems. Just wondering how some good welders achieve good welds just with normal lenses and even with regular collets. i tried many techniques this time like i mention before examining all the parameters and the only way was to weld inch by an inch and let the post flow do the job.. if anyone of you have photos with ss and same issues or nice ones please post and tell your specs.

[Cdavid82]

Nice, glad to here you solved yout issue, So the gas lense does make a huge difference in welding apearence?

[Billbong]

Hi all, the hell of stainless.....many years ago, or so it seems when you're long in the tooth, I used to do stainless steel work for Rolls Royce in UK, that is the firm I worked for did sub-contract for RR, I did the work, etc.

Now all the RR work we did was for re-useable fuel filters for all the various Nato fighters planes and passenger jets that had RR engines in them....around the '75 to 80's era.

One of the filters was for the Concorde, for which we had the sole contract to supply, and I made them.

The method was to assemble the various parts from formed stainless perforated shells and bodies with fine SS gauze SILVER SOLDERED all together,

What this has to do with Tig is not at first apparent.

When you silver solder Stainless you hit one big problem, you have to get the silver solder to wet the Stainless before the whole shebang goes a greyish black and that's your lot.....can't be reclaimed as the SS is ruined.

During the soldering process I used an Oxy/Acc torch, a pretty small one, and you had to get very good to solder and not burn the metal....you burn the metal when it gets to red heat and the flux burns off.

It didn't matter if you recleaned the SS and refluxed and had another go the Silver solder just wouldn't take....a throw away item.

So, you learned to go in quick and not get the SS too hot or it "burned" and that was it.

Looking at the parallel between Tig and silver soldering with Oxy/Acc, you can "burn" the SS and that is probably one of the reasons many have trouble getting the weld pool to form.....the Tig arc is at about 6,000 C, and if you dwell too long in one spot the SS is cooked big time.

Just before I retired in 2000 I worked for a guy who had a submerged arc set-up, and we did 309 or was it 319, can't remember now, but the sub arc welded a continuous bead around a wheel and as the flux fell off the underneath weld was as shiny as a polished SS part.

Sometimes when the wheel was being machined in the lathe you got some bald spots where the diam hadn't gone big enough and I had to stick weld the hollows and remachine them, but the welds were also bright and shiny under the flux.

I can only conclude that the gas/Tig method is at fault when you get a bad weld or cannot even get a decent weld.

All the welds we did with sub arc were of a shiny finish, and never had that bluish brown like I've seen with Tig or Mig.....that suggest to me that the shielding is possibly at fault....I may be totally wrong with that observation.
Ian.

[bryce39]

Try a .040 thick tungsten with a .020 diameter filler rod. The pictures look as your tungsten is too large and you are welding too hot. Switching to the smaller size tungsten should get you in the ballpark to weld those rainbow dimes that you are looking for.

[tzogistas]

The problem was gas coverage.i should show you some new welds but to all might face the same problem just keep your gas there until weld cools..then try welding little colder.appreciate all your help here and lets hope some more will find this useful..

[Tally Tig]

Wouldn't this application require back purging with argon inside the pipe? Or possibly some copper heat sink behind the welds?

[Otto Nobedder]

You'd think so,

But, no.

It's an exhaust system. In reality, it never sees measurable pressure. These welds only need to be leak-proof at atmospheric pressure, and the "sugar" on the back side has no real effect on ultimate strength.

Stainless exhaust systems are usually over-built.

Steve S