Where to from here on these welds?

jumpinjackflash · Wed Feb 05, 2014 8:26 pm

I mentioned in my intro post that I now and then get a splintered looking puddle. Kind of think it is getting too hot...not sure though. So suggestions from here are good. Pic 1 is flat plate/tube .090" pic 2 is splinters on a tube of 5/8 .035" pic 3 is just some more practice....pic 4 is of the joints I am working towards joining up. This has to be a good , solid weld...doesn't have to be all that pretty...but must be 100% there. My friend keeps telling me that the weld needs to be kept as small as possible to keep from poking through to the inside and weakening the tube. I am not there yet from my practice welds. Man if Jody had a small one or two day crash course hands on with him...I'd be there to sign up. I think I would learn more in that time than a year anywhere else. What can I do to check my welds? I don't have a way to pull test them....guess I could cut open a few and beat them out on the railroad iron to see what gives first.

jumpinjackflash · Wed Feb 05, 2014 8:32 pm

Here are the joints I am gearing up to weld in sequence......more than one of these.....I'll clean everything inside and out right before I start in on this. Might seem silly but I chemical clean the inside of the tubing too. Acetone after flap wheel outside...then light up.....I am just not ready yet. I was not happy with the bolt through pieces and they will be remade. The main tubes are .625" x .035".

Wed Feb 05, 2014 8:54 pm

"Pushing through" the tube will NOT inherently weaken it.

Excessive heat, however, can, by affecting the hardness and ductility of the tube. The advice to keep the weld no larger than needed is sound, however, the average Joe cannot keep a perfect weld thickness, so a "bit" larger than needed is a good option.

That second picture does confuse me a bit... Looks like rings and rays on a fresh-cut tree stump. I've not encountered that before. Is your machine perhaps shifting to HF Start mode as you tail off? Are you pulling back a bunch as you tail off?

Steve S

jumpinjackflash · Wed Feb 05, 2014 9:07 pm

I have not noticed me pulling away...I always try to tail off slowly and wait until post gas is timed out. Guess I will have to note what I am doing more closely. This has shown up in a few other welds...it is a new machine as I took it out of the box and all. But you never know...maybe I will call up Miller and see what they say or just wait. I know someone has to know this....I am lost. Could it be contamination on something? Like I said before...I am new and will learn this process...with help and more seat time I am sure. Thanks for looking in to my world of strange things. All pointers appreciated ! I will go out and check everything over again....tear the torch down and smoke everything over good. I have gotten into the habit of wiping my filler down too. Trying to weed out anything that can be a problem for me. But your opinion of the welds so far is ?

Superiorwelding · Wed Feb 05, 2014 9:10 pm

First picture to me looks like it is just inconsistent ripples. The second...Never seen that before either. Looks too hot? Are those cracks? The third looks a little to hot. The fourth looks like a good fit up!

Thu Feb 06, 2014 5:49 am

Hey,

What wire are you using? I have seen that on ss tig when the gas gets disturbed by a draft.

Mick

hacadacalopolis · Thu Feb 06, 2014 2:25 pm

I've wondered about this as well, thanks for clearing it up Steve S... I welded ss for the first time on a manifold but I got it really hot. It was black on the edges of the toes and one spot on the inside built up like a speck or a turd.

Is this why a small tungsten and wire must be used, Depending on tubing thickness...
I could not see a good bead form or puddle the way I would want it to with 1/8 tungsten unless the amperage was up there.

Thu Feb 06, 2014 7:33 pm

hacadacalopolis wrote:I've wondered about this as well, thanks for clearing it up Steve S... I welded ss for the first time on a manifold but I got it really hot. It was black on the edges of the toes and one spot on the inside built up like a speck or a turd.

Is this why a small tungsten and wire must be used, Depending on tubing thickness...
I could not see a good bead form or puddle the way I would want it to with 1/8 tungsten unless the amperage was up there.

Yes, generally.

You can do fine work with a fat tungsten, but it requires a long taper and a very smooth grind.

If I were doing a bunch of welds on a set of stainless headers, with, say, .063 wall, I'd want to use a 1/16" tungsten. It's much easier to get a good grind for the job, and have a controllable arc at 35-40 amps.

Steve S

jumpinjackflash · Thu Feb 06, 2014 8:02 pm

weldin mike 27 wrote:Hey,

What wire are you using? I have seen that on ss tig when the gas gets disturbed by a draft.

Mick

I usually have .035" ER70-s2.....and some .045 somewhere. 1/16 ceriated tungsten and gas lens. May very wel have been a draft issue as the shop door was propped open about 2 inches. I also have a gable vent that was open. I noodled with some scrap aluminum this morning before work...just wiped it off and put in a pure tungsten and melted a couple rods to see if I could make a decent bead. I need to practice for me to get better. I think the posts about coolant being an issue with TIG is for real...wandering arc no matter what I done. When it was stable and produced a decent arc it was very close to dipping in. The machine's owner uses green antifreeze....