Mig vs Tig for aluminium

[Hood]

Not as much root as I would have liked though but at east it does show that using the polishing mop to buff it is not the best as it rounds the edges and doesn't show the section correctly. With milling the face it preserves all of that.

Going to have to go get some more pickling paste, suppose I have it for about 10years so it has done not too bad ;d

 

[Richard.]

The thing is we are talking penetration as that is the subject here but on a fillet joint like the ones above it’s not the key. The key to a strong fillet is
Correct size leg.
Equal leg
Correct throat to leg ratio (throat = leg x 0.7)
All round even side wall and root fusion
If penetration was key you’d change the joint. Rather than a fillet you’d go for something more suitable like a single or double bevel T joint.

 

[Hood]

The thing that really surprised me in all of this is the current of the Mig, that weld above was 150ish Amps Mig and 190Amps Tig. It may be the Mig is showing an average as it is in pulse but even still I was expecting 200amp plus for 6mm with the Mig.

 

[Richard.]

Pulse is a different animal and always going to penetrate and fuse better than standard Mig as well as reduce overall heat input. 150 amps will be what it is mate it’s the arc voltage that changes. Making your 150 amps more useful penetration wise when it drops momentarily. Super pulse isn’t my forte as I’ve had little to do with it but I believe this is more to do with wire speed and voltage fluctuations.
I’d be interested to see what a standard Mig would do at 150 amps. Can’t imagine it will be anywhere near your results in pulse but only one way to find out I suppose.

 

[Richard.]

The best test is actually the simplest to see which bites the hardest and that’s a simple bead on a plate. Things like direction and joint set up don’t effect the results and a bead on a plate is very clearly all about penetration depth.

 

[Hood]

Have just done a small run in Non-Puse mode, ie just standard spray. Set the thickness to the 5.5mm as previously in the pulse mode and when I looked at the Amps it was 180. Did a weld and it seems to be running around about the 180Amps during the weld so looks like the pulse amperage may well be an average of high and low.

Milled the weld but absolutely no pickle left so it doesn't really show much.

 

[Richard.]

I etch mine with oven cleaner. Works ok.

 

[Hood]

More chance of me having pickling paste than oven cleaner

So too go back to what you said earlier regarding penetration test, is that just on flat plate or are you meaning a but weld?

 

[arther dailey]

thanks Richard as your explanation in(55)was exactly what I was asking about, although I dont know the techie terms,both yours and hoods contributions are always worth reading ., taking time out to post on here is appreciated.arther

 

[Richard.]

More chance of me having pickling paste than oven cleaner

So too go back to what you said earlier regarding penetration test, is that just on flat plate or are you meaning a but weld?

I’d just go on a plate personally. No need for the joint if it’s just a comparison on depth. No point till you get some more slop for etching them.

 

[Richard.]

Obviously without an etch it’s impossible to say but I think I can see all that bottom plate edge there. I would say that’s hardly bitten in at all.

 

[Richard.]

thanks Richard as your explanation in(55)was exactly what I was asking about, although I dont know the techie terms,both yours and hoods contributions are always worth reading ., taking time out to post on here is appreciated.arther

That’s what it’s all about mate.

 

[Hood]

I’d just go on a plate personally. No need for the joint if it’s just a comparison on depth. No point till you get some more slop for etching them.

Yes sounds reasonable and I will give it a go if I can get some pickle or oven cleaner or....

Obviously without an etch it’s impossible to say but I think I can see all that bottom plate edge there. I would say that’s hardly bitten in at all.

It does seem to have very little root penetration. It was not really a good test though for a few reasons. First it was a tiny piece so never really got into it. Second is I have never used the EWM in non-pulse mode so, like everything, it will take some practice to find out what is best.
Doing Mig on such small scraps is not ideal, I would be better hacking up some of the plasma offcuts and get bigger bits to play with.

 

[Hood]

Did a few welds today after I changed to 1.2mm Esab 5356. I also got some pickle but didn't have time to do much, only got one etched.
I wondered what Force Arc would be like on Alu so tried it on some 10mm 5356 and I liked it. I thought it may just be good for heavy stuff but tried on 5mm and it seemed good and then again on 3mm and it was ok as well.
Anyway the one I got cut and etched was a 10mm fillet, one side is ForceArc Pulse, the other ForceArc SuperPulse.

 

[Richard.]

Beautiful even fusion line all round. Those look very sound and well sized indeed.

 

[Richard.]

A tig isn’t going to bite that deep into 10mm plate at 240 amps.
Need 300 to get comparable results I’d imagine

 

[Hood]

Not sure if I will get a chance tomorrow but if I do I will do a mixture of Mig and Tig on 5 or 6mm plate and just see what things are like. Did some runs on 10mm today with the Mig, both ForceArc Pulse and SuperPulse and also just normal Pulse/Superpulse, will etch tomorrow and see if there is much difference between the two.

 

[Hood]

I have tried 3 or 4 times to get a decent etch of the 3mm fillet I did with Force Arc Pulse and Super Pulse but just can't get it clear, not sure why but here it is anyway.

The 10mm plate however came out ok, both pulse, Super Pulse and then with ForceArc to both. Not a huge difference in penetration between the two really.

 

[Hood]

Ok 5mm plate with various welds
1. Pulse Mig 138 Amps
2. SuperPulse Mig 128 Amps
3. ForceArc Pulse Mig 138 Amps
4. ForceArc SuperPulse Mig 128 Amps
5. Forgot to cool plate so probably best ignored but 140 Amps 70Hz
6. Tig 140 Amps 70Hz
7. Tig 140Amps 100Hz
8. Tig 160 Amps 100Hz
9. Tig 160 Amps 70Hz

 

[Richard.]

Have you any just mig. (Not pulse)
At the end of the day this discussion or certainly my thoughts around penetration and fusion mig vs tig was based around conventional mig vs tig.