Trial #4
To evaluate successful cleaners on fourth contaminant
The four successful cleaners from the previous trial were again diluted to 5% using DI water in 600 ml beakers and placed in a Crest 40 kHz ultrasonic tank model 4Ht 1014-6. Solutions were heated to 130 F. Twelve preweighed coupons were coated with Hubbard Hall Inc, Metal Guard 270 and reweighed. Three coupons were immersed into each solution and cleaned for five minutes. The coupons were rinsed in tap water at 120 F for 30 seconds and dried using a Master Appliance Corp, Hot-air gun model HG-301A at 500 F for 1 minute. Final clean" weights were recorded and efficiencies were calculated.
All four solutions removed over 99% of the Metal Guard 270 from the coupons in less than one minute of ultrasonic cleaning. This contaminant made the cleaners cloudy, suggesting difficulty in treating the solutions. The following table lists the efficiencies for each coupon cleaned.
| Cleaner
|
Coupon 1
|
Coupon 2
|
Coupon 3
|
Average
|
Std Dev
|
| Oakite
|
100.00
|
99.81
|
99.92
|
99.910
|
0.10
|
| Daraclean
|
100.25
|
99.89
|
100.16
|
100.10
|
0.19
|
| Green Stuff
|
100.00
|
99.75
|
100.00
|
99.92
|
0.14
|
| Beyond
|
99.53
|
99.39
|
99.33
|
99.42
|
0.10
|
The four cleaners were effective in removing the Metal Guard.
No relation