Bumper dimples

[BMS 4EVER]

I know a bunch of you have em and I know a bunch of you got rid of em. How did you do it? I've seen the dry ice method and the heat gun method but I heard doing these things can severely damage the paint and it will begin to flake off after just a year. Can anyone help?

[jnshk]

I did the heat gun method. No damage to the paint and it's been about two years since then.

To do this right, you need to remove the bumper cover from the car. Heat it from the back side of the bumper with the heat gun on a relatively high setting, occasionally adding heat to the front side for a moment and then again to the back side. Try to do a wide bit of area around the dimple itself and not just centered on a small spot. This will help you keep things smooth and avoid hot-spot stretching and making the dimples worse. As the plastic heats up enough and begins to soften you can apply some pressure and push the dimples back out. Sometimes you will have to hold some pressure against the dimples as it cools in order to set it back into the proper position. Just stop applying heat when it gets soft and then apply more heat again when it starts to set up. I used welding gloves to work with the hot plastic bumper cover, but you might be able to get by with some mechanic's gloves.

If you heat it up enough to damage the paint, you've done it wrong.

[itzzspencer]

wait, so you used the heat gun + dried ice?

[jnshk]

No dry ice at all.

If it's like mine where the bumper is extremely wavy and has been "set" by many heat cycles in hot Texas sun, dry ice won't do a lick of good. The plastic is already deformed and the "memory" of the original shape is long gone.

I'm also not sure that the hold-and-cold treatment is very effective on plastic. I think it is primarily intended for use on thin sheet metal body panels where there is a higher rate of heat transfer.

[WiLdWiLL]

I used a heat gun, removed my bumper, aimed the heat gun inside the bumper and pushed out the dimple as it got hotter, looks a lot better.

[BMS 4EVER]

What did you use to protect your hands from the heat? And did it stick because of the heat at all?

[jnshk]

I used welding gloves, but I think that even a pair of mechanix gloves or thick jersey gloves would be sufficient. You're getting the plastic pretty darn hot, but not insanely hot.

You want to soften the plastic so that you can firmly push it back out from the backside and hold it in position to let it "set" in the proper shape again as it cools. You don't want to heat it so much that it starts getting droopy and flimsy.

[jacksmiata]

Oh I need to try this heat gun method! Thanks for the tip!

[moerdogg]

I too used the heat gun method with the bumper off the car. Did it inside during the winter, so it looked good, but once I got it outside it wasn't perfect. Someday I'll get motivated and eliminate the dimples completely.

Before:
https://lh3.googleusercontent.com/-d_l7zwEkJhA/ShdbyxkQc4I/AAAAAAAAAuk/mgkfkCDZato/s1024/DSCN0892.jpg

After:
https://lh5.googleusercontent.com/-44ERMhuky2Y/T1T-OZLHgGI/AAAAAAAACIk/L1nDmu2uJYY/s561/DSCN1254.jpg

[WASABI]

Moerdogg, I'll help you this summer. Bring her up to Amesbury.

-Jim

[moerdogg]

Sweet, I'll bring tasty beverages!

[bedheadben]

Now that's how you get things done around here!

[WASABI]

Now that's how you get things done around here!

Ben, if you lived a little closer....however, you are more than invited to join.

[bedheadben]

Yaaa it's a little bit of a drive haha.

[adam777]

I used the heat gun method as well. Here is a pro tip that I've never seen come up: After I got the dimples pretty well fixed (they look great in pics and in person, I'm just very anal about them), I packed some styrofoam behind them to fill the little space between the bumper cover and the bumper core. It help even out a couple imperfect spots, helps keep the plastic "memory" from bringing the dimples back, and gives it a bit more resilience if someone bumps me.