first welds, brown deposits

[RaceDiagnostics]

OK, I just got a second hand Clarke 105EN and some gas and decided to build a trolley out of 25mm box, this was my first weld, the metal was clean but there are a lot of brown deposits.

Can anyone say what is wrong, apart from my bad.

 

[skotl]

Not enough gas. What gas are you using, and is it a "hobby" bottle or a larger bottle?

Do you know what kind of flow rate you're producing? Around 12L per minute is the plan but you'll need a gauge that can tell you what it's delivering.
If you don't have a gauge then try turning the gas up a lot more and see whether it makes a difference.

 

[skotl]

Oh one point I was just reminded of on another post - you may have perfectly adequate gas flow but there may be a breeze that's blowing it away from the workpiece? Are you welding in a drafty or outside area?

 

[RaceDiagnostics]

Hi, I was set at about 10l/min, Ill try turning it up a bit, thanks.

 

[skotl]

And there's no chance that it's getting blown away?

What gas do you have? CO2 or Argon mix?

 

[Wedg1e]

I'd have said 10L/min was more than enough indoors.

 

[Paul.]

As Wedg1e, 10lpm is plenty, for the small shroud on a hobby welder even too much, it looks to me like you are dragging rust or some other other contamination from the inside of the box section and its floating to the surface of the weld, dirty / rusty wire gives the same appearance too

 

[RaceDiagnostics]

Odd,I was using a new large bottle of "Argon Hobby 5", a new reel of wire just out the packet, was welding in my garage so no wind and the metal was clean and bright.

I'll try less and more gas tonight.

 

[pedrobedro]

It's oxides formed during the welding process, don't worry about the brown dust. The coke looking weld is more of a problem turn your gas down to around 5lpm indoors as turbulence can cause as much problem as lack of gas. Push the gun away from you for better coverage till you get the hang of welding in different directions and rest the gun on your spare hand to steady it you look like you might have been shaking a bit.

 

[MoreWellie]

I have had too much gas on my Clarke giving pin holes just like there wasn't enough. Typically I have found around 7-8lpm is enough with the hobby torch for this sort of power. I only up it to 9-10 lpm if welding at full power (150 amps)

Could the torch have been too far away from the weld which also reduces gas coverage

Also the weld is stop start rather than continuous. I have found the hobby torch on my Clarke allows me to part pull the trigger and let the gas flow for a second or two before I start a weld which purges the air from the torch

I am an amateur so may be shot down in flames shortly

 

[Ed.]

My two cents on this would be; there are a few things to consider, if the metal is clean then, a gas leak anywhere from the bottle to the tip, or the shroud has a lot of splatter which isn't giving you proper gas coverage or lastly a too high gas flow or too much distance from the shroud to the work, but the last one is unlikely as if that was the case then you would probably have bits of unmelted wire attached.

As you have a fair amount of slag on the weld itself, it could be contamination and or one of the previously mentioned causes as well!

Cheers

Ed.