my first goes at tig welding

[justmental]

exactly my shed has carpet on the floor.
and my mate is building a full tube chassis garage for his corvette and that is carpeted as well

 

[wheresmejumper]

just dont dip the tungsten!

 

[hotrodder]

FWIW rusty 5mm bar with millscale @ ~120A using oxyfuel filler wire (no deoxidisers/not suitable for TIG). Loads of sparks and spitting* and more porous than a sponge BUT note the complete lack of brown soot...



A bead on 3mm angle, not so rusty but plenty of millscale. Same amperage but using plenty of A15/ER70s2 (proper deoxised TIG filler wire), little spitting but the odd spark/bit of spatter being thrown out. The black soot at the end of the bead was what used to be a small piece of masking tape i purposely welded over...



Not big or clever or anything to make a habit of, done to show that the brown soot is not the result of welding over millscale. Tagging/dipping the tungsten will cause it but to get that much of it that consistantly you typically need a MASSIVE gas problem... not using any, using a MIG mix** or a giant gas leak drawing air in- torch assembled back to front/dodgy back cap/dodgy connection anywhere between the regulator output and the torch head including the connections inside the machine. A gas problem will toast the tungsten into a blackened, burnt, oxidised mess

* TIG DC should be virtually silent with no sparks/spatter/spitting
** Can't trust the person you ask for pure argon, many are clueless and either confuse argon with 'argoshield' or can't tell the difference since the cylinder colours were changed and made things less obvious.

 

[pc18]

thanks for taking the time to post those pics and the info, it was a great read. i think i need someone who knows what there doing to have a go with my kit and see how they get on. A friends dad used to have a tig a few years ago and he can hopefully call round soon to have a go.

i seem to have a problem that the tungsten seems to burn away quick and go all blackened, burnt, oxidised mess like you said hotrodder.

 

[hotrodder]

First thing to do is go read the FAQ/tutorial again, especially this bit http://www.mig-welding.co.uk/wiki/The_Basic_TIG_Torch. We've been here before i.e. pages on technique etc and it turned out the collet was in backwards = gas leak = toasted tungsten etc

Go look at the gas cylinder labelling, again had this before where someone asked for TIG gas and/or pure argon but was sold an argon/CO2 mix for MIG and didn't notice. The counter monkey at my local place often grabs argoshield when i exchange an empty pure argon

If they check out and everything's connected up properly (torch -ve) with no leaks at any of the unions (including the back cap O ring) then the next suspect would be the connections to the gas solenoid in the machine.

 

[pc18]

Here's a few pics of my setup to see if I've missed anything obvious.

I've gone over the gas bottle fittings with a leak detection spray and I had a very small leak between the bottle and the Reg, a little nip up sorted that. The gas outlet on the front of the welder seemed ok too. I've not checked the torch its self or the back of the machine and the gas valve yet.

And this is what my tungsten seems to look lile after a short go.

 

[Marc.]

Wow, i am still learning too but my tungsten has never quite looked like that! Is it worth getting one of those pea shooter style flow meters to try on the end of your torch to make sure that you are actually getting the same or similar flow through to the torch that you are showing on your reg?

 

[hotrodder]

^^ Yep, regulators where one of gauges is calibrated to show flow are notoriously inaccurate. Typically they over read IME so it's more about not wasting argon than fixing the problem at hand.

That's what tungstens look like when you forget to turn the gas on/use the wrong gas (something with CO2 or O2 in it) or have a leak, oxidised grey/black all the way back to the collet

Pics #3 & 4 look suspect to me... the gap between the cap and the torch body looks a bit large to me and i can see the O ring clearly. A leak there will draw air in and trash the tungsten. If the leak is the result of putting the collet in backwards i'm thinking it would, at least, partially block the collet too (not something i've actually tried so am guessing there).

I haven't reread the whole thread so may have missed it but can you hear the gas solenoid operate (a click when you press the trigger)? Can you hear/feel gas coming out when you press the trigger* and does the flow gauge needle flicker when the torch is activated?


