[ol' Stick Guy]

Try on your root with 6010 to weld in a keyhole with lower heat and dont be afraid to push it in a little, always keep a good leading angle on the transition into vertical.
When your ready for your second pass (you've got all that 6010 ****slag ground out) run your first E -7018 in nice and hot keping a slight weave level especially on the 6G (this way you avoid slag entrapment and under - cut)

 

[ol' Stick Guy]

Clean all your tacks really well (feathered out to a point) 1/16" land. About 62- 65 Amperes on 3/32" rod, assuming you are doing a 2" Sch. 80 Pipe keep a good lead angle on the E-6010 root keep a slight gap on the arc (about 1 1/2 times your gap on E-7018) I like to weld in a slight keyhole for E-6010
Stop @ the 9 o'clock and 3 o'clock positions respectively clean the crater of the weld out really good then do the verticals from 9 o'clock and 3 o'clock in order to minimize heat transfer.
Grind all the crud from E-6010 slag until you can see no dark spots at all at this point turn your machine up to between 82 - 87 Amperes and run a nicehot pass in on top of that E-6010 Sugar,Honey,Ice ,Tea

 

[ol' Stick Guy]

10" O.D and 1" wall you should be able to get away with a 1/8" E6010 root at least 3/32" gap and land
put a little pre-heat on the pipe just outside of the Heat Affected Zone to prevent excessive carbon precipitation (our Pipe Test procedure allows 250 deg. Fahrenheit) if you put too much heat or an oxidizing flame directly in your root opening you will BURN the metal and have a scaley inside root.
When you start filling up on a heavier walled pipe like that you want lots of heat (residual heat) to avoid distortional cracking, so keep your sides of the weave slightly longer in the corners (perhaps a
1-1/2 second count rather than a typical 1/2 second count. Also load up your grinder with a "soft"
1/4" stone and remove any dark spots you see.