Plastic bumper repair write up (2014 Cruze RS)

crown_chronivic

Junior Member
Joined
Apr 18, 2015
Posts
1
Reaction score
0
I realize that this thread is for Cobalts. But there really are no good Chevy Cruze forums on Tapatalk so here it is a quick write up on bumper repair and paint.
18c9cdb0a0c693541a274a6a2ad3dde9.jpg
here's what I started with. The rear bumper also had a 6" vertical slice through the plastic RS bumper trim which I don't have a shit of.
The first thing I would suggest if youre looking at repairing your bumpers is if you have any more damage than what I repaired you might want to just buy new bumpers I spent $300 on paint primer fillers epoxy and you could likely buy a bew bumper(not both) for that price.
But read on if you still want to repair those bumper covers
A Cobalt should have a similar system to mount the bumpers, assuming it does there should be a few screws in the front and rear wheel wells that screw into the side of the bumper covers. Once you get these out there will be a couple push pins under on the rear and quite a few on the front, you may find it easier to remove the splash guard(plastic piece right under the rad support) with the bumper the front bumper should also have some clips on top under the hood. The next step for both the front and rear bumpers is disengaging the clips that connect the covers to the headlights/tail lights and fenders I suggest starting at the wheel wells and using either a plastic trim removal tool or standard screw driver with the head taped with electrical or masking tape. Lightly pull the bumper covers toward you as you push on the clips with the screwdriver and work your way around it.
Once you get your bumpers off and stripped down (which is pretty straight forward, if you got the bumper covers off you dont need additional instruction to strip them) you may now sand them down. Use an orbital sander with 180-220 grit for this.
16980be367e141383fee8830b103b311.jpg
e6fdc59716268fa6bd38bb1ce577f635.jpg

Now I would take 80 grit and a block to the damaged area if it feels like the plastic is higher than the rest of the surface, another method is taking a heat gun to the area and pressing down, then take ice water and pour it on the damaged are while you press down both of these methods need to be done BEFORE applying your epoxy

Before you go out and buy your epoxy you need to test your bumper covers to see if they sre TPO type plastics, the ones on my Cruze were do its likely your Cobalt bumpers will be also. You can test them by taking a die grinder to the back of the cover if it melts its a TPO plastic if it powders it is not. If your bumper covers are a TPO plastic you need to go and buy a Plastic adhesion promoter, I used Sand Free. The adhesion promoter is a water solvent mixture that removes was and grease from the plastic surface.
Once your plastic type is determined and you are ready to apply your epoxy( which should be available at your local parts store, ask for a FLEXIBLE plastic repair kit which will include the plastic repair resin and another epoxy resin that you can apply paint directly to) you need to decontaminate the surface youre repairing. You can use a final wipe solvent or if you are certain there is no grease contaminants you can just wipe it with a shop rag.

If the surface is split or cracked you need to purchase some drywall mesh. I applied mine to only the back side as I only used the flexible repair resin and sanded it with 80 grit so that it was flush with the surface. I sanded it again with 220 grit just to get the sand marks out of the plastic. If your surface needs additional filling you can apply your epoxy resin and body fillingover that( neither body filling nor paint will adhere to the flexible repair resin, thats what the other epoxy is for) i however skipped this step in favour of using adhesion promoter and primer and body filling on top of that I dont suggest doing this as when you are shaping your surface you may sand down to the plastic again which will require repeating the process of adhesion promoter and primer until you dont get bare plastic.
Decontaminate the surface again before priming it. I used spray can primer, 1/2k high build primer is your best bet. You need to spray adhesion promoter on any bare plastic before priming it. I suggest using several coats of primer over the damaged area to avoid repeating the application of adhesion promoter and primer over and over.
Once the primer has dried youre ready to start sanding again. This time you wsnt to use a sanding block and 320 grit sandpaper. The block sander helps you find low and high spots. Plastic damage tends to have a kinda ripple effect( see photos below) the low spots can be filled with body filling, or if they are not too low you can just use body icing like I did which is like body filler but not as strong and easier to apply and sand
81405b23a23e8b9e4c3df924411977d4.jpg
41cdcf98bf828b5fb171e0f016767b4b.jpg

Once you have the shape you want and the rest of the bumper block sanded with 320 ( for the areas that are hard to get you can buy scratch pads(maroon colour usually) that will make it easier but sand as much as is possible. I should also mention when you are block sanding you want to sand in at least 2 directions and NEVER in a circle. You are now ready to paint. A cheap air paint gun can be bought for around $50 and will work just fine if you dont have access to one already. I also suggest buying air/dirt/grease filters for your air supply but I don't know if those are available for cheap. You will need to get your cars paint code. Its location depends on the make and model but it can usually be found under the hood, in the glove box, or the drivers door jam. If you still havent found it your local dealership can run your vin for you and pull up a paint code.

Decontaminate your surface again. This time I suggest using a final wipe solvent followed by a tack cloth.The paint needs to be reduced to a milk like consistency(pro form eurethane grade reducer works fine) you will need to strain the paint while pouring it into the paint gun. Follow your paying guns instruction manual to select the proper air volume and spray pattern, if youre new to this I suggest spray testing on a smooth surface first. If you are spraying metallic paint you need to A) paint the bumper covers the way they would sit on the vehicle (see image below but note that this image was taken after clear coating) and B) spray in multiple directions, just like block sanding. I like to spray with the gun about 12" away and just really light dust coats, especially with metallic. Also if you are spraying metallic I suggest starting at the bottom and making sure you dont run your hopper too low on paint as an uneven spray will be REALLY noticable. You need to do 2 complete coats like this, the first coat should be just light enough to give the second coat something to stick to.

The paint should be dry within a half an hour. When it is completely dry, wipe it with a tack cloth again and spray on your clear coat. I used Endura industrial enamel clear coat because Industrial clear coat will stand up to rock chips better than automotive, however this is a pricey road to take. Again spray 2 consistant light coats, check from several angles while spraying the second coat to make sure you dont have any dry spots. If you do have several dry spots it is better to let it tack up for a few minutes and spray another coat then to to risk getting a run.
d15553538d32606ac5732475bf95242e.jpg


In terms of paint environment you can do this in your garage, just cover anything you dont want overspray on sweep it out and blow off the walls and ceiling. Spread sone water on your floor making sure it doesn't end up on your paint surface. I suggest not having a fan or anything going for ventilation as it will kick up dust

I hope this helps somebody somewhere. I tried to be thorough from start to finish but this is my first writeup so feel free to add suggestions/experiences/constructive criticisms. Here's my final results, I also painted my emblems for that added touch
9672328f2de9bf2d84dc89f0349b9c01.jpg
e46a6b924f27f063a3ae39a6cdb74dfe.jpg
 
Last edited:

Members online

No members online now.

Forum statistics

Threads
7,430
Posts
156,457
Members
4,332
Latest member
Kpcasperson
Top