Standard rear bumper smoothed
This particular modification really is a two-sided story, a tale of DIY failure and professional success. I had decided that I wanted to smooth the rear bumper to match the front as I was really happy with the clean front end and in comparison the rear end looked quite cluttered.
Photo of the rear end at the time I decided to smooth the rear bumper.
A concept image created in paint.
I was really determined to complete this modification myself as I had built up some confidence in my ability after completing the interior work without professional help so I set about investigating the best method in smoothing bumpers which ultimately led me to practicing the art of plastic welding.
I bought a spare bumper from Dave at Eastern Autos so that my car looked fine whilst the new rear bumper was still a work in progress.
Polystyrene support structure removed.
Lamp recesses cut out so that plastic sheet could be welded directly into place. (This turned out to be my primary error during the build.)
Templates made to fill hole.
Templates transferred onto Polypropylene (Same material as bumper) plastic sheeting.
Blanking panel taped into position from front so it could be welded into position from the rear.
Weapon of choice - A heat gun with plastic welding nozzle.
A reel of polypropylene plastic welding rod.
It all seemed to be going rather well.
But I just couldn't get it all seamed together without it losing it's shape.
I tried to prise it apart and restart but then I lost the neat edge due to using excessive heat.
I decided that it was too late for this bumper, due to cutting out the lamp recesses there wasn't anything solid to help it keep it's shape. Bad times.
I proceded to remove the bumper currently fitted to my car using a 10mm wrench on the bolts visible with the tailgate open...
And on the underside of each side of the bumper...
I then removed the poppers underneath the rear number plate
Removed the number plate and the popper behind that...
To remove the rear lights you need to remove the screw on the relevant side behind the number plate.
The lamp can then be pushed towards the centre of the car and hinged out to access the bulbs / bulb connectors.
To remove the rear bumper completely I needed to find the rear number plate light connector from behind the metal bracket and unplug.
At this point there are just two further bolts to remove - One under each arch, where the bumper meets the wing - These are 10mm bolts again but have a Phillips crosshead centre so can be removed with a screwdriver or a wrench.
A gentle tug at each side pulling backwards away from the car and the job's done.
Bearing in mind that my cube is my only car I need to ensure I kept it roadworthy and legal so I needed to fit my new rear lights at this point so that I could drive without the bumper and standard lights. I found the perfect lights at Car Builder Solutions online, who are a specialist kit car supplier and stock lots of items which come in handy to people building custom cars.
I removed the plastic interior trim from the offside boot area which is where the main connection points are to the rear lamp wiring looms
Unfortunately it was getting dark and I wanted to get the job completed so I don't have any photos of this phase but it was a case of cutting the relevant cables, extending them, and feeding them into the area above the window before connecting them up to the new low profile LED lamps.
Photo with rear lights on.
Photo with indicators on too.
I have since moved the lamps down to the bottom edge of the window to space them out more, I need to do a separate page on that when I get chance.
Back onto the bumper...
Here is a side by side photo so that you can see how much shape was lost when it had been cut - the rear centre on the black bumper has sagged due to the three panels not being lined up correctly prior to welding.
This time I decided to leave the lamp structures in place and build up the centre with polypropylene box section and then build up with layers of polypropylene sheeting so that it was flush enough to be skimmed over with flexible filler.
Polypropylene box section from eBay.
Cut to size.
Test fit in place, and checking rear plate recess for size.
I then removed the lenses with a heat gun as the plastic behind was a better base to screw the layered plastic into.
With the lamps back in place I screwed the box section in so that it was a secure fit.
I then sanded back the tapered edge on the bumper so that it had a paint free surface for the new layers to be plastic-welded / filled to.
Three polypropylene strips cut to size and each screwed in turn onto the supports and strip behind.
Once I was happy with my work and I had taken the plastic layer as high as I could I took my bumper to Warnie at Panel Kraft to complete the body work and the paint. (As it happens more plastic welding was still required before the final skim over and I think the polypropylene strips were removed too. At least I tried!)
Main smoothing of centre section complete.
Test fit with smoothing complete prior to prior and paintwork. I also realised at this point that the Transformers Autobot badge stood out too much with the rest smooth.
