I stand corrected on the 6011. Live and learn, I like to use 7018 because the welds look better and it's sometimes refered to as a drag rod because you can stay very close to the metal and not worry too much about arc length. But I'm self taught.
This from the web:
Both 6010 & 6011 are Fast Freeze Rods, deep penetrating.
They both have a light flux which allows you to see the molten puddle clearly.
The weld is not as attractive, and is usually used as a first pass rod, which is then covered by another rod, such as 7018.
6011 is the easiest rod to use because of the stabilizers in the rod.
Arc Gap (the height of the tip of the rod off of the metal) is extremely important. Do not use a small Arc Gap. The small Arc Gap will not give the metal enough time to heat up.
7018
Shallower penetrating than 6010 or 6011
This is a low hydrogen rod with iron powder in the flux which prevents the weld from cracking.
One of the highest quality welding rod, and can handle higher stress.
The metal must be clean (no rust, dirt, oil, etc. on metal).
Iron powder higher metal deposit rate (used as a filler rod)
Has a heavier slag which allows the molten metal to solidify faster while slag is still molten.
The 7018 electrode is more sensitive to Arc Gap. Use a constant short arc gap with 7018.
Requires a higher amperage setting than 6011.
http://www.clovisusd.k12.ca.us/agcenter/arc_welding.htmStevem