7 E. Deposition
Efficiency The
deposition efficiency is the relationship of the electrode used to the amount
of the weld metal deposited
expressed in percent, or: DE
= Weight of Weld Metal
Weight of Electrode Used.
For instance, if it takes 4 lbs. of
electrode to deposit 3
lbs. (1.4 kg) of weld metal, E = 3/4 = .75 or 75%. F. Gas
Flow Rate (Cubic Feet/Hour) For
GMAW with solid wires use a shielding gas flow rate of 25 to 30 cubic feet per
hour. For small diameter
flux cored electrodes (1/16” or 1.6 mm diameter and under) use 35 cubic feet
per hour. For large
diameter flux cored electrodes (5/64 and over) use 40-45 cubic feet per hour.
G. Gas Cost Per Cubic Foot
Gas cost per cubic foot will vary depending
on the type of shielding gas being used and your location.
3. Complete the calculations
in the “Proposed Method” and “Present Method” columns and
record the calculated
costs in the blanks on the far right, (5) & (6) of each column.
4. Add the calculated
cost and record the sums at the bottom, (7) & (8) of each column.
5. Subtract “Present
Method” cost (6) from “Proposed Method” cost (5) for each of the
sections titled “Labor &
Overhead”, “Electrode”, and “Gas”. Enter the differences
in the blanks indicated at right (5 minus 6). Negative
numbers should be enclosed in parenthesis “( )”.
6. In the “Total
Variable Cost/lb” section, subtract “Present Method” cost (8) from
“Proposed Method” cost (7).
Enter the difference in the blank indicated as “Total”. Negative
numbers should be enclosed in parenthesis
“( )”. A
(negative) number in “Total” represents the cost reduction you
will realize as a
dollar saving
per pound of weld metal deposited. 7. The
bottom section of the form will be useful if you must buy new equipment to use
the proposed product.
That part of the form is self-explanatory with the exception of the “DEPOSITION
FACTOR”. The deposition
factor is simply the deposition rate multiplied by the operating factor and is
already a part of the
calculation as shown at (9) in the labor and overhead formula for the proposed
method.