Most parts-washer sumps are run by habit. The cleaner concentrate goes in at whatever percentage the last drum label said, the heater is set where it was when the machine arrived, and the bath gets dumped when the parts start coming out oily or the operator cannot stand the smell any more. Somewhere between those two events the cleaner has stopped doing its job, and the parts on the rack behind the washer are already flash rusting. The cost is not the cleaner. It is the sump changes, the rework, and the assemblies that get built with a film of oil still on the mating faces.
Three Cortec case histories, one recent and two older, show what happens when you treat the wash as a process instead of a chore: an alkaline VpCI cleaner at a tenth of the incumbent’s concentration cleaned better and tripled sump life, a three-stage wash stopped in-plant rust at an Indiana parts plant, and a UK casting shop turned two top-loading washers into a de-rust and preservation line.
A gearbox parts washer at 0.5 percent instead of 5 percent
Cortec Case History #676 (2019) describes an excavator plant that washed gearbox components before assembly in a heated spray washer. The incumbent cleaner ran at 5 to 6 percent concentration and 65 to 70 °C (149 to 158 °F). The sump lasted 30 to 45 days, and even at that dose the parts came out with oil still on them, which the assembly line refused to accept. The plant wanted better cleaning, some short-term rust protection, and a lower running cost, but did not want to rebuild the process to get it.
The change was one product. VpCI-414 went into the same washer at 0.5 percent, and the temperature stayed at 65 to 70 °C. Nothing else moved: same machine, same cycle, same operators.
| Incumbent cleaner | VpCI-414 | |
|---|---|---|
| Concentration | 5 to 6 percent | 0.5 percent |
| Bath temperature | 65 to 70 °C | 65 to 70 °C |
| Sump life | 30 to 45 days | 90 days |
| Oil left on parts | Yes | None reported |
The plant reported cleaner parts, no oil carryover, a 90-day sump, and a lower cost per load. It moved VpCI-414 onto regular order and planned to specify it for a second washer. Two things are worth noting. First, 0.5 percent is well below the 5 to 20 percent range on the VpCI-414 data sheet; the plant got there by trial, with heat and spray impingement doing part of the work. Second, VpCI-414 leaves a flash-rust inhibiting film behind, which is why the parts could sit between wash and assembly without the usual staining.
The three-stage recipe that stopped in-plant rust
Cortec Case History #095 (1998) is older, but the recipe is still the one we hand to customers with a multi-stage washer. An Indiana automotive parts plant, a division of a Big Three automaker, was running a two-cleaner wash and still losing parts to corrosion before they left the building. Cortec’s products were approved into a three-stage washer:
- Stage one: 5 percent VpCI-414 with 0.4 percent S-16 defoamer, because VpCI-414 foams in a spray cabinet.
- Stage two: plain water rinse.
- Stage three: 10 percent VpCI-377, a water-based rust preventative that dries to a thin, paint-over film.
Trials three months before the switch showed no corrosion. The plant also cited the environmental profile of the water-based products as part of the decision. At 10 percent, VpCI-377 is rated for up to two years of indoor protection, so the parts left stage three ready for storage, not just ready for the next operation.
Two washers turned into a de-rust and preservation line
Cortec Case History #520 (2016) shows the same thinking applied to salvage. A UK castings manufacturer had hundreds of machined, washed and stored parts rust badly before shipment. Rather than buy new equipment, it built a five-stage line around the two top-loading washers it already owned:
- Spray VpCI-422 rust remover in the first washer at ambient temperature.
- Neutralize in the second washer with a VpCI alkaline cleaner at 10 percent and 70 °C. (The case used VpCI-419; VpCI-414 at 5 to 10 percent is the neutralizing step Cortec specifies after 422 today.)
- Dip in BioCorr and dry on a purpose-built table, for up to 24 months of protection.
- Repack on pallets in VpCI packaging with desiccant.
- Write the procedure down and train the operators.
The shop reported no further rusty parts in storage or transit, and the group rolled the process out to its other sites. The lesson for a Midwest job shop is that a de-rust line is two tanks and a drying table, not a capital project.
How to do this in your plant
- Know what is in the sump today. Titrate the current bath and write down the concentration, temperature and dump interval. Our VpCI concentration testing guide covers the titration kits and refractometer method for Cortec cleaners.
- Pick the cleaner by washer type. VpCI-414 foams, so it belongs in immersion and soak tanks, or in a spray cabinet with a defoamer as in #095. For a Build-All or Magido spray cabinet, we usually start with a low-foam cleaner from the same family and keep VpCI-414 for the dip tank.
- Start at 5 percent and work down, not up. Hold the heat at 60 to 70 °C, run a week of production, and cut the dose until cleaning falls off. Most shops settle far below where the old drum label had them.
- Add a rust-preventative stage if parts wait more than a few days. A final dip or spray of VpCI-377 at 2 to 5 percent gives about a year indoors; 10 percent gives two. BioCorr is the ready-to-use alternative when you want a dry, near-invisible film and no dilution step.
- If the parts are already rusty, put a VpCI-422 station in front of the washer. Soak, rinse, then run the normal wash cycle; the cleaner neutralizes the 422 and leaves the flash-rust film behind.
- Package what leaves the building in VpCI-126 bags so nobody at the receiving end has to degrease it.
Which Cortec products
- VpCI-414, 5-gallon pail: the alkaline cleaner in the case; immersion tanks, soak stations, and spray washers with defoamer. Also strips Cortec temporary coatings at 60 percent.
- VpCI-414, 55-gallon drum: for a production washer that gets topped up weekly.
- VpCI-377: final-stage rust preventative in a washer or dip tank; one to two years indoors depending on concentration.
- BioCorr: ready-to-use, biobased dip or spray after washing; up to two years indoors, dry film, rinses off.
- VpCI-422: biobased rust remover for a de-rust station ahead of the washer; not for aluminum.
We stock VpCI-414, VpCI-377, BioCorr and VpCI-422 in Elmhurst, Illinois, alongside the Build-All and Magido washers they run in. If you want to find out what concentration your washer actually needs, contact us for a sample pail and a titration kit, or ask us to set up a trial on one of our demo cabinets.
Sources: Cortec Case History #676 (2019), Cortec Case History #095 (1998), Cortec Case History #520 (2016); Cortec product data sheets for VpCI-414, VpCI-377, BioCorr and VpCI-422.