In the last month I stumbled across your KZfaq videos. A little background on me. I started welding in 1990 but in the old days if you didn’t go to tech or what some people say welding school employers wouldn’t even look at your application. So I did. Welded full time and went to school. In my welding career I have had the opportunity to do a lot of things. Full penetration welds that required ultrasound and x-ray inspection. I have done work for the gas and oil industry to welding stuff for drag specialties ( after market motorcycle parts) to working for featherlight trailers on their custom line, car haulers, NASCAR, even Horse trailers that cost more than a lot of houses. The point of this comment is your truly amazing and even as long as I have been welding I have learned from your videos and the new or young welders should watch you vids. If I didn’t live in Minnesota I would definitely take one off your classes for sure. Keep up the great work!!!

One thing to keep in mind, is if you tack the tubing with sufficient heat to penetrate to the inside, you will contaminate the finished weld since no purging is available during assembly. On 316SS tubing (generally about 16ga.,) I would fusion weld a tack about the size of a pinhead, in about a dozen places....the more tacks the better...it keeps the tubing from creeping out of round during welding. Then, fusion weld (without rod) under 50% pulse after setting up the purge. Generally, rather than leave the exit hole for purging, I stick a small piece of steel wool in the exit hole to eliminate turbulence inside. Works beautifully, and you should see nothing but bright, shiny weld on the inside, with no spots where the tacks were. Heat shrinkage at the weld prevents suck back and provides a slightly raised weld inside and out. Takes a bit of practice, but makes pretty impressive,strong welds. Most of my work was in Lab equipment and prototype fabrication in Stainless and Titanium, where back purging was always an absolute MUST.

I do pharmaceutical process piping and every single weld we do in a system is back purged. One tip for setting internal flow rate is to not go too high. You can create a ventrui effect and can actually suck in your weld causing concavity and in my field that means a failed weld due to cleanliness issues and is aesthetically not as pleasing if that matters. Also if you have a large OD tube and you're welding close to the inlet of your purge gas you can use an air tool exhaust muffler to break up the jet of purge gas and spread the flow out and push all the oxygen out.

This was exactly the video I was looking for! Thanks for explaining everything! Subbed 😎👍🏼

this early stuff is the reason i still love you dude. dont change man.. great energy in your delivery brother.

Key concepts for TIG, always nice to have a refresher from a reliable source.

I'm new to your channel and you do an amazing job of teaching this stuff. I've learned alot so far and i even find myself taking actual notes, not just viewing your videos. Thanks man, please keep the awsome videos coming!

Justin you make so much sense , a pleasure to watch and learn from you ! Many thanks

Once again .. I searched for am answer to a topic on which I was clueless and you answered it comprehensively beyond my expectation.

A really clear explanation with well prepared samples - great work and thanks.

I have never welded before and I saw some terms mentioned in a video and you covered everything here and what not to do as well. To be honest, I subbed just for the intro!

Great tip about the weep hole! Not only is it necessary when back purging but also when welding most any enclosed container. As you know, when you weld the air inside heats up causing it to expand. When this happens, as you get to the final sealing weld the pressure buildup from the heated air will do the same thing as in your video (maybe not as spectacularly though)

I gotta say, this is the first video purging was explained so well. Excellent idea to show everyone what happens when you do and do not weld correctly. I had a boss that would get mad and tell me that sugar forms because you're over heating the pipe and would say he's never purged a pipe in 15 years and has never had any problems with durability. (Lies). This video helped a lot, thanks!

Awesome video! You’re very informative and anticipated the right questions! Great work! I’m subscribing.

Just starting my own welding business and I’m knocking off the rust for tig. Great vid, I subbed, thanks I look forward to more content and lessons.

Thank you so much!!! so many answered questions Your information is really gonna help with my stainless exhaust project... I respect the way you teach

Thank you sir for this awesome series of fabrication tips

Very good info, I've learned a lot. Thank you!

I appreciate the effort you put into this video the solar flux is an interesting option for large parts where back gas dams are difficult to apply.

Thanks so much for the time you put into your videos, i hit the ground running when i started tig welding due to the knowledge i gained through your videos 👍

@Fabrication Series - I tried the Solar Flux & Heet, worked great. It immediately prevented oxidation on the inside of stainless tube. Very helpful, not something I would use for food or pharma components because it does leave a black enamel like coating, but good for just about everything else.

Thank you, I needed the refresher course.

On SS tubing , lap joints and butt joints , I have experienced that it is much easier to weld/control the puddle when you BP ! (much easier and edges don't burn away!) It does make a difference, "sugaring" aside! Thank you for the vid Justin!!

amazing video, informative and straight to the point.

