[CornerStone]

So towards the end of the weld I started getting the results I wanted. Good penetration, good color and stacked dimes look. I did notice that if I tried running 3/32 filler rod I had to get to hot and it turned gray. With about 100-110 amps and .035 filler I got decent results. Just gotta keep practicing

[Rick_H]

With .035" filler your feeding rod super fast, it hate to have that many starts and stops. How many amps are you using, 3/32" should melt easy enough.

[Oscar]

Looks real good, surprised you were not able to get acceptable results with slightly larger wire. Either way, so long as it meets your expectations. Are you cutting it up to check the penetration profile?

[CornerStone]

Same amps for the 3/32 filler, I'm gonna try again with the .035 filler feeding it faster. I knife edged the joint, left about a .035 gap, wire wheeled it, cleaned with acetone, back purged the pipe and verified 18cfh out of the huge Pyrex cup.

[CornerStone]

Oh I'm getting close, first bit of weld so the pipe was cool. Beautiful color and full penetration. The weld is flush with the pipe. Amps set at 160 bit obviously not using that much. .035 filler wire with a tight .035 gap. I think setting up an aluminum heat sink will really help keep the heat down. 20 cfh on the torch with the huge Pyrex cup, back purged and cleaned joint.

[Oscar]

not to be an ass, but I see partial penetration into the root? Parts where it did and parts where it didn't break down the root land.

[CornerStone]

This was a single pass, no root. I think I need a slightly bigger gap and to push more filler wire in the joint. It was on the ragged edge of getting good penetration but I didn't wanna push it to hard.

[gnabgib]

If you are wanting full penetration, then looking at your photo, that's not it. As others have said, 2 passes.

[Otto Nobedder]

I've been watching this topic evolve, while remaining quiet.

It's time to comment.

My ASME B31 test was 2" Sch. 40 304SS in 6G.

The WPS had specific information for the root prep, as well as welding the root pass and the cap.
In other words, the WPS clearly defined two passes, making it "required" in that situation.
That suggests to me this is a preferred method, even when codes don't apply, as these people have been studying pressure pipe for a century or so.

I was curious as to how much success you would have on one pass. I frequently do a single pass on sch. 10 up to 2", and sch. 5 up to 4", but it's difficult to get consistent root fusion/penetration AND cover reinforcement in a single pass on sch. 40. I'm not saying it can't be done; I meet better welders than me quite often. I'm suggesting it's not the best idea for someone below "master" level.

Steve S

[CornerStone]

Thanks for the input guys. I absolutely understand the reasons behind doing 2 passes and for doing a single pass. I guess someone had to say it, only a master welder can get the proper results on a single pass. That's fine with me, it gives me a goal to aim for. I'll be doing some 2 pass joints tonight after work to see how it goes and I'll post them up. The hardest part(I think) will be setting up fixtures that work with 3/32 gaps on the joints and hold them without any high/low on the seams. Again, I really appreciate all the input and advice.

[CornerStone]

Root pass and cover pass. I didn't make the gap big enough and I didn't push enough filler wire in to build it up. The root came out pretty good, I think if I would have built up the root a bit more I would have got a better cover but I'll keep practicing.

[Rick_H]

Why one pass? What is this used for?

[Mr. Moose]

Without identifying any of the well known manifold builders, I have handled and inspected several of the manifolds made by the "best" who show their welds on instagram and the like. The ones that represent that they weld "one pass" schedule 40 with full penetration simply don't get full penetration, which is clear when you inspect their products. Some of them essentially have NO penetration visible on the inside of the manifold.

If you really want full penetration, you will need to two passes to get it right. The first pass can even be autogenous with a knife edge land. The second will give you the fill and "stack of dimes" appearance. You can't get both in one pass without putting far too much heat in the weld. Anyone who says they can should post video of the weld and the interior.

[CornerStone]

I absolutely mean to do 2 passes. When I said i thought I could get better cover I meant the cover pass. The root was very small and that meant I had to push a lot of wire into the cover pass and it just barely got flush with the bevel. You also hit it on the head that people who claim to get full penetration and that really nice cover just doesn't add up to me, I see the manifold collectors that are polished to a mirror sheen which tells me that there had to be 100% penetration or a LOT of grinding out of material to get to the weld for a smooth polish. This weld came out very nice but with more and more practice I know I'm going to be getting better results.

[Mr. Moose]

I absolutely mean to do 2 passes. ... You also hit it on the head that people who claim to get full penetration and that really nice cover just doesn't add up to me, I see the manifold collectors that are polished to a mirror sheen which tells me that there had to be 100% penetration or a LOT of grinding out of material to get to the weld for a smooth polish. This weld came out very nice but with more and more practice I know I'm going to be getting better results.

I think we agree on the concept, but you can never tell about penetration from looking at the outside. You have to inspect the inside to determine whether your weld fully penetrated the material. When it has, there will be a visible weld on the inside that looks similar to the weld on the outside. 100% means that (1) it has been welded all the way through the material, and (2) that the interior visible weld goes all around the pipe continuously, no skips or areas that were unevenly heated...

Getting a smooth cover pass in a two pass procedure is just a matter of practice, which you'll continue to figure out and improve, but getting full penetration requires a two pass method, which is where the manifolds you have seen fall short, because in production settings, two passes takes twice as long and they just don't want to expend that amount of time to do it right.

I assume that you are fully back purging as well and waiting to make sure that the back purge has fully displaced the O2 inside the pipe, or the rest of this discussion is moot.

[Boomer63]

So I tried a shaper bevel and it worked out pretty good, still not getting 100% penetration but it was a gapless joint. Im going to try the next one with a .035 gap since that is the size of my filler wire.

Good choice. Jody has an excellent video on something like this. You will still need to cover the joint to prevent purge gas leaking out - but you probably already knew that. With the joint the same size as your filler, use a lay wire technique and go, go, go!

Good luck and keep us posted!

[GreinTime]

I absolutely mean to do 2 passes. When I said i thought I could get better cover I meant the cover pass. The root was very small and that meant I had to push a lot of wire into the cover pass and it just barely got flush with the bevel. You also hit it on the head that people who claim to get full penetration and that really nice cover just doesn't add up to me, I see the manifold collectors that are polished to a mirror sheen which tells me that there had to be 100% penetration or a LOT of grinding out of material to get to the weld for a smooth polish. This weld came out very nice but with more and more practice I know I'm going to be getting better results.

BPAutoSports (Alex) is a friend of mine from school. The kid can weld with the best of the manifold builders that are internet famous, but he has a toolset that involves more than just manifolds, which is more than a lot of them care to admit. I watched from afar as he welded a 25.4 spec drag race chassis for one of our teachers, and again, it looked on par with some of the best (two of our teachers at school included). The dude can weld, and gets paid well to do it.

Does he have 100% penetration with 1 pass? I'm not sure, I've never cut one of his manifolds apart to check. Would I trust a manifold that he welded to hold up to the abuse that most 2JZ's get put through? Absolutely.

I will say this, he is a big proponent of consistency and repeatability, especially when it comes to his bevels. I don't know the specifics of his prep, but he rarely welds them as cast and normally puts his own bevel on with his belt sander (with a jig/guide he made up for it) to his liking.

Also, I quoted this post out of all of them because it was the first reply of yours I saw as I was scrolling through

[CornerStone]

My first manifold turned out pretty good. I would say I was getting 95% penetration with a single pass, very mild work with a die grinder and there was no evidence of a joint on the I did of the tube.

[rick9345]

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