All conditions
Condition
Heat exposure
The joint sees sustained or repeated heat — hot water, a microwave, a sun-baked surface.
What to do
Working with it
- Compare the joint's real temperature with the adhesive's max service temperature, not with the temperature it survives once.
- Ordinary super glue and PVA both soften well below boiling, which is why a mug handle glued with either lets go in a dishwasher.
- If the part sees a heat gun, an engine bay, or a stovetop, you need a specifically high-temperature epoxy — a general one is not enough.
Questions
Common questions
- Is application temperature the same as service temperature?
- No. Application temperature describes the conditions needed while the adhesive is being placed and cured; service temperature describes what the finished joint can tolerate later. Check both limits for the same product.
- Why does repeated heat matter more than one brief hot event?
- Repeated heating and cooling cycles soften the adhesive, move the materials by different amounts, and fatigue the glue-line edges. A joint that survives one event can still weaken gradually when the cycle becomes routine.
- Can sunlight make an outdoor glue joint hotter than the air?
- Yes. Dark surfaces, metal, glass, and enclosed spaces can become much hotter than the reported air temperature. Judge the adhesive against the temperature at the joint, not the weather forecast.
- Why are dishwasher and microwave repairs especially difficult?
- They combine heat with moisture, rapid temperature changes, and sometimes detergent or direct food exposure. Passing one of those conditions says little about whether the entire repaired object is safe and durable in the appliance.