[ekbmuts]

I'm welding 3/8" SS tubing, 0.035" wall with a stubby gas lens set up, #8 Furick glass cup, 18CFH AR. I'm wondering if I should be using a bigger cup but am concerned it would just get in the way in these tight, tight corners. I think I'd need to much stick-out. But I'm finding that the more argon the better and I'm trying to get my basics set so I can improve my product.

Any input would be appreciated.

Jon

[tweake]

my current go to is the furick jazzy10. that gives me a good long stick out for getting into tight spaces. i like it as it uses about the same gas flow as a #8 cup gas lens (gas is expensive here)
however with smaller pieces you can get away with a smaller cup.
stainless loves gas, but keep in mind it can also cool the part.

another tip if you really want to go the best you can is to purge it, not just inside a tube but externally. set up a purge line with a spare torch with a big cup on it and put that on the other side of the joint. rush kane has a video on it i think.

[ekbmuts]

I'm going to try the Jazzy 10 (just ordered one).

Can you take a look at these pix and give me some pointers? The middle one is rod to rod. The others are rod to tubing. I don't think I'm doing awfully and the welds are holding but man, this takes too long!

THKS!

Jon

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[cj737]

From those pics, you're doing fine. Yes, welding round tube takes a ton of time especially when the diameter is small because you can only weld a dab or 3 then you have to re-position. Real production pros chase around the circumference or use a positioner to roll the material while they hold still (works great, its a production cheat for optimal time and results).

I'd say if anything your filler add looks a bit heavy. Stuff less. Stainless beads tend to be "flatter" or more "shallow". Stainless welds are wicked strong even without filler, so the filler you do add can be reduced from an aluminum style profile.

[tweake]

i'm sure others will give better advice than me.
but first thing is it pays to put something in the pic to give scale, like a tig torch, glove, fingers etc. otherwise what looks really bad in the pic is actually nothing in real life. you can get to fussy on it. hard part is working out what is good enough.
one thing i would do is less step between dabs. i could say smaller beads, maybe closer arc, but i can't tell due to scale.
it all depends on if they need to be pretty or not.
thin material is very difficult and thats always slow.

[cj737]

Tweake those rods are 10mm diameter for scale.

[ekbmuts]

Thanks VERY much for the feedback. Yes - one of my pet peeves is that I can't just weld. It's two or three dabs and then reposition. Couple that with my inherent lack of patience and it's quite trying. It would be terrific if I had the equipment to fit these things up and reposition them perfectly but I don't. So we cope and do our best.

On the rods, right - everything you see is 3/8" OD. Some of it (the "handle") is rod so it's solid and easy to weld. Most of it is 0.035" wall tubing. Welding rod to rod is easiest. Rod to tubing is more challenging but the real work comes when it's tubing to tubing.

I've got a decent bandsaw (Carolina Equipment HV-12) which I use in the vertical position to "notch" my pieces. Using the tungsten carbide burr rig that I made worked but it was too laborious and quite messy with stainless dust flying all over the place. So I just notch on the bandsaw.

But okay - I'll work on less filler. I tend toward a 0.035" rod but sometimes go to 1/16" on the rod-to-rod welds. If nothing else, this is all good experience.

I'm going to post some pictures of the welds once they've cooled so that you can see the heat signature as well as the overall look of the weld before I wire brush it. Wire brushing makes a hell of a difference in appearance so a pic of the welds before I brush it might give you some insight as to argon flow, etc. And I'll include something as a size reference so that you can tell what you're looking at and so that people who may look at this post in the future can tell.

I'll post in a separate thread but I'm going to ask for some advice on straightening the final frames. Being so small and undergoing such dramatic heat input, they tend to warp and while I've tried my hand at heat/flame straightening (with some success I might add), there is definitely more to know. So look out for that.

Thanks again cj737 and tweake. If it weren't for this forum and your patient contribution I'd still be in the dark!

Jon

[Timmy_Tiggs]

I recently welded stainless steel using a #5 cup because I had only welded aluminum for a year and a half and that's mostly what I use. My question is, when you switch to a larger cup, how much argon? I have just used 20psi and 10 second of post-flow and #5 cup for everything, but with SS it gets dirty on the outside of the weld. Are there any guidelines?

[cj737]

I recently welded stainless steel using a #5 cup because I had only welded aluminum for a year and a half and that's mostly what I use. My question is, when you switch to a larger cup, how much argon? I have just used 20psi and 10 second of post-flow and #5 cup for everything, but with SS it gets dirty on the outside of the weld. Are there any guidelines?

20cfh for a #5 is way too high. You should be 7-10cfh at most. When your flow is too high you can create Venturis around your weld. With aluminum, it’s less of an issue but with stainless or Ti, it will be a death knell.

Rule of thumb with a gas lens is 2x cup size. For a #8 I use nearer 20cfh (gas is cheap, time is expensive), for a #10 is use 20, for a #12 I am close to 30cfh, and for a #16 jumbo, I let it rip at 40cfh (almost exclusively used for Ti).

And rule of thumb for Postflow is 1 sec per 10amps of welding current. I also use a .5-1.5 preflow. Don’t underestimate the importance and benefit of preflow. Blowing the oxygen out of the weld area allows a much crisper start, a much cleaner weld, and a faster puddle.

[Timmy_Tiggs]

I did this earlier today while I was at work (I don't TIG at home).
3/32" 2% lanthanated tungsten, #7 cup, gas lens, 20 cfm, 1.2 mm stainless. Fused with no wire. I set the machine to 90 amps and the pedal felt about a third of the way down.
I don't know what the pre-flow setting is -- I didn't think of that.

[Timmy_Tiggs]

I don't know if 20 cfm is more gas than I need for this amperage, but it seems to work fine.
I'll check out what the pre-flow was when I get to work tomorrow.

[cj737]

On an outside corner, a high gas flow won’t matter because the edge splits the argon shielding (which also accounts for the HAZ. But on an inside corner, T joint, it will wreak havoc.

[Timmy_Tiggs]

Thanks, cj.

My pre-flow was set at a little under a second. It's an analog control without a digital readout.
So, that's within the range you described.