Stainless steel coupons were chosen for this testing. A 2 in by 2 in section of each coupon was scratched with a sharp metal tool in order to scratch away at the protective coating of the surface. Coupons were then weighed and had their initial weights recorded. White vinegar was poured on the scratched sections of the coupons and were allowed to air dry in order to start the process of oxidation. After drying, a mixture of white vinegar, hydrogen peroxide, and table salt was poured on the scratched sections of the coupons and were left to air dry. Once dried, it was evident that flash rust had formed on the surface of each coupon. The dirty weights of the coupons were then recorded. The visual rankings of dirtiness were also recorded according to the visual observation criteria listed below. Half of the coupons were cleaned immediately using the Picklex Degreaser by method of heated immersion at 125 F for 90 seconds. The other half of the coupons were left to sit for one week in order for the rust to age. After one week, these coupons were cleaned using the Picklex 20 spray (ambient temp) by spraying the product onto their surface and allowing a 90 second contact time before wiping the surface with a paper towel (single wipe). Each coupon was then rinsed with cold tap water for 60 seconds. After cleaning steps, the coupons were then left to air dry before their clean weights were recorded, and clean visual rankings were made.
Visual Ranking criteria:
1= 100% soil removed (most clean)
2= 75% soil removed
3= 50% soil removed
4= 25% soil removed
5= 0% soil removed (most dirty)
Both products were highly effective in removing flash rust from stainless steel, although both products were observed to have a slightly higher efficacy in removing unaged flash rust as opposed to aged flash rust. This difference is very small and was only observed using gravimetric analysis (not visually observable).