TIG Welding X-Ray Hack! TIG Technique For Pipe Welding!

Summary

In this Extreme Tech channel video, the host demonstrates how to weld a four-inch diameter pipe using a back purge technique for X-ray quality results. He shares tips on purging, using a heavy-duty torch, and maintaining the right temperature and amperage for the welding process. The video covers the importance of clean materials, proper beveling, and gap control. The host also explains the lay wire technique, back fit, and the use of different rod sizes for various stages of the weld, emphasizing the significance of each pass for a flawless finish. The video concludes with advice on post-weld cleaning and the importance of PMI, PT, and X-ray testing for quality assurance.

Takeaways

• 🔥 The video demonstrates welding a 4-inch x-ray quality pipe using a back purge technique.
• 🛠️ Welding is performed on 316L stainless steel, which requires specific techniques and equipment.
• 💡 The welder shares tips on purging the pipe with argon gas for 10-15 minutes at 30 liters per minute for optimal results.
• ⚙️ A heavy-duty torch from the 'Heavy Heated' brand is recommended for its ability to run hot without overheating.
• 🌡️ The video emphasizes the importance of preheating the pipe and controlling the heat input during welding.
• 🧰 The 'lay wire technique' is used for the initial pass, which involves keeping the wire inside and stretching the weld puddle.
• ✂️ It's advised to weld between tacks first and then cut and grind them out to improve efficiency and reduce oxygen contamination.
• 🔩 The welder uses a cup size 8/18/38 tungsten and an air-cooled torch for the process.
• 🛑 The video highlights the significance of pausing before tie-ins to ensure a smooth transition in the weld.
• 🏗️ For the hot pass, a 332 rod is used with 120-130 amps, focusing on stretching and controlling the weld puddle.
• 📈 The final cap pass involves three layers, with each pass overlapping the previous one by 50% to ensure a smooth and even finish.

Q & A

What is the main focus of the video?

The main focus of the video is to demonstrate the process of welding a four-inch pipe using a back purge technique, with an emphasis on X-ray quality welds.

What is the significance of the 'magic number 30' mentioned in the script?

The 'magic number 30' refers to the ideal flow rate for the purge gas in liters per minute, which is recommended for welding pipes of various diameters for optimal purge effectiveness.

What type of torch is recommended for the welding process described?

The recommended torch for the welding process is a heavy-duty, air-cooled torch from the Heavy Heter brand, which can run hot without overheating like regular water-cooled torches.

What is the purpose of purging before welding?

Purging before welding is done to remove oxygen and other contaminants from the weld area to prevent oxidation and porosity, ensuring a high-quality weld.

Why is it advised to weld between tacks before cutting them?

Welding between tacks before cutting them is advised to increase welding efficiency by reducing the need to purge oxygen introduced by grinding, thus saving time and maintaining weld quality.

What is the 'lay wire technique' mentioned in the script?

The 'lay wire technique' is a welding method where the welder keeps the wire inside the weld pool and stretches the pool side to side, which helps in controlling the weld and preventing gaps.

Why is it important to maintain a clean pipe surface before welding?

Maintaining a clean pipe surface is crucial for achieving a high-quality weld as contaminants can lead to defects such as porosity and inclusions, which can compromise the weld's integrity.

What is the recommended amperage range for the hot pass in this welding process?

The recommended amperage range for the hot pass in this welding process is between 120 to 130 amps, which is suitable for stretching and controlling the weld puddle effectively.

How does the welder ensure a smooth start and stop in the weld?

The welder ensures a smooth start and stop by preheating the area, melting the rod, and using a technique that involves dipping the rod and feeding it side to side, which helps in creating a smooth and even weld.

What is the significance of the third pass in the cap of the weld?

The third pass in the cap of the weld is significant as it covers any imperfections from the previous passes, maintains a straight edge, and demonstrates the welder's control over the arc and puddle, resulting in a visually appealing and high-quality weld.

