I would usually hit it with pickling paste, as already mentioned here. However pickling agents tends to raise surface roughness. So further sanding may be needed after pickling, it depends... Passivation will occur by itself. Film takes around 3 days to get into it's full strength, just to make sure...

I'm curious about the helium tight welds... What is actually needed that weld will pass helium test? Full penetration and side walls penetration too?

Well it seems that our thread has got out of hands :lol: Anyway just a little job I did this week. I decided to walk the cup, because sulfur mismatch caused bit problems. Mainly undercut. Normally I would use pulsed current and free hand style with joint's like these. WP_20150410_09_40_25_Pro.jpg

Well it can make you look bad welder and it can definitely piss you off! Orbital welders have to deal with problems like sulfur mismatch. Specially when autogenous welding is used. Mismatch can also be noticed by hand welding. Mismatch will lift your puddle and it can affect to the penetration. Also...

It all depends what you weld and what filler you use. As already said here. On aluminium, weld is always weaker than base metal. That is why aluminium welding can be very difficult when demands are high. You have to follow very closely your heat input and purity aspects. Aluminium is not strengthene...

Haha my bad

It won't provide hydrogen embrittlement. That is totally different thing in my opinion.

Will it create Cr2N precipitation? I don't know yet, but I doubt that. It sure will decrease the amount of ferrite in the structure, but that's that I think.

Good catch Steve! IGC (intergranular cracking) is a form of corrosion type, right? Well there is maximum rates for nitrogen as alloying element in each grade and that 2500 ppm is very high! Sure it can do harm in the alloy. After all it nitrogen is very strong austenite and carbide former. Little re...

One of your first videos?

All in all good video and demonstration

Easier to weld when root is wetted and cooled quicker by root gas. Also no slag is formed inside root.

Any sense to use? Perhaps, but usually benefits are so small that it don't make sense to pay for argon you use during root shielding.

There should be given the amperage range to follow. For example 70-90 A. That kj/mm is heat input and it's bit weird that it is given if amps are not. Voltage does affect to the heat input as well, but usually that is not given for hand welding due to change of your tungstens hight. 10 volts refers ...

I posted a topic of this K-Tig about a year ago. It was kind of new thing back then I guess. Now they seem to have a lot more stuff on their website, which is good of course. About the process. To me it's very similar to plasma welding machines. They talk about special torch desing, which tells that...

Not that bad

Zank and Rick already gave you good tips. Try to use less amps too, specially at the beginning of your training. It's always easier to learn when you can slowly move with your puddle and have enough time.

With Orbitalum you are also able to do bevels. Comes handy when you need to get a decent bevel in stainless, 1' inch tubing for example. Those exact machines are really good! We have one that we use for bigger pipes (100-200 mm), but never with sanitary piping or so. It's too big and cut won't be no...

Hi Rick and thanks or asking ;) We have Orbitalum machine. It's really good, but very expensive. Also you have to buy clamping tools for each pipe size. On orbital welding it's absolute must to have squaring machine. What kind of pipe saw do you have? That will do for most jobs, if it's decent one. ...

Well I have to say that I'm very surprised and little disappointed. I read this guide from Miller's site: "Figure 7A shows discoloration on a stainless steel weld caused by overheating, which not only affects a material’s color, but degrades its corrosion resistance and mechanical properties as...

That root is sweet! ;) How you guys get that much reinforcement to root? Especially at 6 o'clock. About those cap passes. Isn't root weld usually little smaller than rest of the passes.... Less heat brought. You already mention about cooling between passes. But think it this way When you start weldi...

Thanks guys! :D So test day is behind and I'm quite confident about welds. These will be only x-rayed and after all basic austenitic should be pretty sure case anyway. Especially that 51 mm. I don't understand why some people struggle with these. Basically you only have to keep steady hand and that'...

Sorry guys, but no photos of carbon pipe :( Test is postponed with couple of weeks at least, because it will be done to higher strength material and that was not available at the moment. However I will still take tests tomorrow on stainless 51x1.2 mm and 12x1 mm pipes on 6G position. Spent some hour...

Thanks Coldman! Btw I checked the difference of S6-S2. It's been up here many times before, but I always seem to forget it :lol: Here: ER70-S2 OK Tigrod 12.62 GTAW Type Carbon-manganese A tripple desoxidized copper-coated rod designed for GTAW of mild and fine grained structural and pressure vessel ...

Welcome to the forum. As already linked. Check out that topic about "different approach to EN EP amperage". There is good write up. Just to help a bit. You already answered to most of your question by yourself. However on AC you don't have "pulse" settings as known on dc. Machine...

Sound familiar to me. I tested these bigger cups on open root on stainless pipe. With massive gas flow from the torch, it created some kind of vortex with out coming root gas (argon). Always messed up my tungsten and suffered from deflected arc. Problem was solved with changing back to number 8 cup ...

Thanks guys :D I welded one stainless valve and had to focus on paper work too. So unfortunately didn't manage to try any tips at all :( But tomorrow I have all day and even evening, so get ready for some pics :D I think I will probably try to walk that cap. In the other hand it's sometimes harder t...

Hello I'm going to take a test on pipe this friday. Haven't weld carbon steel for a while and that's why asking some advice from you guys ;) Joint will be tube to tube in a 6G position and pipe will be regular carbon steel (P250GH) in diameter of 42.4 mm and thickness 2.4mm. (1 3/4" x 3/32"...

Excellent work Zank! :) It's always worth the sweat to spend some extra time with new stuff and trying to learn it as well as possible. This topic really reminds about TIG-orbital welding. There is basic settings that you should follow, but sometimes setting your machine completely different creates...