mx5cartalk.com

Hi all,

I have a cracked front bumper and am sick of its ugliness, so looking to repair it (must likely myself, the car is a diy project).

I'm thinking plastic weld into the crack, let it harden then reinforce the inside with fibreglass. However, I'm not sure how to get it all nice and smooth for painting?

Anyone out there got experience with bumper repairs?

Pic of the crack looking unhappy

Pic of the crack straightened up

(pics will rotate to proper orientation if you click them)

If it is an NA the front bar is polyurethane and the rear something else which escapes me. Urethane cannot be plastic welded but can be repaired. I used this stuff to fill holes in mine:

http://www.supercheapauto.com.au/Produc ... Kit/545159

I used the smaller kit which is cheaper but you might need the bigger one.

http://www.supercheapauto.com.au/Produc ... Kit/545159

Yeah, to fill holes, like when debadging, an ISO Plastic Parts Filler can be used.

Regarding how to smooth the plastic for paint after repairs are done.

This is as simple as lightly sanding it.

use a decent quality sandpaper, preferably a wet/dry type.

depending on how rough the plastic is, maybe start at 400 grit and move down step by step to about 1200, or maybe even smoother.

If a panel shop will be painting it, leave the sanding to them, as they'll do it to whatever grit/method works best for their technique and paints.