Lincoln Electric POWER-ARC 4000 - Manual (Page 32)

B-17 OPERATION B-17
POWER-ARC 4000
Overhead Welding
Various techniques are used for overhead welding.
However, in the interest of simplicity for the inexperi-
enced welder, the following technique will probably
take care of his needs for overhead welding:
1. Use 1/8 ” (3.2mm) 90-105 A or 3/32 ” (2.5mm) 70 A
AWS 6011 electrode on AC.
2. Put the electrode in he holder so it sticks straight
out.
3. Hold the electrode at an angle approximately 30 °
off vertical, both seen from the side and seen from
end. (See drawing below.)
It is important to hold a VERY SHORT arc. (A long
arc will result in falling molten metal; a short arc will
make the metal stay.)
If necessary, and this is dictated by the appearance of
the molten puddle, a slight back and forth whipping
technique may be used to prevent
“ dripping ” .
Welding Sheet Metal
Welding sheet metal presents an additional problem-
burn through. Follow these simple rules:
1. Hold a very short arc. This, together with the prop-
er travel speed, will eliminate burn through.
2. Use 1/8 ” (3.2mm) or 3/32 ” (2.5mm) AWS 6011.
3. Use low amperage. 75 A for 1/8 ” (3.2mm) elec-
trode, 70 A for 3/32 ” (2.5mm) electrode.
4. Move rapidly enough to stay ahead of the molten
slag. A whipping technique may be used to further
minimize burn through.
5. If you have a choice, use lap joints rather than fil-
lets or butts; the double thickness effect of a lap
joint makes it much easier to weld without burning
through.
Hardfacing (To Reduce Wear)
There are several kinds of wear. The two most often
encountered are:
1. Metal to Ground Wear: Plowshares, bulldozer
blades, buckets, cultivator shares, and other metal
parts moving in the soil.
2. Metal to Metal Wear: Trunnions, shafts, rollers and
idlers, crane and mine car wheels, etc.
Each of these types of wear demands a different kind
of hardfacing electrode.
When applying the proper electrode, the service life of
the part will in most cases be more than double. For
instance, hardfacing of plowshares results in 3-5 times
more acreage plowed.
How to Hardface the Sharp Edge (Metal to Ground
Wear)
1. Grind the share, approximately one inch along the
edge, so the metal is bright and clean.
2. Place the share on an incline of approximately
20-30 ° . The easiest way to do this is to put one
end of the share on a brick. (See drawings) Most
users will want to hardface the underside of the
share, but some might find that the wear is on the
top side. The important thing is to hardface the
side that wears.
3. Use 1/8 ” (3.2mm) Wearshield at 80-100 A. Strike
the arc about one inch from the sharp edge.
Side View End View
30 °
30 °