Expert ROMSHI talks about lasers

What happens to a diode laser (808 nm) if you leave it in a garage with water inside the system?

What happens to a diode laser (808 nm) if you leave it in a garage with water inside the system?
(Realistic breakdown over time: 1 month → 1 year → 10–20 years → centuries)Assumed typical scenario:

  • The machine is turned off, water remained in the cooling system (not drained after the season).
  • Unheated garage: winter −10…−30 °C, summer +30…+45 °C, high humidity, dust, condensation.
  • Ordinary tap water (not distilled, no antifreeze/corrosion inhibitors).

After 1 month (autumn-winter, first frosts)

  • If temperature drops below 0 °C: Water freezes → ~9% expansion → rupture of copper/aluminum tubing, micro-cracks in the diode stack block, burst connecting hoses.
  • Probability: 80–95% in an unheated garage in Russia/Ukraine/Belarus/Kazakhstan.
  • What breaks first: the thinnest spots — copper microchannels in the diode stack, connecting fittings, plastic hoses.
  • Result: The laser is already dead for normal operation. Even after thawing — it leaks, overheats, bars burn out.

Here are real examples of what happens when water freezes and bursts copper tubing (common in cooling systems):

hackaday.com

After 1 year

  • Corrosion: Water + oxygen + temperature swings = intense electrochemical corrosion of copper and aluminum.
    Green/white patina (copper/aluminum oxides) appears, rust on steel parts.
  • Clogging: Salts, rust, algae/bacteria (especially with any light exposure) completely block microchannels → even after flushing, cooling works at only 20–40% capacity.
  • Electronics: Capacitors, control boards, contacts oxidize ("green plague") → power failures, sensor errors, short circuits.
  • Rubber/plastic: Seals and hoses harden, crack, lose tightness.
  • Result: Laser is 95% dead. Can be cannibalized for parts (stacks, lamps, drivers), but repair costs 70–90% of a new unit.

Real-world examples of green copper corrosion (verdigris/patina) from water exposure:

fischerplumbing.com

pugetsoundplumbing.com

Severe white oxidation on aluminum heatsinks after long-term water damage:

overclock.net

reddit.com

After 5–10 years

  • Complete degradation of cooling system: Microchannels fully blocked, copper dissolved into green mush.
  • Diode bars: Even untouched — moisture inside the stack → contact oxidation → most diodes burn out on first power-up attempt.
  • Plastics/composites: Yellowing, crumbling, extreme brittleness.
  • Metal: Aluminum radiators and copper tubes become porous like a sieve.
  • Result: Device suitable only for scrap metal + a few expensive parts (if you're lucky to salvage drivers/power supply).

After 50–100 years and beyond (centuries)

  • All metal parts in contact with water fully destroyed (copper turns to green powder, aluminum to white crumb).
  • Plastic/rubber components disintegrate into dust.
  • Electronics (boards, chips) oxidize beyond recognition.
  • Diode crystals might theoretically survive (if no voltage spikes), but without housing/contacts — useless.
  • Result: A handful of unrecognizable fragments remain, possibly a few intact lenses/sapphire windows (the most durable parts).

Quick timeline summary:

  • 1 month in winter → 90% chance of physical destruction from freezing
  • 1 year → corrosion + clogging → machine almost dead
  • 3–5 years → 100% beyond repair (except select expensive parts)
  • 10+ years → scrap metal + souvenir stacks (if lucky)
  • Centuries → dust + a few resistant lenses

Bottom line:
Never leave water in a diode laser's cooling system over winter in an unheated garage.
Drain → flush with distilled water + antifreeze → dry with air → store properly.
Otherwise, it's easier (and cheaper) to buy a new one than to resurrect a "drowned" machine after six months.If this exact situation happened to you — write what’s left of the unit, and we’ll try to figure out what (if anything) can be saved!