Just started doing welding for myself. This is one of many videos of yours. I have watched. Thank you, very helpful

Hey bud! Your a very good teacher. Thank you for your time and effort. It counts. I've been watching welding and fab KZfaq videos for years now. I sum what contribute my career in pipe welding, pressure vessels, and industrial boilers to Jody over at weldingtipsandtricks. But hands down your the best teacher out of all the KZfaqr welding and fab guys! Thanks man! -Ben

Thanks a million for such a great video !

Great job. Learned a lot. Thanks

I do not do, nor intend to, do any automotive welding (especially at 71 yrs) - but I always learn something from every one of your videos! Techniques, procedures, task analysis and planning, reasons for doing something a certain way..... etc. Who knows, the wife may want me to weld up some stainless do-dad in the kitchen and I actually have a dual regulator on my argon tank. Thanks for the professional videos :-)

Happy new year from France my friend, great video as usual :-)

Great Job, These videos Help a ton.

Thank you. Very nice quality tutorial

Awesome video very informative thank you learned alot

great video,...thanks from Portugal...

Very good video, thank you.

i can't accept that he only has 53k subs ...is the public target for this subject of video too low? all his videos are 10/10 hes a awesome teacher and speaker, the video is greatly done , this is not some lame ass dude filming with shitty web cam in a dark room... this and the fab forums is my favorite channels and blv me i got around 600 channels subscriptions from news to games to cnc machinery etc.. please dont stop the doing these videos ever, there is nothing like this on the internet we need this knowledge. you greatly inspired me to start to weld and become a welder for building rollcages and metal fabrication for automotive use... thats how i found your channel, this year im doing it thanks to you!

I use aluminum foil to wrap the pipe for back flow. Also in you don't have a dual reg. you can get a Y at the Welding house and small flow knob and use that. Really Nice Video on this. Must have taken a lot of editing.

Very precise valuable information

Great content very well edited

great video. really professional, loved it

First great video about this problem i can say that.thanks

Great video, learnt lots and explained well 👍

very nice. finally someone explain to understand a person like me that no nothing! thank you. hugs from Mozambique

love your videos, a lot of what we learned here will reflect on our build on our channel!

dude, kick ass video, you explained that so great and kept my attention

obrigado pela dica.. vlw mesmo parabéns pelo canal

Thanks for your knowledge 👍

very well done! good theory, 👍

great explanation!

hey dude you rock. cheerz from brazil

Thanks! Your vieos are amazing! :)

there was an advertisement I had to listen to before I could watch your informative presentation and I thought I'd ask you about it. The topic was Lazar welding. So I thought I'd ask . Thanks

I welded low pressure SS pipe and plate with a flux cored wire process for years and one thing I really wish I tried while I was there was back purging the pipe. At my current job we're getting some of this wire per my suggestion and now I'll get to try it next time we need some SS welded.

great info. thank you

Great video

Great Video.

That solar flux is amazing.

Esta chingon este bato mis respetos

Good video, nice presentation

For the purging, it may help if one remembers that both Argon and Carbon Dioxide (if a mix is used) are heavier than 'air', so it may be a good idea to plan it so one is welding towards the bottom of the parts, rather than the top. May also help when planing how one is going to be introducing the purging gas. Oh, standard treatment for methanol poisoning is ethanol - true! So, AFTER the use of the flux, and the welding, a beer can be medically recommended... ;-)

what brand of purge plugs do you use @the fabrication series looking to buy some , and which do you prefer the silicone one or nylon ? thanks for the great video on back purging 💪

Am I the only one that saw the shark shadow at 7:47?! That’s awesome!

Thanks so much for sharing. I did some welding on stainless tubing today and it was awesome to see the inside weld. Thanks again.

Hey can you come to Australia and teach here? You are the bomb man!

great vid thanks mate

Excellent information as I have been wondering how to go about back purging. Still need to locate a dual flow regulator, as I don't have room for a second Argon tank. Thanks!

Dude the technique required to not dip the tungsten when that blow out went down is masterful 👍

Really good stuff. Thanks for the knowledge.

Cool video, nice presentation. Subscribed. :-)

Thanks for the video, is it possible to use acetone to mix paste? I apologize for the automatic transfer.

Now I see what took you so long, you put a huge amount of work into this video, and it's not filmed while doing a job for money. This was cool! Anyone knows how the "back purging" called in russian, please?

great video very informative

This really is a wonderful video. Thanks for making these!

Great video. thank you. I was going to start welding up my exhaust for my boat. it's a 5" stainless tube. and there will be saltwater in it. Would you back purge?

Solar Flux has two types. Type B and Type A. Make sure your using the proper type for the grade of metal. Also Solar Flux is best used for backing when there is no way to purge the part your welding. Or no way to use your backups. (A piece of copper behind what your welding that is laying flat on the back surface and or a made backup that has holes in it that the argon will pass through to give you the shielding that you need.

Would you use solar flux on boost pipes and intakes. You mentioned it's glassy will any particles get carried into the motor. Do you rather recommend pushing?

