Cleaning parts using aqueous solutions are usually only one part of a much larger manufacturing process. When a problem arises in the process, technicians and engineers need to trace the source of the problem and determine the best solution.
Sometimes a problem will appear immediately after the step causing it. In those cases, troubleshooting can be simple and straightforward.
Other times, problems will only appear after several more processing steps. In these cases, tracing back the root causes can be difficult.
In this article, we outline 5 basic steps you can take to identify and resolve an issue with your aqueous cleaning system, and give you a list of common problems associated with water-based cleaners along with solutions for each.
5 Steps to Resolve an Aqueous NDT Cleaner Problem
- Identify: Identify the stage in the process where the problem first becomes apparent. Closely observe that stage to find out what makes the problem visible.
- Find the source: Starting with the identified stage where the problem becomes apparent, work backwards through the process and closely observe each stage to identify the source of the problem.
- Monitor: When the stage causing the problem is found, monitor that stage to find out if the problem is transient, if it is periodic or if it is inherent to the process.
- Dig deeper:
If the problem is transient or temporary, identify whether any materials or conditions have changed. Sometimes a simple change in material can introduce unforeseen problems.
If the problem is periodic or sporadic, observe the environment and nearby process stages. Sometimes seemingly unrelated operations can influence each other to create a problem.
If the problem appears to be inherent in the process stage, collect as much information as possible. Evaluate whether the problem can be eliminated by changing the stage where the problem originates, or by changing the stage where the problem becomes apparent. Determine whether subsequent process stages would be affected.
5. Take Action : Based on the information you have, implement the best solution to the problem.
Common Problems with Aqueous Cleaning
If you have concerns or troubles with your process that are not covered in this list, please let us know so our experts can help you find the right solution to your cleaning issues.
Part is not clean (general)
Possible Causes
Solutions
Cleaner concentration is too low
Check cleaner concentration and adjust if necessary
Temperature is too low
Check temperature controller and adjust if necessary
Parts are not cleaned for long enough
Increase the time that the part is processed
Cleaning solution is loaded with too much soil
Check soil levels. If necessary, dump cleaning solution and clean out reservoir to remove soil sediment. Refill with fresh cleaning solution
Parts are not rinsed enough
Increase rinsing time. Increase flow of rinse water. Check rinse water for contamination.
Cleaner solution is not aggressive enough
Switch to a higher pH, higher alkalinity cleaner, let us help you select the right Daraclean cleaner
Part is not clean (hand scrubbing)
Possible Causes
Solutions
Parts are not scrubbed enough
Increase scrubbing action on part
Part is not clean (soak tank, agitated tank, ultrasonic tank)
Possible Causes
Solutions
Dirt is not being lifted off surface because ultrasonic power is too low
Adjust ultrasonic power setting
Large particles not removed because ultrasonic frequency is too high
Adjust ultrasonic frequency setting
Small particles not removed because ultrasonic frequency is too low
Adjust ultrasonic frequency setting
Too many parts loaded in bath at one time
Decrease number of parts processed at one time
Part is not clean (spray washing)
Possible Causes
Solutions
Too many parts being processed at one time
Decrease number of parts processed at one time to allow more space
Parts are arranged so that spray is inconsistent
Rearrange parts in basket
Part surfaces are dark after cleaning
Possible Causes
Solutions
Cleaner concentration is too high
Check bath concentration and dilute if necessary
Bath temperature is too high
Check bath temperature controller and adjust if necessary
Metal surface is being attacked by aggressive chemistry
Switch to lower pH, l ower alkalinity cleaner solution
Switch to a solution with more corrosion inhibitors
Let us help you select the right Daraclean cleaner
Parts have a rainbow pattern similar to heat burn
Possible Causes
Solutions
Bath temperature is too high
Check bath temperature controller and adjust if necessary
Dryer temperature is too high
Check dryer temperature controller and adjust if necessary
Part surfaces show pitting, but part surface is otherwise clean
Possible Causes
Solutions
Metal surface is being attacked by aggressive chemistry
Switch to lower pH, lower alkalinity cleaner solution
Switch to cleaner solution containing more corrosion inhibitors
Add low-concentration corrosion inhibitor to rinse water
Use a protective coat of machine oil for long-term parts storage
Let us help you select the right Daraclean cleaner
Part surfaces have starburst pattern
Possible Causes
Solutions
Part surface being damaged by ultrasonics
Decrease ultrasonic power
Increase ultrasonic frequency
Cleaning solution turns yellow or brown
Possible Causes
Solutions
Bath temperature too high
Check bath temperature controller and adjust as necessary
Cleaner concentration too high
Check cleaner concentration
Cleaning solution oxidized over time
Ambient air can cause certain cleaner formulations to oxidize and darken over time. This does not affect the usefulness or cleaning ability of the solution.
Cleaning solution loaded with too much emulsified oil
Check soil levels. If necessary, dump cleaning solution and clean out reservoir to remove soil sediment. Refill with fresh cleaning solution.