*press the button before feeling for flow and/or turn off the HF start unless you like a tickle

 

[Will_Davis]

A reg is either 2 stage or 1 stage. A two stage has a little HP reg built in that drops the bottle 220 bar down to a more controllable 100 or so psi.

Then the main adjustable reg takes over.

The number of gauges are not relevant to the number of stages.

Where pressure regulation is vitally important ( like scuba regs or scientific or expensive BOC welding regs ) then two stage regs are used. They provide a more consistent pressure regulation.

Regs have either one or two gauges.

These show (HP one) the pressure in the bottle, the other shows the pressure on the output line. So if you turn on the bottle, the HP will show say 200 bar. The LP gauge shows whats in the hose to whatever is connected. It cannot show flow as there isn't any yet as the torch is off!

Open the torch or whatever and the LP gauge drops to show what is the pressure drop at the noizle of the torch. Still no flow information. Its in PSI!

For flow you need a flow meter - either fitted at the regulator ( ball in tube type ) or better and cheaper at the torch "pea shooter" type.

This is the only system that shows what is flowing out of the torch!

For about a tenner its probably the cheapest, best thing you can buy to help your welding set up

HTH, Will

 

[pc18]

thanks guys yeah first chance i get i will get a torch pea shooter to check the flow a the torch.

i assembled the tig torch following this guide

http://www.mig-welding.co.uk/wiki/The_Basic_TIG_Torch

when i press the button on the torch i can hear the gas coming out of it and when i turn the regulator up and down i can tell more or less gas is coming out of the torch. i have been making sure the back cap is screwed in securely and that the sealing ring isn't damaged. Also when the button is pressed the gauge does flicker.

the first thing i need to do is get one of those pea shooters and go from there i guess. i also need new tungsten lol.

 

[Paul.]

I would suspect that you have put the collet in backwards, as said earlier the gap and the seal showing on the back cap gives it away, just to try and illustrate it I have assembled a torch incorrectly,

This is the collet in the body the wrong way round, if you look at the gas vent holes the thick end of the collet can be seen blocking the gas flow


With the collet the wrong way round the back cap will only screw in a short distance as seen here, the O ring is still visible, exactly as per your picture

 

[pc18]

I'm sure I havnt done that with my collect. The slits in it are on the sharp side of the tungsten.

 

[madkayaker]

Will try to clear an evening in the diary to get through next week and try and help

 

[wheresmejumper]

try a different back cap?
a pea shooter wont give you much info if youve a small leak

 

[pc18]

Thanks Dale that would be much appreciated! I'm keen to learn, I just need some help getting started.

I will have to try the short back cap as I hadn't thought of that. Cheers wheresmejumper haha.

 

[wheresmejumper]

id stick clips on all gas connections too.cant see any on the gas outlet on front panel.
learned that the hard way

 

[pc18]

What sort of clips? Just jubilee clips? The connection on the gas outlet is a very tight fit with the nut on.

 

[wheresmejumper]

use O clips myself,never have small enough jubilee's to hand.
ive had issues with cheap plasticy chinese gas lines.lots of them.

 

[hotrodder]

If the short back cap fits the same then i'd either take the torch apart and post pics of laid out as in the FAQ link and/or go nuts with some leccy tape around the backcap and see if that improves/fixes things as I can't see the O ring being able to provide a gas tight seal the way it looks in the pics. The tungsten you posted a pic of will clean up, it's only surface oxides just regrind the tip for testing purposes

As said O clips are ideal, google shopping in case you're not familiar with them but nought wrong with jubilee/fuel hose clips

My money's staying on the backcap for the moment but if that checks out i'm thinking it's time to pull the covers and check the gas hose connections inside

 

[Marc.]

Sorry to butt in again, i was just musing over the pics you posted the other day pc18, i noticed that your picture of the top o ring where the back cap screws into the torch head... my goodness both sides of that moulding look out of line! (where the two side halves are joined). This would cause a leak in itself wouldnt it if the inside of that isnt perfectly round (where the o ring is sitting). ??