Outlines

00:00

🔥 Welding a 4-inch X-ray Quality Pipe

The speaker introduces the video by welcoming viewers to the Extreme Tech channel and stating the project for the day: welding a 4-inch diameter pipe to X-ray quality standards. They emphasize the importance of using a 316L stainless steel material and discuss the use of 3-inch and 4-inch pipes with 3 mil and 4 mil thicknesses. The video focuses on welding techniques, including proper purging for 10-15 minutes at 30 liters per minute, which is described as a 'magic number' for effective purging. The speaker also thanks Nathaniel Koza for providing a high-quality torch and discusses the use of an ER70S-6 rod with a 400 amp welding machine. They detail the use of an air-cooled torch with a cup size 8/18 and a 3/32 tungsten, highlighting its effectiveness for welding. The video then transitions into demonstrating the 'lay wire' technique for welding, starting from the bottom and working upwards, with advice on preventing gaps and maintaining a clear view of the weld area.

05:04

🛠️ Welding Techniques and Tips

This paragraph delves deeper into the welding process, emphasizing the importance of preheating and maintaining a clean, smooth start and stop to the welds. The speaker recommends purging for 5-10 minutes depending on the spool length and pipe diameter. They discuss the technique of starting the weld from the inside and moving outward, using a 'dipping' technique to feed the rod side to side. The speaker shares their preference for keeping the rod inside the weld until around the 11 o'clock position before switching to the outside. They also mention the use of 109 or 105 amps for the process, highlighting the importance of visibility and control over the edges of the weld. The paragraph concludes with advice on the hot pass, using a 332 rod at 120-130 amps, and the importance of a clean, wide bevel for effective puddle control and weld quality.

10:07

🌐 Advanced Welding Passes and Cap Techniques

The speaker continues with advanced welding techniques, focusing on the fill pass using a 1/8 rod at 150 amps. They discuss the importance of using a buffing wheel to clean each pass, avoiding the need for a grinder except for stop starts. The video demonstrates the process of closing the field to flash, switching to two beads, and overlapping them by 50% to ensure a smooth, hole-free finish. The speaker then moves on to the cap pass, emphasizing the need for equal steps and maintaining a straight edge. They describe a three-pass cap technique, with the third pass being crucial for covering any missteps from the previous passes and ensuring a neat, professional-looking weld. The paragraph concludes with a reminder to perform a PMI test, PT test, and X-ray test to ensure the weld's quality.

15:11

👋 Wrapping Up the Welding Tutorial

In the final paragraph, the speaker wraps up the tutorial by summarizing the key steps and techniques discussed throughout the video. They reiterate the importance of welding between tags, cutting the tacks last, and purging for 10-15 minutes depending on the pipe's diameter. The speaker thanks the viewers for watching and hints at future videos, encouraging them to apply the techniques and tips shared in the tutorial to their own welding projects.

Keywords

💡X-ray

X-ray in the context of the video refers to a non-destructive testing method used to inspect the internal structure of welds for defects such as cracks, porosity, or lack of fusion. It is crucial for ensuring the quality and integrity of the welds, especially in critical applications. The video mentions working on a 'four-inch x-ray quality pipe', indicating the welds are being made to a high standard that can withstand radiographic examination.

💡Purge

Purging in welding refers to the process of removing air from the inside of a pipe before welding to prevent oxidation and contamination of the weld. The script mentions 'purge' several times, emphasizing the importance of purging for 10 to 15 minutes at a specific flow rate to ensure a good quality weld without oxygen-related defects.

💡Tungsten

Tungsten is a metal used to make electrodes in TIG (Tungsten Inert Gas) welding. The script mentions 'tungsten' in relation to the type of electrode used, specifically a 'cup size 8 1/8 38 tungsten', which is critical for the welding process as it helps to maintain a stable arc and contributes to the quality of the weld.

💡ER rod

ER stands for Electrode Rod, which is used in welding to transfer welding material to the weld pool. The video script refers to an 'ER rod' used for welding, indicating the type of filler material being used to build up the weld.

