Welding Tips and Tricks

so i bought a old school transformer mig quite recently and it came with a bottle of co2 welded alright except for the fact it was welding sheet steel. so i finished the bottle and then went and bought a bottle of argo/co2 mix but i am now getting extremely porous welds even though i can feel the gas coming out of the tip of the gun.

now my conclusion is that there is a leak somewhere and it is sucking in air but im unsure.. i want to see what you guys have to say before i go to buy a new lead for it to not be the problem..

cheers nick.

If it was used with straight co2 it will likely have a different regulator or an adaptation to the regulator to stop it freezing. You may have to alter it. Sometimes it can just be a little washer in the fitting near the outlet

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You should be able to pick up a Teflon washer at your local welding supply if this is the case.

Len

I think he may have to remove said teflon washer, as he is going from co2 to ar/co2 mix

mix

hey guys cheers for the replies i have a new argon regulator for the argo/co2 mix so no problem there i dont think

Right. Back to your leak theory then.

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yeah, is it possible to get a leak down the mig lead somewhere?

zedmotorsport wrote:yeah, is it possible to get a leak down the mig lead somewhere?

It is. Inspect it carefully along it's length.

The most likely location in a MIG lead, though, is in the bayonet, where it inserts to the feeder. There are two O-rings here to seal the gas path into the lead from the machine. Make sure first that it is seated fully--this can be a cause, then pull it and inspect the O-rings. As soon as you pull it, you'll understand how it works.

Steve S

interesting, ill have a look today and get back to you, cheers!

Don't forget the possibility you got a bad gas mix.

This happens more often than you'd think.

Steve S

Looks like I may have found the problem... Haha could also be a bad gas mix.. Didn't realise it happened often..

That's a different connector than I'm used to, but I can see where you might have issues...

Steve S

That'll buff right out...........
Glad you found the problem.

That's what my wife said.


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haha cheers for the help guys i can even buy the connector itself so no need to buy a whole new lead!

Ive got a spare mig gun in my shed, but the sticking point is im in Australia....

The connector appears the standard one on every mig I seen & has had a real hard life ! - it looks to missing most of the gas port connector - it's snapped off where the O ring should be that seals it into the machine so yes it's a given you will have gas issues - not sure why it showed up after changing gas bottles - I would think it's coincidence & the connector was moved / disturbed when you changed cylinders - hope you get it sorted.


Here's what it should look like !

Again, learning something new every day.

I've never seen a MIG connector like that.

I can certainly see the issue, though. A question for the OP? Where's the missing bit of the gas connector? Did you extract it from the feeder, or is it MIA?

Steve S

What's interesting is, I can see the piece that's broke off in the picture when I look at it on my tablet with Taptalk, but not when I view it on my PC.

Steve,
It's in the picture, albeit to the right of what you can see on a PC.

Len

Braehill wrote:What's interesting is, I can see the piece that's broke off in the picture when I look at it on my tablet with Taptalk, but not when I view it on my PC.

Steve,
It's in the picture, albeit to the right of what you can see on a PC.

Len

Yeah, all I see is the orphaned O-ring....

Steve S

Otto Nobedder wrote: Yeah, all I see is the orphaned O-ring....

Forum software (depending on the browser) seems to sometimes crop images.

If you do a right-click on the image and then do a 'view image' (or similar.. depends on your browser) you can probably see the whole image.

Bye, Arno.

That is weird - on my computer not even the O ring is showing - I thought the OP was asking if the connector was OK / normal - now I've opened the image I see my comment was unnecessary as he has the missing bit & already knows !

Every Mig here from about 150 > 500 amps uses that connector - all torches interchange on all machines - it's the industry standard - so how does it work the other side of the pond ?

Noddy,

That's quickly becoming the norm in Aus. Although the bernard liners are a pain because they push in and you can't get sufficient back pressure.

Mick

We've had that style so long I can't remember seeing anything else except the Clark / Northern tool / Horrible Fright 90 amp things ( but I don't qualify those as a welder ! )

Not sure what you mean about " back pressure " on a liner ? the liners here are fed in from the connector end & have a brass ferule on that's retained by a screw on cap - not normally a problem - I like this style as it's easy to switch torches - to suit the job.

When you install a liner I was taught to leave it a little proud at the gun end and when you screw in the diffuser or retainer, it pushes on the liner and helps seat it in the centre of the tip. The Bernard ones don't have a screw on ferrule at the machine end, and the liner works out over time.

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