[Vince51]

Not new to welding, but never used this technique in the field. Welder put four tacks in as usual, but with a 3/16" gap And no landing. 3 inch heater tubing 9 chrome. He would strike arc on the tack furthest from him and feed the wire in through the gap. Looking through the gap until he had a 3" window. Used the lay wire technique to finish. Made a nice looking root pass while standing in one spot!

Tried this in my shop at home, and its difficult to say the least. Alot of suck back on the bottom for me. I can think of a few places where this would be handy. Anyone have experience with this?

[Otto Nobedder]

Familiar with it, but never tried it.

Locally, it's called "backfeeding", and I can see where it would be useful for a reliable root in a very restricted weld. Doing a reliable root in the mirror can be very challenging. If you can walk the cup by feel, and feed the rod and observe from the front, you may be ahead of the game.

The hot/fill and cap will still be in the mirror, but if you already have a solid root...

Steve S

[Vince51]

My thoughts exactly. No thoughts of IP on restricted welds where grinders don't fit. Found a few videos of it, but they lack puddle views. Would love to try this on aluminum pipe after I develop some skill with it. For now its just the mirror..
I'll search "back feeding" on the net

[Weldlikehoneybadger]

I do back feeding every day, it just takes practice. Looking through the gap is harder than being down there and look from the side. I weld hot on the overhead.

[Vince51]

Seems backfeeding is done more in the south. Louisiana, Texas, and etc. I've worked mostly in the north so its new to me.

What I've learned so far is feeding the wire at a 90 degree angle to the puddle causes me to stick the wire, or push it through the puddle. I'm sure it's done all the time tho. Less angle the easier it gets for me. Im running 90 amps and 1/8" er-70. On another note a 3/16 gap is still to narrow for my auto shade to darken reliably. Strictly practice and sharing info here. Might post a pic or two soon. Still rather lay wire right now.

[Alexa]

Vince51.

What do you mean by: "On another note a 3/16 gap is still to narrow for my auto shade to darken reliably."?

Tanks.
Alexa

[Otto Nobedder]

Alexa,

The light when peering through a 3/16" gap doesn't hit the sensors on your hood when you're in close enough to see what your doing... the arc light is projected through a narrow slit. This is a good place for a plain ol' fixed-lens hood.

Steve S

[Vince51]

Yep the sensors on my hood don't pick up enough light to darken. I just use the 2x4.Singles , but a better lense might work. Plain ole fixed lense works well. Can't see where your starting anyway.

[hacadacalopolis]

Major thread revival!

I have been searching the net looking for videos on the "how to" as well. I have learned strictly lay wire on a 1/8" gap for 6g. Places that i might be traveling to I hear most Backfeed the pipe with a 5/32" gap and 1/8" wire.

I have tried doing this twice and found it to be very difficult. I could not fathom the wire feeding through my fingers while walking the cup or freehand. My school time will be closing up on me soon- But this is the last thing i want to learn. As well as, " Look through pipe" method.

Any pros to help me with how they intrepret the Backfeed with their hands

Just also noticed this is under aluminum subheading. I was hoping to get feedback for steel.

[weldin mike 27]

Don't worry mate, its all for tig, no matter what material. The heading is a little miss-leading.

Mick

[79jasper]

On steel, to get root reinforcement on the back with the lay wire, I have to slightly shove the filler into the puddle. Takes a lot of practice (I need more) and many tungsten resharpenings later, but eventually you'll get it.
I have no experience with through the pipe, but would like to try one day.

Sent from my SM-T537R4 using Tapatalk

[wheresmejumper]

There is no secret or trick to it, just being able to feed the filler rod steady and accurate.
A bridge tack at 12 o clock will let you rest the filler rod against it if you need to steady it more.
bevel to bevel with your torch, keep on the leading edge of the molten pool with the filler.dont follow the torch with the filler, keep it centre.

[hacadacalopolis]

There is no secret or trick to it, just being able to feed the filler rod steady and accurate.
A bridge tack at 12 o clock will let you rest the filler rod against it if you need to steady it more.
bevel to bevel with your torch, keep on the leading edge of the molten pool with the filler.dont follow the torch with the filler, keep it centre.

Resting the filler rod was something I wouldn't have thought of.
I also was notified of most likely remote foot amperage control. < This can also be done on regular output settings without the foot pedal, right?

[Mongol]

https://www.youtube.com/watch?v=UKaPIpxIneE

Welding starts at 5:10.

[wheresmejumper]

Resting the filler rod was something I wouldn't have thought of.
I also was notified of most likely remote foot amperage control. < This can also be done on regular output settings without the foot pedal, right?

ive only used the technique on carbon and stainless, I dont think there is much need for a pedal with them.i would imagine fancier metals might benefit with one though.

[hacadacalopolis]

Last week i could not grasp the concept of how to steady and place the filler wire. After a couple of days I think i have managed to finally learn how the method works. It is very difficult for me to do, Plus, I have only been able to do this freehand so far... I will try now to walk the root, and see which way is most suitable for me to get better at( freehand or walking cup). You guys will probably be able to find all my restarts, lol

6g 6" sch40 5/32" root gap (top view)

image 2.jpeg (51.82 KiB) Viewed 1440 times

6g 6" sch40 5/32" root gap (bottom view)

image.jpeg (50.32 KiB) Viewed 1440 times

This seamed 6" carbon pipe is literally shit in a barrell, To the right hand side of the top view pic there was over a 1/4" gap in the root. I cannot line the seams up properly because of how badly out of round the pipe is, So i get mismatch.

I wouldnt waste my time to prep it- But I know that i could get a better fit up by cutting it in half with a bandsaw and grinding a bevel myself.

One last note; To the rear you can see my 1/8" root gap. Lay wire. Very much a breeze rather than what I am currently trying to learn.

[79jasper]

Not bad though.
If you line up the seams, the rest should match, if you cut your pieces from the same section of pipe.

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[hacadacalopolis]

Not bad though.
If you line up the seams, the rest should match, if you cut your pieces from the same section of pipe.

Sent from my SM-T537R4 using Tapatalk

Our school has been getting some bad pipe in the last 3 months.
Pipe is cut according to what you say. But when fixed on positioner it will not stay concentric for a true bevel cut.
No matter how times we line it up it will still cut with waves.
The join at the seam is very warped coming from the factory

[wheresmejumper]

Nice, you are making it look easier than it is to pick up.
misaligned pipe is a nightmare, but it improves you more