The huge rear green screen background footage format is next level compared to any white board... anywhere in 2021

I was a pipe welder for the food industry and I can tell you that getting a correct purge weld is not as easy as it seems. It should be smooth and free of discoloration

I wonder if there's any mileage in making a set of inlflatable toroidal balloon plugs? This may make them easier to push into/pull out of interior situations which are awkward and may reduce the amount of Ar required if they can be moved into closer proximities either side of a weld.

Thank you 🤙

We use to use 315/316 brushed or polished stainless steel plates/sheets, used for pharmaceutical/hospitality, If we was welding two stainless steel plates/sheets, that was butted up side by side together, We use to use a copper plate the length of the join, clamped to the back of where you was welding, which also protected air from getting into and around the back of the weld, giving you the same effect, But we only did this for three reasons, 1 it would take a lot of pure Argon to fill a room, 2 by doing this would probably bankrupt your business, 3 you wouldn’t be able to go into an area that is full of Argon Gas, and if you tried it, you shouldn’t be welding, your weld might not need oxygen, but you do, If it was a sealed tank or ventilation system, we would back purge it using the Argon Gas, making sure that the outlet is at the highest part of the vessel/tank, as Argon is heavy then air, Using a lighter at the outlet port, if it’s a large vessel/tank etc. to check if there is Argon coming out, if the flame goes out, when you place it near the outlet, there’s only Argon gas inside it, 👍🏼

Would a stainless steel car exhaust need to be back purged? It’s not structural and I would be curious if the carbon from engine combustion would coat the inside of the weld and protect it after a short amount of run time? Also is cleaning material before welding with brake cleaner instead of acetone acceptable? Being a mechanic I have tons of brake clean all the time but not a lot of acetone.

awsome video Thank you

Justin. Great talent. Super quality on non standard jobs. One question or challenge. How do you or actually can you weld in an aluminium cylinder head port to add metal to the base of the port. . From the base of the valve to the intake gasket to reshape it into a D port? It is so small and you can't see what you are doing. Do you have a way of doing it?

Excellent. Is there any issue if you get solar flux on the mating surfaces?

Thanks dawg!

Hi, Thanks for your video, it was very helpful, as I have not had a great deal of experience in Tig welding stainless steel tube etc. I'm going to be back purging 75mm stainless steel tube on a job I will be doing in the next few days. Just wondering if you would be able to assist me with a couple questions that I have. Much appreciated, and I sincerely appreciate your advice. Just wondering what gas flow rate do you recommend for back purging over a approximate distance of 3 feet. This weld piece has a number of outlets tacked in place and to be fully welded in position. The thickness of the material is 2mm. What would be the ideal amperage settings for this weld procedure?

What about regular stainless exhaust? Do you back purge that? Or is that up to the customer? I've read about the Solar flux, do you present that as a option for the customer?

I have a terrible memory, so I found that it was easy to forget to turn the purge gas on or off when I'm doing a lot of welds. That's either bad news for the weld or for your pocket since gas is expensive. The solution for me was to have a second solenoid valve for the purge gas that actuates when the torch gas is on. Simple but effective.

Thanks!

I was just explaining this to my nephew and why its so important to do when welding stainless steel

nice video man.

Good info and I nice Conan armbands

Great video! Loved it. most of it I already knew, but you did great with your presentation! Thanks KS much, keep up the great work! BTW what is it you're wearing on your wrists? If I may ask?

All good info, however I wish you would have touched more on your solar flux. Building non turbo headers, and can back purge, but if I can run solar flux on everything before tacking it all together, then I wont have to cut it all up to back purge.

Question. What would be the best way to get a smooth inner surface of the tube? Would I just grind it or is there an alternative method?

Hey! I’m 17 and recently purchased a tig welder, I’m putting a 2.5” 304 stainless exhaust on my car. Is it prone to breaking/leaking if I do not purge it? I do t want to purge it but I guess I could if I have to. Thanks for the awesome vids!!

What about an exhaust for a Diesel engine? Would the ash and soot and diesel coat the weld enough o protect it from the elements that’ll corrode the weld?

Great info if your not sure can't find info on a metal grade run some test piece cut them and look at it

As a young lad, I was fortunate enough to be able to attend a non credit class during the summer months for woodshop, & welding, ...(even got my picture in the paper), & I got really good @ brazing, (so good, I repaired a mortar mixing tub, with coathanger, & flux, but it did take a few hours, & the guy paid me $25.00 on top of me having fun, & told me to look him up if I ever wanted a job @ the Chicago Hts. Ford stamping plant, ... which was about 50 years ago), ... Gotta say your tutorials are filled with great info, right down to the actual doing the project at hand, ... And now I understand how to notch pipe, ... I have a pvc project that. Am about to begin in the next week or so, & your notching tutorial gave me a wonderful idea, ... thanks, ... you got a new subscriber, ... me!