Recently, my bumper was damaged in an accident, which also caused the headlight clip (circled in the image) to break cleanly. When the garage replaced the bumper, they applied some kind of black sealer to the clip. What would be the best way to properly repair it?

 

 

The proper repair involves plastic welding.  Basically need something hot enough to melt both edges of the break, then push them together and it should hold when it cools down.

A decent soldering iron can be used for this if you've got one.

Tbh though, if the glue/sealant is holding fine, I'd probably just leave it.

It can be joined by using "Solvent Cement" the kind used by plumbers to join plastic pipe.

It is a chemical action that causes the plastic to partly melt/dissolve and while the plastic is in that state it can be pushed together and held for about 5 minutes while it sets. Full strength takes about 12 hours.

For example: https://www.screwfix.com/p/floplast-sc250-solvent-cement-250ml/14295?tc=HA9&gad_source=1&gclid=CjwKCAiA6aW6BhBqEiwA6KzDc4CZ_k4ppS51MmnWAdCg-zV7xR18_6kn1Vzthso1qYOqv79ipAakKhoCiSMQAvD_BwE&gclsrc=aw.ds

I have also seen people Plastic Welding with a Soldering Iron using Black Cable Ties as the Filler for repairs like that.

10 hours ago, Tizer said:

I have also seen people Plastic Welding with a Soldering Iron using Black Cable Ties as the Filler for repairs like that.

I've watched the same YouTubes - fascinating process...

14 hours ago, unofix said:

It can be joined by using "Solvent Cement" the kind used by plumbers to join plastic pipe.

It is a chemical action that causes the plastic to partly melt/dissolve and while the plastic is in that state it can be pushed together and held for about 5 minutes while it sets. Full strength takes about 12 hours.

For example: https://www.screwfix.com/p/floplast-sc250-solvent-cement-250ml/14295?tc=HA9&gad_source=1&gclid=CjwKCAiA6aW6BhBqEiwA6KzDc4CZ_k4ppS51MmnWAdCg-zV7xR18_6kn1Vzthso1qYOqv79ipAakKhoCiSMQAvD_BwE&gclsrc=aw.ds

Does this require any sort of primer 

Best way to repair is to plastic weld it or you can get a repair kit on ebay .. Around £10-15 for normally come in pairs. 

12 hours ago, Jake0304 said:

Does this require any sort of primer 

No. 👍