A film of oil develops on top of the cleaning solution
Possible Causes
Solutions
Cleaner concentration too low
Check cleaner concentration and adjust as necessary
Bath temperature too low
Check bath temperature controller and adjust as necessary
Oil-phase de-foaming agent added
If an oil-based de-foaming agent is in use, the film of oil on top of the solution is there to prevent the formation of foam
Oil loading in cleaner tank too high
Check soil levels. If necessary, dump cleaning solution and clean out reservoir to remove soil sediment. Refill with fresh cleaning solution
Cleaner chemistry not compatible with soils being cleaned
Switch to a different cleaner that is chemically compatible with the base material and soils being cleaned.
Also read, 5-Point Guide to Understanding Aqueous NDT Cleaning
Excessive foam
Possible Causes
Solutions
Too much agitation
Decrease agitation until foaming stops
Spray pressure and volume too high
Check pressure and flow regulators and adjust if necessary
Recirculation pump cavitating
Check condition of pump and check for flow blockage
Cleaner concentration too high
Check cleaner concentration and adjust as necessary
Bath temperature too low
Check bath temperature controller and adjust as necessary
Cleaner de-foaming agents used up
Replenish de-foaming agents
Foaming soil or additive introduced to bath
If soil is naturally foaming, a different cleaner formulation may be required, or additional de-foaming agents may need to be used, let us help you select the right Daraclean cleanerhttps://www.magnaflux.com/Contact-Us.htm
Parts have a film of oil when removed from the cleaning solution
Possible Causes
Solutions
Parts not completely cleaned
See above recommendations for Part is not clean
Oil loading of cleaner bath too high
Check soil levels. If necessary, dump cleaning solution and clean out reservoir to remove soil sediment. Refill with fresh cleaning solution
Oil contamination of rinse water
Check rinse water to make sure only clean water is used for parts rinsing
Parts have excessive grease or heavy oils before cleaning
Add pre-cleaning step to remove excessive grease and heavy oil from parts
Cleaner chemistry not compatible with soils being cleaned
Switch to a different cleaner that is chemically compatible with the base material and soils being cleaned, let us help you select the right Daraclean cleaner
Parts have a white film or powdery residue
Possible Causes
Solutions
Parts not sufficiently rinsed after cleaning
Check rinse water to make sure only clean water is used for rinsing
Increase rinsing time or add second rinse stage
Increase rinse water flow or agitation in rinse tank.
Hard water scale forming on parts
Install water conditioners on the processing line
Switch to a different cleaner that has better hard water tolerance, let us help you select the right Daraclean cleaner
Silicates precipitating on parts
Switch to a different cleaner that does not use silicates, let us help you select the right Daraclean cleaner
Excessive scale buildup on tank fixtures or heater
Possible Causes
Solutions
Hard water scale
Install water conditioners on the processing line
Switch to a different cleaner that has better hard water tolerance, let us help you select the right Daraclean cleaner
Silicates precipitating on parts
Increase maintenance routines to clean scale off more frequently
Switch to a different cleaner that does not use silicates, let us help you select the right Daraclean cleaner
Part surfaces appear grainy after cleaning
Possible Causes
Solutions
Part is being etched by galvanic action between dissimilar metals
Verify that all equipment and cleaning tanks are properly grounded. Verify that part baskets or fixturing are properly grounded
Part is being attacked by aggressive cleaner chemistry
Switch to a cleaner that is compatible with the base metal of the parts, let us help you select the right Daraclean cleaner
Color of alloy changes after cleaning
Possible Causes
Solutions
Part is being anodized by galvanic action between dissimilar metals
Verify that all equipment and cleaning tanks are properly grounded. Verify that part baskets or fixturing are properly grounded
Part is being attacked by aggressive cleaner chemistry
Switch to a cleaner that is compatible with the base metal of the parts, let us help you select the right Daraclean cleaner
Cleaner tank begins to rust at comers
Possible Causes
Solutions
Galvanic action is corroding metal of cleaner tank
Verify that all equipment and cleaning tanks are properly grounded
Let us help you determine the root cause and solution to advanced cleaning problems
Cleaner system begins to leak
Possible Causes
Solutions
Galvanic action is corroding metal of cleaner tank
Verify that all equipment and cleaning tanks are properly grounded
Rubber gaskets and seals being attacked by oils removed from parts
Verify all seals used in cleaning equipment are compatible with the oils and solvents being removed from parts at the temperatures being used
Let us help you determine the root cause and solution to advanced cleaning problems
We are ready to provide additional assistance with troubleshooting of cleaning processes, help with selecting the best cleaning solution for a part or soil, or to answer general questions about industrial parts cleaning.
Source: https://www.magnaflux.com/Magnaflux/Blog/Troubleshoot-NDT-Cleaners
Blog By: David Geis, Product Manager
