Changed my mind about using a heat gun on plastic bumpers

I used to think a heat gun was the best way to reshape a warped plastic bumper, especially on a 2019 Honda Civic I worked on last month. I'd blast it for a minute or two until it was soft, then push it back into shape. But I kept seeing hairline cracks appear a few days later in the repair area. A guy at the supply house said I was overheating the plastic and weakening it. He told me to use a bucket of almost-boiling water instead, submerge the area for about 90 seconds. Tried it on a Toyota Corolla bumper this week and it worked perfectly with no stress marks. Anyone else find a better method for this kind of fix?

2 comments

2 Comments

lane.angela7d ago

The boiling water trick is good for simple warps, but it doesn't get deep enough for a real crease. A heat gun with a diffuser nozzle on low heat gives you more control over a specific spot. You just have to keep it moving and test the plastic with a gloved hand every few seconds. Once it's pliable but not shiny, you can mold it and it holds the shape without the cracks.

hollym827d ago

My old Warhammer sprue had a nasty bend. Used a hair dryer on low, held it about six inches away. Took a minute but it went back to perfect.