A split plastic bumper is probably one of the most difficult types of repair to carry out on a vehicle. Not only do you have to completely seal the split to an airtight finish but you also have to reshape a highly flexible area that’s not always flat. The front and rear plastic bumpers generally have more curves and contour lines on them than any other panel so reshaping these can be a tricky thing.
The first thing that you need to be aware of when carrying out this type of job is making sure no structural supports or plastic brackets behind the damaged area has been broken or buckled. If they have then continuing with the split bumper repair and not fixing the issues behind the panel will cause you further problems down the line.
As mentioned previously you need an air tight seal on the plastic weld this is essential because when it comes to reshaping the area any pin holes that remain will expand when heated creating blisters in the paintwork which look unsightly and very unprofessional and cause the paint to peel or flake within a matter of weeks.
Another mostly overlooked part of a split bumper repair is the type of filler that is used. It’s not a case of one filler for all jobs but specific fillers for specific jobs. The best type of filler to use on a plastic bumper split repair is a flexible plastic stopper filler which will be able to flex with the plastic in variable temperatures and be able to maintain its shape without cracking or sagging.
Not all split bumpers can be repaired. If the split is over 30cm long or there is multiple cracks that spider out then its advised to have the panel replaced. Also not all bumpers can be plastic welded. Fibre glass bumpers are becoming more and more popular on modern cars and it this type of part that cant be welded, instead you repair the split by layering over additional fiberglass sheets or specific fibre glass filler and metal gauze to seal the split or crack.
So as you can see from the details laid out above splits on plastic or fibreglass parts can be fixed to an extent depending on size and location. In order to get a fully professional repair close attention to detail is a must with special care taken over the weld and prep stages laid out above.