Gas Nozzle, which type for MIG welding ALU ?

[SV1BDO]

The Polish e-shop weldes.de has 3 different types of gas nozzles for the MB-15 torch,
Conical (narrow 9,5mm dia), Standard (12mm dia) & Cylinder (wide 16mm dia). See bellow pics.
Which one is best for welding ALU? Using my poor experience from TIG welding, where a wider gas nozzle produces better results, I conclude that the wider one (cylinder) will be the best for MIG welding ALU, or am I wrong ? Has anybody experience with narrow or wide nozzles ?

 

[Hood]

It is MB36 I use but I find the mid sized one (which you don't show) is best.

 

[backpurge]

Always use the biggest diameter you can, will improve gas coverage

 

[SV1BDO]

Thank you both for your replies. I have to agree with @backpurge, as while I made some tests welding alu with a new double pulse MIG, I had black smoke only on the upper part of the welding (the bottom part was shiny clear), so I think that a wider nozzle will improve gas coverage.

 

[Hood]

Thank you both for your replies. I have to agree with @backpurge, as while I made some tests welding alu with a new double pulse MIG, I had black smoke only on the upper part of the welding (the bottom part was shiny clear), so I think that a wider nozzle will improve gas coverage.

Be interesting to see. I thought that as well and ordered some straight ones in and got a disappointment
Maybe I should have upped the flow but as I already work around the 17-20LPM I thought that should have been plenty.
Maybe the smaller torch will make a difference though so looking forward to the results.