If you have a bunch of them to do, tack them and then bolt the square plates back to back before welding them out. The heat stresses from one side will oppose the heat stresses from the other side. Unbolt when completely cool and they should come out straight.

Agreed

I'd be on 90amps for sure.

50amps might be alright for boiler tube, but this coupon is schedule 80 pipe. Needs 90 amps min.
Purging is for stainless steel, this coupon I believe is carbon steel so purge not required unless on WPS.

I use 3/32" for everything.

100amps might be a little high. Try 90 amps to start with and work up from there if you need to. Lift start is better than scratch for sure.

Firstly I don't think you'd get that tip to fit a mapp gas bottle. If it's soft solder, the normal mapp gas torch will do it. If it's silver solder, you'll need fuel/oxy to get enough heat into it or at least 2 x mapp gas bottles. My guess is the heaters were soldered in first, then the cap to the b...

First I presume it's some kind of silver solder. If you are using mapp gas + oxygen, ok. If it's just the hand held bottle/ torch, it won't be enough- you'd need at least two of these going around the pipe at the same time. I presume the heater rods come out with the cap. You'll probably find the so...

+1 on the Harris. The most reliable reg I've had.

The Esab is a much higher quality machine compared to the green box. A 200amp power source capacity is all you need for what you'll likely be getting up to.
Good choice.

Listen to the voices, obey the voices. Once you start with the tig it kinda takes over and you want to be able to tackle anything that comes along. And it will come along. Someone will want you to repair his bike or boat prop. If you don't get one now you'll have to bone up for another one later. HT...

These are my settings for 18# ss tubing, autogenous: Pulse 2.5pps Peak Amps 48 On time 50% Background current 50% Electrode 3/32" Cup No.11 Argon 15 L/min (I let you convert to feet) Travel Speed: adjust to ensure a nice bead but fast enough to control heat. Good fitup essential. You won't get ...

My preference is for smooth concrete topped with cheap grey paving paint to seal the cement dust. It wears and gets damaged by spatter and oxy cutting work. Every few years I degrease and recoat. Works for me and looks good.

It can't be both. I wouldn't trust it.

If you have to get another cylinder of something anyway, why not a cylinder of 90/10? It's good for all mig work. C25 is better for short circuit on thick steel but I wouldn't recommend short circuit mig as a process on thick steel, especially with a 250 power source.

No reason why 309 wouldn't do a good job on 304 exhaust. If you don't want to buy in filler that you are not going to use up, go with 309.

There's not that much more surface area in a dished end compared to a flat end plate. The difference is that a torispherical or semi- ellipsoidal end is joined to the shell with a butt weld static joint in tension. A flat end can and will billow subjecting the fillet weld to destructive torsion. In ...

On top of all the above, bin the 4043. Use the suggested filler or 4047.

I reckon you've got something else screwy going on as well. You must have a leak somewhere. Do a soap leak test.

Stop it. I'm getting excited.

Bigger is better.

If spit don't work, try a little oil. Turn it too while sliding it on.

There's a difference between between welder qualification and welding procedure. If you are qualified to weld austenitic stainless steel, you can can weld all of them 304,316,321 etc. No worries. If a welding procedure has been qualified under AS1554, you have weld exactly what the procedure says. A...

Ain't it the truth? There's a-h's in every organization. very glad to hear you've sorted it, I was starting to have bad thoughts about miller. Faith restored.

The PP300 looks like a very good bit of kit but but requires 51 amps on 240v single phase compared to 31 amps for the mm255. So there's that to consider as well. Not sure where you saw that. The Miller manual (one of them) states 41.1A @ 260A/40% duty cycle. By the time you get to 300A output, gues...