🔥 Thermal burns
caution
Where you meet it: Exhaust systems and O2 sensors · turbochargers · engine blocks · recently-run equipment · preheat plates
What you need to know
- Exhaust components reach 800 °C and stay dangerous for a long time after shutdown. Work on a stone-cold engine — it also stops O2 sensor threads galling.
- Preheat plates and hot air guns cause the most common shop injuries in this hobby. Set the tool down in a known place, every time.
- Aluminium cylinder heads strip their threads when hot — another reason to wait.
The rule: Don't rush a hot engine. Nothing here is worth a hand.
Components this applies to
Laboratory Platinum Ware
Pt ~454 g/lb — it is solid metalAu 5% in Pt-5%Au XRF fusion cruciblesBase Rh 5–10% in Pt-Rh crucibles
S
Backup batteries & Dallas RTC modules ☠
Cu ~40 g/lbAu <0.1 g/lb
C
Laser Printer Boards, Fusers & Toner Chips
Au 0.01–0.04 g per formatter board ≈ 0.045 g/lbAu 0.0005–0.002 g per toner CRUM chip ≈ 0.3–0.8 g/lb of chipsBase Fuser: no precious metal whatsoever
D
MAF, MAP, knock, crank & cam sensors
Pt 0.5–2 mg per hot-wire MAFAu 0.003–0.010 g per MAF boardAg 10–40 mg thick-film paste on MAP hybridsNd magnets in Hall-type crank/cam sensors
D
Oxygen / lambda sensors
Pt 13 mg per sensor (≈0.05 g/lb)Cu 8–20 g in the leadBase steel body
D
Spark plugs
Pt 1–8 mg per plugBase iridium 0.6–3 mg on Ir plugs
D
Thermal Printheads
Au 0.002–0.02 g per head ≈ 0.06 g/lbBase Ru as RuO2 glazeBase alumina substrate + Al heatsink bar
D