re-read the web page.
"see below (from
http://www.twi.co.uk/content/jk40.html go to the page for images):
Incomplete root
fusion or penetrationIncomplete root fusion is when the weld fails to fuse one side of the joint in the root. Incomplete root penetration occurs when both sides of the joint are unfused. Typical imperfections can arise in the following situations:[/i]
an excessively thick root face in a butt weld (Fig. 1a)
too small a root gap (Fig. 1b)
misplaced welds (Fig. 1c)
failure to remove sufficient metal in cutting back to sound metal in a double sided weld (Fig. 1d)
incomplete root fusion when using too low an arc energy (heat) input (Fig. 1e) too small a bevel angle,
too large an electrode in MMA welding (Fig 2)
Fig.
1 Causes of incomplete root fusion a) Excessively thick root face
b) Too small a root gap
c) Misplaced welds
d)
Power input too low
e) Arc (heat) input too low Notice that your points about bevel and joint fit up are also listed above. And so are mine about heat and electrode size.
