The production run is done and now the mold won’t be used any time in the near future. Time to prepare it for the rack.
As the mold is cooling, apply rust preventive to the mold cavity, the plates and mold base to help prevent condensation from causing rust and oxidation. This is a “dirty” step since the hot mold will likely cause the oils in a rust preventive to liquefy and run. It still protects the mold until it is cool enough to pull and take it to the tool room to break it down.
Now that you are in the tool room, break down the entire mold system to look for gas buildup, color stains, water stains, resinous deposits and any other contamination that might have built up on the mold unit during the production run. Use a solvent-based degreaser and/or mold polish to remove these contaminants and give you clean mold that is immediately ready to make parts when it comes out of storage.
Now protect the mold with a long-term rust preventive that is rated for the length of time you need protection while the mold is in storage. The American Society for Testing and Materials (ASTM) testing method for rust preventives designates long-term rust preventive as being effective for up to 5 years of indoor storage. If you are storing a mold longer than 6 months, we recommend that the entire mold block (cavity as well as mold base) be protected with an oil-based rust preventive.
It is also best practice to crack open and inspect any mold stored for longer than 12 months, looking for any signs of corrosion. You should reapply rust preventive product following these inspections to ensure all critical surfaces are protected.
Has your mold been running PVC or any other gas-emitting resin? Be sure to use a rust preventive with protection against not only corrosion due to moisture, but also oxidation caused by the presence of the acidic vapors released by these resins. To ensure your mold has continuous protection you should reapply this rust preventive every 30 days to ensure that the acids present in the area around the mold continue to be neutralized.