Thanks to everyone who commented a couple of months ago. Time has flown! I picked some bits out and had another go today. (Perhaps being more consistent in my practice would help!).
The advice last time I took to be, too slow and power too low.
So I turned up the power - and tried to move more quickly.
First off, I did some more straight welds on 3mm plate. Picture below. Compared to last time I upped the power (and the wirespeed), and with each weld tried to speed up. Penetration is good, plenty of heat going through. In the picture below the bottom weld was slowest and top fastest. With the quickest travel I could see the bright red weld pool getting pulled thin, almost like I was breaking off from the trail behind it, so assume that is too fast? I am also getting a flat section at the end of most runs (runs were left to right in the pic)?
Then I tried welding two pieces of box together as a T, so 2x butt welds and 2 x filet welds. It seemed OK to me, but once ground back one I can still see a bit of a line in one of the butt welds - marked on the last pic, should I worry about this? It has stood up to a hammer test very well...
The advice last time I took to be, too slow and power too low.
So I turned up the power - and tried to move more quickly.
First off, I did some more straight welds on 3mm plate. Picture below. Compared to last time I upped the power (and the wirespeed), and with each weld tried to speed up. Penetration is good, plenty of heat going through. In the picture below the bottom weld was slowest and top fastest. With the quickest travel I could see the bright red weld pool getting pulled thin, almost like I was breaking off from the trail behind it, so assume that is too fast? I am also getting a flat section at the end of most runs (runs were left to right in the pic)?
Then I tried welding two pieces of box together as a T, so 2x butt welds and 2 x filet welds. It seemed OK to me, but once ground back one I can still see a bit of a line in one of the butt welds - marked on the last pic, should I worry about this? It has stood up to a hammer test very well...