HI,
I REMEMBER SEEING YOUR POST A WHILE BACK BUT I DON'T REMEMBER ALL THE RESPONSES THAT WERE GIVEN SO SOME OF WHAT I GIVE MAY BE A REPEAT.
LETS ELIMINATE THE BASIC STUFF:
1)I AM ASSUMING YOU ARE NOT WELDING IN A WINDY SETTING
2)YOU ARE USING ELECTRODES THAT HAVE BEEN BAKED AND NOT SETTING AROUND FOREVER.
3)ARE YOU USING ELECTRODES DESIGNED FOR AC USE?
4)ARE YOU USING GRINDING WHEELS OR BRUSHES THAT HAVE BEEN USED ON OTHER THINGS SUCH AS OIL, GREASE, PAINT, ETC.?
THAT COULD BE A PROBLEM.
5)IS THERE GRINDING DUST RESIDUE LEFT ON THE WELDMENT AFTER GRINDING?-COULD ALSO BE A PROBLEM.
6)DO YOU HAVE OIL OR GREASE ON YOUR GLOVES THAT COULD GET ON THE ELECTRODE COATING/FLUX?
7)CORRECT ARC LENGTH USED AND NOT EXCESSIVE?
8)MILL SCALE HAS BEEN GROUND OFF OF THE WELD AREA(BEVELED EDGES, TOP OF PLATES, AND UNDERSIDE OF ROOT)?

THESE ARE ONLY SOME OF THE POSSIBILITIES.

GOOD LUCK,

BRIAN MAAS

Just a guess but is the table you are working on nice and clean?
Bill

I don't think your parameters are permenent i think they are suppose to be a ballpark figure for u to use to start out with. Are you sure porosity is in the root or where is it. It is most common in the root and rarely found in fill passes unless u r using bad practise. U need to eliminate that right off the bat. If u know it is in the root find out where. Run a rod and find out if it runs throughout the bead or if it's just in starts and stops. Restarts on this plate are all the grinding,wich is a whole other ballgame. I grind a runway kind of like how u ground to show us the porosity in that 3g palte i think it was. Then i start down below the runway in some old weld metal for it is to be ground out anyway. DO NOT WELD OR STRIKE AN ARK OUTSIDE THE bevel walls for that fails ya right off the bat. Strike the rod wich can also be a BEEEEEATCH and if it does not strike and sticks u throw that sucka away and get a new one. Strike the rod below the the runway so that by the time you get to the runway the rod is burning good and consistent. If it sticks anywhere in that runway area u must grind all over again for that is where porosity will show up. I've chased my restart back damn near an inch from grinding new runways cause the dam rod would stick right when it started burning through the plate. U just have to laugh and maybe throw a few rods. Also i've used many different rods running this seem and u don't have to use an AC rod. Hell they probably run worse then the regular 7018. The Lincoln Excaliber 7018 is the best rod i've run on this plate. It's the Cadilac of all rods in 7018 open root. Stays lit way better then all the others and lights off quick and easy because of it's grafite tip or something of that sort. Also see if you can get on a machine where u can pulse your AC current. If you have a machine with pulsing capability you can control your AC sign wave and the pnetration will come through pretty easy.pay with the nobs alittle bit and keep that rod choked in the Root opening so you can't see any ark on your side. It doesn't say u can't use a machine with pulse so take advantage of all you've got. Lincoln Square waves are good or Miller dynasty's or something of the sort. There is another guy on here who has done this and will be of some real good help so take advantag of it ask all the question you can! E-mail me if you need more info! Good Luck to ya. R.C.

FIXXXXAH, I have seen this problem before. The biggest problem is a simple one, and that is arc lenght. With a 3/32" 7018 electrode you have to keep an arc lenght of 3/32" or less. If your elctrode angle is wrong this can make the arc lenght too long and you might not notice. If you have run a lot of 6010 or 6011 electrodes you have trained yourself to keep a longer arc lenght and oscillate a lot. Using 7018 requires that you keep oscilllation to a minimum (twice the elcetrode diameter), but many welders can adapt with experience. It also looked like you tried to maintain too large of a puddle on the root pass, and this with a long arc lenght will pull porosity in from the back and well as the front of the weld joint. Your cap pass would fail inspection because, as Kix474 stated, you can not have arc strikes outside the joint. I do not think Pulse welding would help, but only add to your frustration.

I reread your recap and noticed that you have 3/32" root face. E7018 is not a pentration electrode like E6010 or E6011, and that would make the weld joint not compatible with the welding rod. It sounds like the WPS for this test is not very practical. I saw almost no keyhole in the picture of your root pass, and that could only come from not using the correct weld joint with the correct welding electrode. MLM