Figure 38 illustrates welding at an angle.

The molten metal may be directed as to where it should go by the tip of the
welding flame, which has considerable force, but care must be taken not to
blow melted metal on to cooler surfaces which it cannot join. If, while
welding, a spot appears which does not unite with the weld, it may be
handled by heating all around it to a white heat and then immediately
welding the bad place.

[Illustration: Figure 38.--Welding at an Angle]

Never stop in the middle of a weld, as it is extremely difficult to
continue smoothly when resuming work.

_The Flame._--The welding flame must have exactly the right
proportions of each gas. If there is too much oxygen, the metal will be
burned or oxidized; the presence of too much acetylene carbonizes the
metal; that is to say, it adds carbon and makes the work harder. Just the
right mixture will neither burn nor carbonize and is said to be a "neutral"
flame. The neutral flame, if of the correct size for the work, reduces the
metal to a melted condition, not too fluid, and for a width about the same
as the thickness of the metal being welded.

When ready to light the torch, after attaching the right tip or head as
directed in accordance with the thickness of metal to be handled, it will
be necessary to regulate the pressure of gases to secure the neutral flame.

The oxygen will have a pressure of from 2 to 20 pounds, according to the
nozzle used. The acetylene will have much less. Even with the compressed
gas, the pressure should never exceed 10 pounds for the largest work, and