I have main boards, power supplies, and so on as spare parts. But sometimes they spend several years in my workshop waiting for a customer. When I find the right customer, several times the boards were damaged, mostly because of corrosion.
How could I save the boards, obviously without damaging them (anticorrosion, silicon, and lacquer)?
For long term storage, what I usually do is put the item in an anti-static plastic bag, put some desiccant packets if available, then seal it (video) using an impulse sealer. This method has yet to fail me.
The plastic, desiccant, and impulse sealer can be acquired for cheap, at least in the Philippines.
When comparing environments care must be made with comparisons.
I am in New Zealand. In my city corrosion rates are high. Elsewhere in the country corrosion rates are much lower. While temperatures and rainfall can be similar or different the main factor is distance from the sea (!).
Note: Maracaibo climate is hot all year round (about 25C) and moderately wet in winter. It is on the ocean. Corrosive salt in the air is probably a major problem (as jsotola says). It is NOTHING like Las Vegas which is far from the sea, gets hotter and much colder and is very dry. ie it is always important to look at actual parameters
Storage in an area fed with filtered contamination free and low humidity air can help.
A very low airflow via a suitable filter is OK as long as overall you maintain even a slight "positive pressure" so the outside air is eliminated.
A good quality conformal coating will provide an excellent solution, but car must be taken not to coat connectors and in some cases "wicking" into some sockets and similar can occur.
As an example only, Dowsil 1-2577 is excellent but may not be readily available to you. This is expensive in small volumes, gets MUCH cheaper in moderate amounts and covers a large area - a film 0.1mm thick is adequate and can be applied by dipping brushing or spraying.
A cheap conformal coating which MAY be adequate - if using it you should test it on some target boards in your environment - is "polyurethane spray" / varnish / laquer. This is not as effective as eg 1-2577 but is very low cost and widely available. Polyurethanes usually set by absorbing moisture from the air - it would probably be wise to ensure that the moisture that is absorbed while drying is salt fee. As with any conformal coating, be aware of coating contacts and possible issues with "wicking" on connectors and sockets.
Anticorrosion vapour emitting products have been mentioned. These can work well but have major problems if used with incompatible materials.
i.e., Anti corrosion vapor emitters MAY be suitable BUT always ask the manufacturer - whether re Zerust or similar products.
From the Wikipedia article on Volatile Corrosion Inhibitor:
I think you can stick them in an airtight box with rust inhibiting vapour block.
https://www.zerust.com/products/vci-emitters-diffusers/
Just make sure your box isn't a plastic box ridden with static charge.
Former service manager here. If your job is protecting these repair parts, then you don't get to shrug off your local climate being what it is. It is your job to maintain climate control in the storeroom 24x7, both temperature and humidity. If you can't do that, then you need to date stock and redline it past a certain number of months.
Mind you, you don't have to clmate control a whole room or building. Just the stock. If you can get it done with an old refrigerator rigged to keep things at 25C, with an incandescent bulb to heat when ambient temperature falls below 15C (and gosh, most refrigerators have a light bulb socket already in them), and manual dessicant packs to remove humidity... good enough.
Good way to store welding rods, too.
Intentionally having the refrigeration coils and the light bulb fight each other is a good way to dry out the air. You wouldn't want to do that continuously, just turn the light bulb on anytime the humidity is too high and let the thermostat turn on the compressor.
The gold standard for long term storage of sensitive electronics is dry nitrogen. But that's probably not cost effective for what you want to do.
I would recommend a sealed off storage area with conditioned air into it - either a separate AC unit or a dehumidifier. There's a sweet spot for electronics in so far as relative humidity goes. You want the air dry enough so that you're well away for the dew point temperature (where moisture condensed out of the air), but moist enough so that static buildup (ESD) is not a problem. I think that range is something like 40% to 70% RH (30%-60%?), but don't quote me on those exact numbers.
I repair Apple devices and I use Anti-Static bags stored in plastic bins. I often throw in some desiccant for good measure.
https://www.uline.com/BL_2368/Static-Shielding-Tubing
https://www.uline.com/BL_7852/Uline-Anti-Static-Reclosable-Bags