💡Hot pass

A hot pass in welding is a pass made after the root pass to clean the weld and prepare it for subsequent passes. The script mentions using '120 130 amps' for the hot pass, which is a critical step to ensure the weld is free from defects and to set up for the final cap passes.

💡Bevel

A bevel is an angled cut made on the edges of materials that are to be joined, typically in preparation for welding. The script mentions 'bevel' in the context of preparing the pipe for welding, which is essential for ensuring a proper fit-up and a quality weld.

💡Amps

Amps, short for amperes, is a measure of electric current used in welding to control the heat input. The video script discusses adjusting 'amps' to control the welding process, highlighting the importance of current settings in achieving the desired weld characteristics.

💡Cap pass

A cap pass is the final layer of weld that is applied to the top of a weld to seal and finish it off. The script describes a 'three-pass cap', indicating the number of passes used to complete the weld's surface, which is important for both aesthetics and to prevent any contaminants from entering the weld.

💡Feather edge

A feather edge in welding refers to the smooth, gradual transition from the base material to the start of the weld. The script mentions 'feather edge' in the context of preparing the weld area, which is important for a clean and professional-looking weld.

💡PMI

PMI stands for Positive Material Identification, a process used to verify the chemical composition of the materials being welded. The video script ends with a mention of PMI testing, emphasizing the importance of ensuring the correct materials are being used in the weld for safety and compliance with standards.

Highlights

Introduction to welding a four-inch diameter pipe using a back purge technique for X-ray quality welds.

Explanation of the importance of purge time and the 'magic number 30' for optimal purge effectiveness.

Demonstration of using a heavy-duty torch for welding and its benefits over traditional water-cooled torches.

Tips on selecting the appropriate tungsten size and torch for air-cooled welding applications.

Technique of using the 'lay wire' method for welding, ensuring a clean and controlled weld pool.

Advice on welding in sections to prevent gaps and ensuring a tight weld without excessive material removal.

Emphasis on the importance of preheating and maintaining a consistent heat input for quality welds.

The back fit technique for welding small diameter pipes, explaining the process from the top down.

Highlighting the significance of a good purge to prevent discoloration and ensure a quality root pass.

Technique of grinding stop starts for a smooth and clean weld transition, minimizing the need for purging after grinding.

The dipping technique for the hot pass, explaining how to stretch and control the weld puddle effectively.

Importance of keeping the rod inside the weld puddle and the correct angle for optimal puddle control.

Explanation of the fill pass technique using a single pass side to side for a clean and efficient fill.

Switching to a larger rod and higher amperage for the final cap passes to ensure a smooth and robust finish.

The process of overlapping cap passes to create a smooth and even final weld surface without holes.

Final thoughts on the importance of maintaining a straight edge and consistent width for a professional-looking weld.

Conclusion and reminder of the importance of cleanliness, gap, and bevel in achieving X-ray quality welds.

Transcripts

foreign

and welcome to the extreme Tech channel  so for today's video guys uh I'm going to  

work on a four inch x-rays to Strong uh Yuri a  great pipe it's going to be a back perch x-ray  

quality I'm going to show you a couple tricks  and tips uh how to do it uh the best practice  

a little bit advice maybe you can apply this  to any urea grade is pretty much as a 316 as  

you can notice here I got three inch and a  four inch uh three mil and a four mil Gap  

it's pretty much loose one eight uh this is  gonna do we got four attacks three tags in this  

case I'm just gonna leave it to purge couple  minutes 10 to 15 minutes uh that's uh ideally  

and with the purge I go around 30 uh latest RPM  liters per minute this is Magic Number 30 Works  

uh great even for bigger diameter pipe usually  my rule thumb is uh 10 inch and above I usually  

insert like three hoses of purge I like The  Purge for like for 20 minutes half an hour it all  

depends and this is a torch uh I got for my body  shout out to Nathaniel Koza from Louisiana thanks  

buddy I appreciate it this is a really amazing  torch heavy heater brand uh works really great  

uh this torch uh I was looking for a long  time you can really really run hot and it's  

not gonna get really hot like those regular 150  amp storage or 200 amps uh no water cool torch  

so once again thanks Nathaniel but I appreciate  it uh as you can notice 25 22 too is a ER rod  

for uh for tinga it's a urea grid and a big  blue for 400 welding machine so for my torch  

