Corrosion prevention for long-term storage
Buyers are pressured to get the highest quality part for lowest prices in today’s market. As the manufacture, we are then forced to balance high quality and lower piece prices while still generating a profit for the company. This marriage tends to leave the supplier with large quantities of product that can tarnish, corrode, or rust for an extended amount of time.
High quality is achieved when using specialty / high-end tooling, proper cutting oils, and tuned set-ups in capable machines. These factors raise piece prices dramatically. But if spread out over large quantities, high quality can be obtained at lower prices. We need to look at our processes and storage conditions to ensure parts will look like they just came off a machine, months after being put into storage containers.
One avenue we looked into was corrosion prevention. We gathered a range of materials we use and set-up various scenarios to compare the following:
- Our current processes- A base line to compare the new processes too.
- Best/ worst case scenarios- Test the new product’s limits and see it’s capabilities under extreme conditions.
- Realistic/ cost effectiveness- Determine if the cost of updating processes is worth the reward of increased part longevity for our company and customers.
We started our study on January 22, 2016 and over the coming months, we will monitor and post updates about each scenario of our part preservation experiment.
Both the 1215 and 41L40 Heat Treated steel parts are rust free under our current methods and with the new corrosion prevention material. The parts that were cleaned in pure Stanisol, our current cleaning solvent, have spots that appear darker and might be the start of rusting. The new corrosion prevention liquid is still wet on the parts while the current methods are dry.
Both the 1215 and the 41L40 Heat Treated steel parts have no change. The dark spots previously suspected of becoming rust, have not rusted after an additional three months.
Our current process of cleaning brass, copper, stainless steel, and aluminum in Stanisol, has not tarnished the parts. Parts that require no residue are washed in Oil Eater. The copper and brass parts showed some slight darkening with this process. The tin plated brass part straight from the plater has some spots of discoloration and the surface in direct contact with the box had more discoloration. Zinc Plating was unchanged.
After another 3 months, our brass, copper, stainless steel, aluminum, and zinc plated parts have not changed color. The tin plated brass discoloration previously observed, has not grown larger.
The 1215 and 41L40 Heat Treated parts were cleaned in Oil Eater to simulate the harshest conditions the new corrosion prevention paper might run into. Th 1215 part rusted on the ID surfaces. and showed spots of rust on the OD surfaces. The 41L40 Heat Treated part was showing minor build up on the threads, possibly due to the heat treat process.
The 1215 and 41L40 Heat Treated parts cleaned in Stanisol and wrapped showed no signs of rusting on ID or OD surfaces.
The copper parts washed in Stanisol and wrapped in the corrosion prevention paper showed signs of discoloration. All other parts were unchanged.
Silver plated parts in the corrosion prevention bag and paper showed spots of discoloration. Looks like a splatter that might be due to the platting process.
Bag 1– 1215 part cleaned in Oil Eater has rust on the ID. All other parts are unchanged.
Bag 2– Copper and brass parts cleaned in Stanisol in the bag show signs of discolorations. All other parts are unchanged.
The boxes still look intact. The tape, when picked at, separated the paper layer from the string and adhesive layer. The glue holding the box together started to separate when pulled on as well as it was tacky to touch. Our Poly bags shrank and the liquid was able to get out the top zipper, possibly due to being laid on its side.