Welding problem, think its gas related

[tomfc]

Ok will iv not done any welding with my mig for about 2 weeks, i went to use it as normal today but whenever i welded the weld pool airy (if thats even a word lol) it has small bubbles in it, kind of like if not welding with gas.

Iv used this same Argon/CO2 mix bottle before without any issues and there is still half a bottle left, and even with the tap flowing a high pressure out (i usually run about 4 but i turned it up to about 30 just to eliminate it being a problem where the gas wasnt getting to the weld)

So i thought it might be a problem with the mild steel i was welding, so i tried on something i was welding about a month back (which welded normally before) and got the same bubbly weld.

I had a play with the wire speed and weld strength but it didnt make any difference.

Anyone got any ideas?

 

[Tigman]

is the weld metal clean , ive had this with oil and grease on metal, also take off the shroud n your torch and make sure its clean in side and around the diffuser !

 

[tomfc]

Yes i cleaned the metal up, i thought it might have been an issue with the metal thats why i tried some metal that i had already welded on before but still had the same issues..

 

[Tigman]

take off the shroud on the torch and see if your clean in there my diffuser was non existant so gas was not coming through right caused the same effect !

 

[R Kraft]

Sometimes the hose that carries the gas will break or leak, between the gas valve and the torch.
Robert

 

[arceyered]

Sometimes the hose that carries the gas will break or leak, between the gas valve and the torch.
Robert

I agree sounds like you may be sucking in air check all your connections ,look to see if there is any damage to the torch etc.
you can also, although rarely get a contaminated gas bottle but being as you have used it before I would rule that out.
also to much gas can create weld disturbance and cause perosity and an unstable arc.

 

[TBC]

could be a faulty gas solenoid on the machine also.

open it unclip the wirefeed tensions roller, powerup, press trigger make sure wire does not run. then clicking the trigger on and off make sure the gas is turning on and off.
you can do this by emersing the tip in a small glass of water and pulling the trigger, it should bubble. DO NOT HOLD IT NEAR YOUR FACE IN AN ATTEMPT TO LISTEN. for obvious reasons lol.

 

[tomfc]

Thanks for the replies, i tried to remove the shroud today to find that it wouldnt budge, so in the end i had to cut to off, revealing a massive drop of slag that was blocking the gas coming through, i could hear the gas at the tourch but clearly the gas wasnt getting through to the arc. So i fitted a new shroud and its back to normal again

 

[TBC]

grab yourself some tip dip and use it from time to time. also remove the shroud regularly and give it a clean out with a round file to remove spatter.
especially important when welding coated steels and doing lots of downhand work, cleaning your gun is a good habit to get into cos if your doing a long run and the weld goes porous you would end up having to dig the whole thing out, a right ass pain on a round flange lol.