![](/mwf/attachments//avatars/13260-9338.jpg)
I'm watching my guys constantly fight running 5/16" to 3/8" 2f fillets with metal core .052 wire. They were using .045 witch was pushing it so I thought it would be easier and more cost effective for us to make the jump to .052. The puddle seams to be to fluid and the bottom toe of the fillet always seams to look like it's coming close to rolling over. It doesn't have the same transition into the plate as the top toe of the fillet witch leads to speculation of lack of fusion for the first few mm on the bottom toe of the fillet. I know what you think and that they're not feeding enough wire, but it still does it and then gets to the point your cooling the puddle off to much to be getting consistent fusion everywhere.
I've thought to maybe try out some all position flux cored wire to keep that top edge where it needs to be and make the fillet look like the cross section of a triangle. I just don't know if I will be able to justify the mess. I then could cut down on the # of rotations needs to position every thing so that it can be welded in the 2f. Before one rotation they could have three sides welded.
I just want to here how some of you justify using flux core over metal core or vise versa.