Getting too much build - wire speed or something else

[v8burbling]

Distance from earth shouldnt make a great deal of difference. Is earth cable heating up when welding at all?

Haven't noticed that.

 

[Chris Stevens]

If earth cable not getting hot would think clamp is all good. Is contact tip new or recently replaced?

 

[v8burbling]

If earth cable not getting hot would think clamp is all good. Is contact tip new or recently replaced?

Relatively recent. It still looks good. I presumed the tip would visibly degrade to indicate it needing changing ?

 

[xmetal]

I think I would open the case and check the internal connections too to make sure they are not corroded.

 

[Chris Stevens]

Relatively recent. It still looks good. I presumed the tip would visibly degrade to indicate it needing changing ?

Remove contact tip and see how much play the wire has in it.............if it seems too much replace it.

 

[v8burbling]

Ah, I was just looking at the external faces of the tip, thinking the wear was due to the arc eroding it. So what I should be looking at is the inner clearance between the tip and the wire.

 

[Richard.]

Hi V8
In order to trouble shoot your problems you need to gain a firm understanding of what each change does to your welding.
Wire speed and stickout has a direct effect on the current you put out. More current = deeper penetration.
Voltage is the heat you put into the wire to burn it off. It's very much mistaken by many that turning this up or down aids with penetration. It has little effect if anything it can work in the opposite way and turning it high can reduce pen. Voltage increases the width of the arc and controls how much spread you want on the run. Finally travel speed. This again confuses many by thinking going slow means I'm penetrating deep. Not the case. Your travel speed simply controls your reinforcement. (Cap hieght).
Based on this. Id say your traveling too slowly. As you say your cap height is excessive and penetration is low.

 

[v8burbling]

The wire carries the arc, the tip just transfers the pixies to the wire. The only place it can do that is inside

Yeah understand that, I'd just not appreciated that the tip wear that you are supposed to look for was the inner part of the tip.

 

[v8burbling]

Hi V8
In order to trouble shoot your problems you need to gain a firm understanding of what each change does to your welding.
Wire speed and stickout has a direct effect on the current you put out. More current = deeper penetration.
Voltage is the heat you put into the wire to burn it off. It's very much mistaken by many that turning this up or down aids with penetration. It has little effect if anything it can work in the opposite way and turning it high can reduce pen. Voltage increases the width of the arc and controls how much spread you want on the run. Finally travel speed. This again confuses many by thinking going slow means I'm penetrating deep. Not the case. Your travel speed simply controls your reinforcement. (Cap hieght).
Based on this. Id say your traveling too slowly. As you say your cap height is excessive and penetration is low.

Thanks Richard.
I'm an electrical engineer so this is interesting.
Things I hear from welders about voltage and current don't seem to follow normal electrical rules and I'm interested to understand it better.

It is current that heats things up (Heat=I^2xR) where I is current and R is the resistance of the circuit
Voltage drives current, increasing voltage drives more current: I=V/R (ohms law)

I had thought that slow travel might increase PEN as the arc has longer to melt the metal at any particular spot.

I've been forced into travelling fast to reduce the build height but I'd rather go slower (to match my lack of skill !) and slow the wire speed down to match but without the wire burning through and losing my arc / popping arc. I think the change to 0.8mm wire may help. Have some on order for delivery tomorrow so looking forward to practicing with that over the weekend. I'm expecting to be able to use power settings 5 or 6 instead of 4 whilst being able to keep the wire speed down and still get that lovely sizzle.

 

[Chris Stevens]

Give the .8 wire a try, but check play between wire and contact tip, as its not impossible for a supplier to give you .8 tips rather than .6, and while the machine would still work with bigger tips it wont be a great deal of good.

 

[Richard.]

I've been forced into travelling fast to reduce the build height but I'd rather go slower (to match my lack of skill !) and slow the wire speed down to match but without the wire burning through and losing my arc / popping arc. I think the change to 0.8mm wire may help. Have some on order for delivery tomorrow so looking forward to practicing with that over the weekend. I'm expecting to be able to use power settings 5 or 6 instead of 4 whilst being able to keep the wire speed down and still get that lovely sizzle.

This is very good. You have a good understanding of what is doing what. Yes a 0.8 wire will help. I personally dislike 0.6 for anything. You understand welding better than I understand electrics so your on to a winner there.

 

[Chris Stevens]

I was forced to use .6mm just once when supplier had nothing else and I was out of wire on a job. Ended up taking it off after getting job done, and changed it next day. Gave it away as I was never going to use it again. Suppose .6mm must be better for some jobs, but to me wasnt much use for vehicle welding work.

 

[v8burbling]

This is very good. You have a good understanding of what is doing what. Yes a 0.8 wire will help. I personally dislike 0.6 for anything. You understand welding better than I understand electrics so your on to a winner there.

Very kind of you, thanks. Shame my skill level doesn't match my understanding yet !

 

[Kent]

I quite liked 0.6 mm the only time I tried it, wouldn't buy it mind