As some of you may recall, we got nearly all of the hard-water build-up off the grilles earlier this year. This is just a single summer's worth of the stuff. To the left is the spongy material that you put inside the grilles and through which water runs in order to cool things. Look at how much smoke got trapped by this thing!
The side grilles (both inside and out) were similarly afflicted.
I scrubbed and chipped the side grilles on Saturday and the rear grille on Sunday, and did the best I could to try and clean the cooler pads. (The later was so frustrating that I may in the future just replace them annually. It's too much work for too little accomplished.) There was still a lot of accumulated crud inside the cooler pan, so I bought another container of de-scaling solution and ran it through the cooler, dumped it out, and ran clean water through the cooler several times until most of the suds (from the descaling solution and from the attempts to clean the side pads) were gone.
As long as the hard water build up doesn't block the inlets for the water, this build up is mostly a cosmetic issue, so I did not try to get all of it off. I think I got about 75%. Some of it flaked off easily, but other parts are so heavily attached that even after a large dose of CLR solution (calcium-lime-rust), the only way it was going to come off was to take the paint with it.
Some paint has chipped off. After discussing it with Lisa, our plan it that once everything has dried out we are going to put the cooler away and put off grinding the rust off and repainting it again until next spring. This annual maintenance is a hassle, of course, but it's cheaper than letting things rust out entirely and having to buy an entire new cooler!
One other issue with this cleaning and maintenance is that swamp coolers appear to have lots of sharp edges and pointy bits on them. Despite wearing gloves while scrubbing the thing (because of the liberal use of CLR de-scaling solution), I managed to cut my hands in three separate places, all in the form of shallow scrapes that aren't serious, but hurt like blazes and have to be constantly re-cleaned and re-bandaged every time I wash my hands. They'll heal, of course, but it's annoying.