The finished article. (Only change since this photo is that I have since fitted reflectors below the rear bumper instead of the adhesive oval reflectors that are on the tailgate in this photo.)
A concept image created in paint.
I was really determined to complete this modification myself as I had built up some confidence in my ability after completing the interior work without professional help so I set about investigating the best method in smoothing bumpers which ultimately led me to practicing the art of plastic welding.
I bought a spare bumper from Dave at Eastern Autos so that my car looked fine whilst the new rear bumper was still a work in progress.
Polystyrene support structure removed.
Lamp recesses cut out so that plastic sheet could be welded directly into place. (This turned out to be my primary error during the build.)
Templates made to fill hole.
Templates transferred onto Polypropylene (Same material as bumper) plastic sheeting.
Blanking panel taped into position from front so it could be welded into position from the rear.
Weapon of choice - A heat gun with plastic welding nozzle.
A reel of polypropylene plastic welding rod.
It all seemed to be going rather well.
But I just couldn't get it all seamed together without it losing it's shape.
I tried to prise it apart and restart but then I lost the neat edge due to using excessive heat.
I decided that it was too late for this bumper, due to cutting out the lamp recesses there wasn't anything solid to help it keep it's shape. Bad times.
I proceded to remove the bumper currently fitted to my car using a 10mm wrench on the bolts visible with the tailgate open...
And on the underside of each side of the bumper...
I then removed the poppers underneath the rear number plate
Removed the number plate and the popper behind that...
To remove the rear lights you need to remove the screw on the relevant side behind the number plate.
The lamp can then be pushed towards the centre of the car and hinged out to access the bulbs / bulb connectors.
To remove the rear bumper completely I needed to find the rear number plate light connector from behind the metal bracket and unplug.
At this point there are just two further bolts to remove - One under each arch, where the bumper meets the wing - These are 10mm bolts again but have a Phillips crosshead centre so can be removed with a screwdriver or a wrench.
A gentle tug at each side pulling backwards away from the car and the job's done.
Bearing in mind that my cube is my only car I need to ensure I kept it roadworthy and legal so I needed to fit my new rear lights at this point so that I could drive without the bumper and standard lights. I found the perfect lights at Car Builder Solutions online, who are a specialist kit car supplier and stock lots of items which come in handy to people building custom cars.
I removed the plastic interior trim from the offside boot area which is where the main connection points are to the rear lamp wiring looms
Unfortunately it was getting dark and I wanted to get the job completed so I don't have any photos of this phase but it was a case of cutting the relevant cables, extending them, and feeding them into the area above the window before connecting them up to the new low profile LED lamps.
Photo with rear lights on.
Photo with indicators on too.
I have since moved the lamps down to the bottom edge of the window to space them out more, I need to do a separate page on that when I get chance.
Back onto the bumper...
Here is a side by side photo so that you can see how much shape was lost when it had been cut - the rear centre on the black bumper has sagged due to the three panels not being lined up correctly prior to welding.
This time I decided to leave the lamp structures in place and build up the centre with polypropylene box section and then build up with layers of polypropylene sheeting so that it was flush enough to be skimmed over with flexible filler.
Polypropylene box section from eBay.
Cut to size.
Test fit in place, and checking rear plate recess for size.
I then removed the lenses with a heat gun as the plastic behind was a better base to screw the layered plastic into.
With the lamps back in place I screwed the box section in so that it was a secure fit.
I then sanded back the tapered edge on the bumper so that it had a paint free surface for the new layers to be plastic-welded / filled to.
Three polypropylene strips cut to size and each screwed in turn onto the supports and strip behind.
Once I was happy with my work and I had taken the plastic layer as high as I could I took my bumper to Warnie at Panel Kraft to complete the body work and the paint. (As it happens more plastic welding was still required before the final skim over and I think the polypropylene strips were removed too. At least I tried!)
Main smoothing of centre section complete.
Test fit with smoothing complete prior to prior and paintwork. I also realised at this point that the Transformers Autobot badge stood out too much with the rest smooth.
The finished article. (Only change since this photo is that I have since fitted reflectors below the rear bumper instead of the adhesive oval reflectors that are on the tailgate in this photo.)