Jim Smith claims that people often don't know how to solder, applying heat at 350 degrees Celsius when the liquidus temperature of the solder should be the indication, and heat can set the service life back by many years, as well as reworking solder joints too much. Oxidation prevents a proper solder joint, even if it looks good, so he recommended to preapply separate flux. If it ain't broken, don't fix it is always an overarching principle, but you might not have the test instrument for electrolytic capacitors and they are strictly speaking not made for a service life of 30 years anyway.
Not sure if you have seen this that has an in-depth look at important details often glossed over in guides:
Health Hazards "The limited energy in capacitors (E = (1/2) C V²) restricts the duration of the shock, even if there are no circuit breakers to trip. The shock current will be limited by the body resistance, and the duration of the shock will be characterized by the time constant (τ = R C)...
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