I have some rods that are 7018 48018 3/32. They came in a plastic wraped box I just opened, I tried them on the welder. I had just used some other 7018's and wanted to finish up the job. When i tried them all I got was a few yellow sparks. Half the time not even that. The welder is an old Canadian Tire machine made for them by unknown sources, it was given to me well used and has worked off and on if I keep trying. I'll get a buzz then an arc, 6013 work ok but i keep getting that buzz and no arc. The new 7018's just won't work at all. Help!