6010 for the root pass, then 7018 for filling and capping, great combination. 6011 will make an excellent job too for the root pass, plus it's a bit easier to work with than the 6010.

@@luillierstephane1463 what difference in 6010 and 6013? haven't use 6010 before

@@ykcajkom687 6010 and 6011are cellulosic coated rods, 6013 is a rutile coated one. 6010 and 6011 have better penetration in the root and work much better on a not perfectly clean base metal. Plus they have better mechanical properties and allow to use a slightly lower welding current than others, which reduce the thermal affected zone. However, not all welding machines can properly weld with those rods. You need a OCV at least 85 volts and to set correctly arc force parameter to get good results.