25 FIG.
11 - Effect of Root Face Dimension b.
Unsatisfactory Root Face. Base Metal has Fused
Through Bottom 2.
Machined Edge Preparation may be done with gate shears, planers, lathes, boring
mills, shapers, etc. depending
upon the availability of equipment, type of cut required, etc. If gate shears
are used for edge preparation,
any heavy rust must be removed before the shearing operation to prevent it from
becoming embedded
in the edge. Rust which has been embedded through shearing cannot be removed by
wire- brushing,
but should be machined or ground off before welding. If cutting oils or greases
are used in machined
edge preparation, they should be removed with a degreaser that will leave no residue
upon evaporation.
(See Methods of Cleaning, below.) 3.
Manual Chipping and Grinding - are sometimes used in edge preparation instead
of flame cutting or machining.
The accuracy of edge preparation is dependent upon the operator’s skill.
4. Forging, Rolling and Casting - sometimes
form the edges desired for welding forged, rolled or cast parts.