I'm using a cup size 8 1 8 38 tungsten this  is a air cooled torch it's really amazing  

if you guys can check out their brand uh on  a online heavy heater if you got opportunity  

yeah that torch is going to make your life  easier so the little tips and tricks I'm  

going to show you here on this pipe I'm Gonna  Roll in between tax I'm gonna start [Music]  

start on the bottom first this is just showing you  pretty much it's going to be a lay wire technique  

until I hit the top usually I what I do I  usually a section part on the top I always  

go like deep side to side just to prevent you  know grapes and it doesn't take down too much

and this is Lay wire technique just keep the wire  inside and stretch that bottle burn those edges  

always go with the feather edge on my prep  I just kind of have a nice and clear picture  

what's going on you can put a little bit of land  it all depends from the habit and what you prefer

okay as I said I did start on the bottom first and  um and I did in between three and twelve o'clock  

so the first the first idea is uh  just weld in between text don't  

cut attacks yet uh well first in uh  in between and once uh you're done  

then we're gonna switch to grind them  out uh the good idea to do that is uh  

it makes you weld faster yeah you don't  insert any air inside you by using a grinder

pretty much every time you cut attack you gotta  wait a little bit to purge all that oxygen you  

put from your grinder and this way it's uh just  more efficient and a little less time consuming  

so the same idea on the bottom uh preheat  and I'm gonna fit from the top this is a  

back fit here on the bottom pretty much uh on  a small diameter is always uh fit from the top  

or like from 10 o'clock it depends from which  side you are like two three o'clock one side  

or nine to ten o'clock on the other side feet  from the top it's like a back fit technique

give that give that rod in a puddle  stretch that puddle side to side

at the good I like a heavier wool  fits your cup inside uh perfect you  

can uh you can wiggle you can  walk the cup inside the root  

or you can you can freehand whatever it's  easier for you okay now do all those uh was  

in the in between texts are done now I'm gonna cut  attacks out this is the root looks nice looks good  

a good Purge know any discoloration  on the root uh that means that number  

30 that magic number for Purge uh  works good and I highly recommend it  

temperature heat input okay now uh once you've  got all those stacks grind stop starts so you got  

nice uh smoothie feather out all those stop  starts so you can have nice start and stop  

and let it Purge for uh five to ten minutes it  depends from the length of your spool or diameter  

and the same idea preheat I must start melting  at a rod and try to keep that Rod usually what  

I do I always uh try to keep my rod inside all the  way up to the let's say around the 11 o'clock then  

I switched from the outside and started feeding  road side to side just like a dipping technique

the amps I was using here as uh shown on beginning  it was a 109 or 105 amps you can go lower  

I just like the feather edges I I  can see my edges they are just uh  

they they are burning you can wash those  edges and you can see clearly as I said on  

on the top I switch to dipping technique  and for the tie-in I like to pause right  

before the tie-in pause a little bit and Rod as  needed and just go over maybe half inch or so

and that's it pretty much so in this case uh  it's uh they do empty on the root on the root  

path from the outside so I just uh grab a grinder  especially if you got a scratch start then you  

know just in case if you don't uh insert any  any tip of your tungsten and stuff like that  

later in my shown on an X-ray you can just run a  run a grinder just a little bit on a Surface not  

a big deal or even buffing wheel works good  too okay so for the hot pass uh 120 130 amps

this is 332 rod

this is the best part of the welding  hot pass usually especially when you  

got nice and wide bevel heavy wall then you  can really stretch and play with that puddle

it's pretty much simpler guys okay  they rode the 10 15 degrees you  

know in that puddle inclination of  your tungsten is important as well

you know that's uh that's how you  stretch puddle you point that tip  

of your tungsten that's what melts the rod

and then you stretch that puddle new  washing sides side to side motion

you don't want to lift too much up and then just  burns your Rod you know and then every time you  

