Spatter in welding is very common, we see it everywhere. We assume that it is something we have to learn to live with and cannot get rid of. Or, if we can get rid of it, we think that it is more trouble than what it’s worth. If you want to know the causes for welding spatter check out the post on 7 Causes of Spatter and How to Eliminate It.
The reason why there doesn’t seem to be much effort put into eliminating spatter at a vast number of manufacturing facilities is that most people don’t know the true cost of it. We know spatter looks bad, we know it requires time to grind it off, we may even know that it increases the amount of welding consumables needed for a job. But ask yourself, have I ever sat down to evaluate what spatter is costing me?
The example below is simply meant to get you thinking about what spatter is costing you. The numbers can be changed as you please, but be mindful of the percent reduction in total cost. You may have a special situation where this does not apply, but it would be more the exception rather than the norm.
Scenario: ACME Welding uses the GMAW process with C25 shielding gas. They use the short arc and globular modes of metal transfer which generate significant spatter. They cannot have spatter on their finished assemblies since they will be painted, and paint makes spatter stick out like a sore thumb. They manufacture the same part day in and day out. This example looks at the cost during a 3-week period, before and a 3-week period after changes were made.
Material and Labor Costs
740# of .045 ER70S-6 Wire ($1,295)
32 Grinding Wheels ($224)
2-gal Anti-spatter ($68)
C25 Shielding Gas ($277)
Labor = 15days x 7welder x8hours = 840 hours @ $45/hr (labor & overhead) = $37,800
Total Cost: $39,664
After switching gas to 90%Ar/10%CO2 and adjusting welding procedures spatter is reduced by 85%. This reduces grinding wheel usage, anti-spatter usage and even amount of wire needed. The wire is reduced because spatter is lost filler metal. About 40# on this job. The gas is more expensive by about 10%. Although in this case better procedures also improved deposition rates, for the sake of the example they were kept the same (7.2#/hr).
Spatter was reduced following the guidelines in 7 Causes of Spatter and How To Eliminate It.
700# of .045 ER70S-6 Wire ($1,225)
32 Grinding Wheels ($90) – not all grinding was for spatter so reduction is not as much percentage-wise.
2-gal Anti-spatter ($68) – shop practice is to use it, so it is still being used although it could have been limited to specific applications.
90/10 Shielding Gas ($304) – upgrade to a more expensive shielding gas that allows for spray transfer.
Labor = 11.8days x 7welder x8hours = ~660 hours @ $45/hr (labor & overhead) = $29,700
New Total: $31,387
This change reduced the cost of this job by $8,277 or 21%. We continually forget about the cost of labor and focus to much on the cost of raw materials. Most companies keep using 100% CO2 or even C25 because it is cheaper than a 90/10 gas shielding mix. A simple switch to a better gas and improving your welding procedures can lead to significant savings.
This example is real. But feel free to plug your own numbers in and see how it applies to you. Sometimes this type of change may require better or bigger (or both) welding power sources. But remember that the savings go on forever because you are reducing spatter and the cost associated from removing it.
Have you undertaken a project to reduce welding spatter? What are your thought? Did you see significant savings?