Little crater at the end of each weld

[Mince and tatties]

So I’m mig welding with 1.2 solid mig wire. My welds look fine apart from I’m getting a small hole at the end of each weld, at the point the where I come to a stop.

what causes this and what can be done to prevent it from happening?

 

[Robert Weaver]

Found a few sources that say a similar cause...

Weld pool contraction after abrupt termination of heat source and filler metal.

Solution is to slow down towards end of the weld run or downslope if it's available.

https://www.twi-global.com/technica...t-will-prevent-their-formation-during-welding

 

[Ged93]

Crater ... you can solve if you have the function Crater Filler , which decreased amps and volts at the end of the weld and 'fills' that .

 

[Mince and tatties]

Crater ... you can solve if you have the function Crater Filler , which decreased amps and volts at the end of the weld and 'fills' that .

so does that mean if I weld at lesser heat in general i won’t get a crater full stop? I’m welding thick heavy carbon steel, putting large single run passes, so can’t really go any lower than 28 volts

 

[Mince and tatties]

Crater ... you can solve if you have the function Crater Filler , which decreased amps and volts at the end of the weld and 'fills' that .

How does the machine know it’s coming to the end of the weld though?

 

[Hitch]

As the pool cools, just momentarily pull the trigger to add a tiny bit of extra material and slow the cooling down.

Take a bit of practice to get the hang of when to 'blob' it. Too late and its just a tack ontop of a hole, too early and it wong solve the issue.

 

[Hitch]

How does the machine know it’s coming to the end of the weld though?

When you let go of the trigger basically

 

[123hotchef]

As the pool cools, just momentarily pull the trigger to add a tiny bit of extra material and slow the cooling down.

Take a bit of practice to get the hang of when to 'blob' it. Too late and its just a tack ontop of a hole, too early and it wong solve the issue.

thats what i do just when ya hood flicks to normal mode is about the time!

 

[Ged93]

When you let go of the trigger basically

Exactly , on my Selco mig I can select the feeding mode so 2t , 4t and ramps , with ramps I can can adjust how the machine starts and finishes to weld so soft start , increment , crater filler and so on . So with crater filler I push once the gun and leave and the wire starts automatically to go on , then when I decide to stop I keep pushed the gun and the amperage goes down ( and wire feeding ) filling the crater , when I leave the gun botton it stops to weld . Then crater filler parameters can be adjusted also , only practice is needed .

This kind of function is absolutely necessary for structural constructions or heavy industrial parts as a lot of inspectors ( the majority ) won't accept craters

 

[backpurge]

Exactly , on my Selco mig I can select the feeding mode so 2t , 4t and ramps , with ramps I can can adjust how the machine starts and finishes to weld so soft start , increment , crater filler and so on . So with crater filler I push once the gun and leave and the wire starts automatically to go on , then when I decide to stop I keep pushed the gun and the amperage goes down ( and wire feeding ) filling the crater , when I leave the gun botton it stops to weld . Then crater filler parameters can be adjusted also , only practice is needed .

This kind of function is absolutely necessary for structural constructions or heavy industrial parts as a lot of inspectors ( the majority ) won't accept craters

The majority of sets used in industry don’t have a slope out function, people get around the end crater issue with their welding technique

 

[couchmusician]

"people get around the end crater issue with their welding technique" - This statement says all that needs to be said about the issue.

 

[Munkul]

If you can, you pause at the end of the weld before you let go of the trigger... if you're on an edge and in danger of melting back then let go and restart as described above...

You can generally get around a steel crater problem with technique, but it's more difficult with aluminium... I want a crater fill option on my next MIG, even if I don't do much alloy.