Help me judge an aluminum weld

[sea2summit]

My goal is to eventually be able to weld up my own river boat but I haven't done any mig/tig but....

On an aviation forum a industry guy posted this as an example of his work. As a self taught stick guy I'd be telling myself I should grind that off and try again if I want it to stick. Is this a good AL weld?

 

[LittleBill21]

I was under the impression you had to cut a weld in half to see pentation results, to ultimately determine it?

 

[DuckSlayer1017]

If that is done on an inverter welder there needs to be more hf cleaning applied to get rid of the contamination.

 

[sea2summit]

I was under the impression you had to cut a weld in half to see pentation results, to ultimately determine it?

There's all kinds of tests...but there's also many visual indicators of weak welds.

 

[etpm]

My goal is to eventually be able to weld up my own river boat but I haven't done any mig/tig but....

On an aviation forum a industry guy posted this as an example of his work. As a self taught stick guy I'd be telling myself I should grind that off and try again if I want it to stick. Is this a good AL weld?
View attachment 801290

I see a lot of contamination that has floated to the top of the weld. Take a look at the top of the puddle on the rightmost part of the bead. You can see a lot of black stuff. And then all along the top of the bead is visible a lot of black stuff. Then if you look to the left the the parent metal has a bunch of black stuff. I think several things are happening. First, the metal was not cleaned. Second, either the AC balance is not set to clean enough or the metal was just plain too dirty or both. Another problem could be not enough shielding gas or the weld was done in a windy area. My bet is dirty metal as the main culprit. In any case I would not trust this weld for anything structural.
Eric

 

[jjeff]

Been told to clean/ prep aluminium with a dedicated brush that I don't use use to clean steel. So I do.

 

[Smokeydog]

Been told to clean/ prep aluminium with a dedicated brush that I don't use use to clean steel. So I do.

Dedicated stainless steel brush for aluminum.

 

[Rockbadchild]

You are not wrong to think if it was yours you would redo this weld. This black soot is created by multiples reasons (there is 5 main possibility maybe more), I think in this case is most likely the top tubing was recycled and wasn't properly clean beforehand, but it could simply be he was using the wrong gun angle or had bad or too much ventilation. The weld as good apparent fusion on each side and no apparent porosity (I would grind the surface to be sure but there's probably some), it is not very esthetic looking (not straight) the beads are not equal ether (irregular speed) , If I had to rate it I would probably give it a 5 out of 10 at best. If it be a critical structural weld I would redo but if it is what it look like a simple lock-in backet I would polish and leave it, if there is no porosity showing up by the grind or polish.

The 5 possibility for black soot are;

1) Contamination due to poor gas coverage (poor or inadequate gas flow rate or too much ventilation)
2) Insufficient Cleaning
3) Incorrect Arc length (too long)
4) Incorrect Welding Parameters (amperage or polarity)
5) Inadequate Ventilation (Insufficient ventilation in the welding area can cause the accumulation of smoke and soot particles would create deposite of black soot)

 

[jjeff]

Been told after experiencing terrible aluminum welds clean the nozzle of the gun any build up of slag will effect gas flow and make it harder to weld with a spool gun anyway.