lose that connection from your puddle then you  got to reconnect and all depends from the material  

then you get the any impurities and uh stuff like  that like in any other any other pipe that's in a  

code guys uh the pipe should be clean clean clean  that's the one of the most important thing beside  

the Gap and uh and the bevel okay same thing  for the for the fill I'm just gonna go one pass

side to side I'll just run one pass here on the on  this pool um as much as I can I'm gonna do my fill  

with a with one well one pass fill side to side  now I switched to trade uh to 1 8 rod 150 amps

and I I got lots of questions about  the amps uh what I shouldn't what you  

guys should do on a hot pass it all  depends how much you can handle guys  

um hot passes it doesn't mean that you got to  go really hot uh the hot pass is just a term  

used for 70 18 after after six to ten root uh to  burn all those uh slag and uh that leftovers from  

six to ten by the hot pass it is recommended  to go a little bit harder you know just um if  

you got like some little pin holes in this and  that you know especially it all depends from the  

material guys but as I said go how much you can  handle you know have to go 120 or 130 or 150.  

as long as it looks nice nice and smooth proper  steps yeah it should be fine okay this is the  

first pass to fail he's gonna ride a buffing  wheel now I'm going to do third pass same thing  

one bead side aside I'll just try  to go walk with uh one bit to try  

to fail and later I'm gonna switch to  the probably cup size 10. or even 12.

so you can have a wider bead as well

but as long as you have a nice  and clean uh base for each pass  

and a good heat and it's just gonna melt your rod  and just leave it pretty much only using buffing  

wheel to clean each pass no use of grinder no  need it except maybe for the for the for the stops

the with this material like uh just uh the way of  

guys show nice and colors it's all uh  you can see that's a little bit hot

but it's inside the weld Zone it's not  the outside on a pipe which is good

okay now almost uh close the field to flash  now I'm gonna switch on the two two beads  

do well beads on a one on each side  overlapping fifty percent of each

the idea is just to cover and make a  nice and smooth feel to flash without any  

holes in the middle

this filter flash just gonna  go over up to that edge

try to make a nice smooth

and try to overlap with that first bait you did

okay that's it pretty much uh failed to  flush I might run actually one in the middle  

and I did a round one in the middle and now  this is the first pass of cap I'll go with a  

three pass cap on this pipe

like always uh first first pass uh try to  have equal equal steps on the side try to  

maintain that uh to have a straight edge take  keep an eye on the the same vid of your steps

that's it for the first pass

now I'm gonna go with the second pass

I'm overlapping here uh 50 of my first pass  

and uh going on the other side leaving enough  room for the third pass you can always use a  

calculation how many bits you're gonna put  on a cap depends how wide is your uh bevel  

but like for the bigger I know guys some guys  go like uh to pass cap a little bit wider uh  

steps I just like have nice and tight everything  I like I like having uh tight steps uh on a my cap

and three pass it should be good enough for  this diameter okay this is a second pass done

all right now we're going to do the  third pass and the last the final pass  

as I said always and I'm gonna repeat  always uh this is the cherry on the top  

the third pass is a most crucial one it's  pretty much important same as the first one  

it covers that straight edge on a pipe but  uh and second pass covers all uh you know if  

you got any misstep on the first pass the  third pass covers the second pass by the  

third pass try to maintain the same width on  the both sides try to have that straight edge

and this is what makes you weld looks really  nice at the end when it's done that's uh that's  

what shows your uh how focused you are with your  welding and your control Arc and puddle control

and that's it pretty much  uh this is a three-pass cap

now the later is uh PMI PMI test ft test and  uh X-ray test as so guys as I said guys uh  

try to try to follow try to follow try try to  implement those steps you know try to weld in  

between tags and then cut the text last and  then you got only one time use grinder and  

finish all tags uh grind all those top  starts and let it Purge 10-15 minutes  

depends from diameter and that's it thanks for  watching guys and see in the next one take care