Poor Welds (HELP!)

[RCCossie]

Hello need a little help here. I work as a Propshaft Engineer and have to weld tubing almost everyday. We have very little knowlade on welding but we dont really need to know much as the welding is all done with a rotating system. So all we have to do is set the rotation speed possition the torch then use the settings that we have on a sheet for the wire and volts for that specific size of tubing.

But as of late we have had a little problem, our welds have been shocking (see pics)

This happens almost every weld now . What could be causing this ?

everything is spotless before we weld so i think we can rule that out. could it be dirt of some sort of blockage in the pipe's ?

As i say we have very little knowlage on this

 

[Endacy]

No shielding gas getting to the torch?

 

[malcolm]

Could well be a blockage in the regulator if you get some gas at the start and then none. New regulator if that's the case.

Well worth getting a welding engineer in to sort it and check the set up afterwards.

 

[Chickenjohn]

Yes, my thought, the weld is porous which means the shielding gas had either failed, run out or someone forgot to open the gas valve.

 

[Wozzaaah]

What gas are you using and has the problem coincided with swapping cylinders?
I'd say definitely a gas problem, either insufficient flow rate or possibly even contamination.
That other weld looks very tall and there's an awful lot of soot about.

 

[RCCossie]

Thanks for the speedy response.

The regulator was changed no less than 2 months ago. could this have went allready ?

 

[RCCossie]

What gas are you using and has the problem coincided with swapping cylinders?
I'd say definitely a gas problem, either insufficient flow rate or possibly even contamination.
That other weld looks very tall and there's an awful lot of soot about.

Yes the cylinder was replaced about 2 days ago. the gas is Agrosheild Universal

 

[Wozzaaah]

Ok, two things have changed recently, your reg and your cylinder. If the problem was occurring before the cylinder change then it pretty much rules out contamination so I'd probably look towards your regulator, either the flow setting or a faulty unit.

 

[RCCossie]

nope it was not doing this before the bottles got changed. The gas was leaking slighly out the securing nut on the regulator onto the bottle.

Its not leaking now though. What do you mean by contamination ?

 

[Wozzaaah]

It could be that the gas inside the cylinder somehow got contaminated when it was filled or it could even be that the gas you've got isn't actually argoshield universal, it has been known.

What flow rate are you using? It should be somewhere round 10 lpm.

 

[RCCossie]

yip its 10 lpm. We have had a good welds with it. say maybe 40% of them are good. It seems to be mainly when doing larger welds.

 

[Wozzaaah]

Hmmm, doesn't sound like bad gas then.
I don't really know what else to suggest other than go through all your parameters with a fine-toothed comb.

 

[malcolm]

Is it windy where you are doing the welds? Could be the gas is being blown away.

Can you hear the gas coming out of the torch? The flow meter gauge on the regulator will read a positive value with the gas not flowing, so the flow rate showing on it might not reflect a blockage in the gas solenoid or line. You'd need a pea shooter type flow gauge to show the actual gas flow.

I reckon it's a gas problem of some sort from the photo. Wouldn't trust welds when it's behaving like that.

 

[RCCossie]

We work inside where i dont see it being windy at all.

No cant really hear the gas but our machine is quite loud so that could be why.

(Below are pics of our equipment set up)

Could this earth wire be doing us any harm ?

I dont think this machine has ever been maintained at all. maybe it could do with a good clean.

 

[shenion]

Try releassing the pinch rollers to disable the wire feed. Start it up an see if the flow meter keeps registering the same level.

I had mine drop off after 5 seconds as the reg pressure was set too low.

 

[Tigman]

have you checked the nozzle , open up and have a look at the diffuser ! I changed mine a little while back , it was worn badly and every now and then I had bad welds , once changed perfect welds again !

 

[Welderpaul]

Check the gas hose where it enters the back of the socket where the euro torch is connected. On occasion we have had problems where the wire has tangled up on the feed rollers, heated up and burnt through the small gas hose causing a leak.
This caused us a similar thing to what you are experiencing.

 

[Robotstar5]

I'd look for a gas flow problem, release pinch rollers (as per Shenion post) and listen / feel for gas at the nozzle, repeat a number of times in case of intermittant fault.
A few improvements not related to your problem, paint wall behind machine matt black, remove earth wire from clamp and bolt to machine and secure (chain) cylinder to something.

 

[xboxjoner]

might be worth trying another torch, if you do that and no change you've eliminated one possible cause, it looks like a mb36 torch which will take a good deal of heat but they be over heated, I have cooked a few of these and now changed to a water cooled mb501 but you will need a welder that supports this

 

[Robotstar5]

....and now changed to a water cooled mb501 but you will need a welder that supports this

You can use a seperate water cooler