How to: Fix a plastic bumper

[mazdaspeed777]

As some of you know fixing a plastic bumper isn't easy. For one fiberglass will not stick to it very well and bondo will only stick a little depending on how you sand it. The other problem is finding a new bumper is hard and expensive, and when you do finally find one you have to give your left nut just to get it shipped to you. Then you have to paint it. By the time your done with the whole process you just spent somewhere in the neighborhood of $400-600. This repair only cost me around $40-50. So I recently did a bumper repair my self, and cheapely so I wanted to pass it on to my fellow mazda nuts. So here it goes.

First off here is what you will need:

Bondo patchs
Bondo
Bond plastic repair kits
80 grit sand paper
Finer sand paper(100 grit and up)
Sandable filler primer
Paint
Duplicolor clear coat

First off, a tip on keeping the painting process cheap is going to your local autopaint store and have them mix a quart of paint per your color coad and have them put it in a spray can for you. That way you can paint it your self.

1: Access the damage and figure out what you need to fix. Here is what I fixed on my bumper:

Fixed a hole where a trailer hitch went through my bumper, and I also deleted those ugly liscense plat wholes and mounted my liscense plate on my lower grille.

Deleted side marker lights and fixed crack from hitting a snow bank a while back.

2: Now on to some actual work. First off take these bondo patchs:

and put them behind any cracks and holes behind the bumper. These patchs are made of a metal mesh and ar sticky on one side so you can stick them to your bumper. These alow the bondo something metal to bond to.

3: Next take your bondo plastic bumper repair glue and spread it along the bondo patchs on the back side of the bumper to help the patchs adhear to the bumper. Also use this bumper repair glue on edges where bondo meets plastic:

This will keep the bondo from seperating from the plastic

 

[mazdaspeed777]

4: Now apply the bondo to areas you will be repairing:

Then sand it down with 80 grit sand paper. Remember the smoother you get the bondo the less you will have to sand. Another good tip is make sure to smooth the bondo out as much as possible on the endges when applying it so the bondo will have a harder time sepperating from the plastic. Then after sanding apply the bondo bumper repair glue that I mentioned in step three to the areas where the bondo seams to be seperating from the plastic.

5: Next apply more bondo over the areas where you use the plastic bumper repair glue for it doesn't sand very well, it says you can sand it on the package but its pretty much a lie.

6: Now sand everything again. A good rule of thumb is remembering you will be painting this surface later on so any minor bump or scratch will still show up after you paint it so make sure you have everything perfect at this point. After sanding everything with the 80 grit sand paper, sand everything again witht the finer sand paper. Your bumper should look something like this now:

7: Next you can start priming your bumper. I use the sandable filler primer so you can sand it and fill in those minor things that you could not sand out of the bondo

8: Now of coarse you can start painting you final coats. Make sure your in a good dust free bug free environment that is at least 60 degrees. I did about 8 coats of paint since a coat of paint from a spray can is thinner than a coat of paint from a paint gun. Allow each coat of paint 20 minutes to dry in between caots. After you put the final coats on and allowed them to dry you can add a few clear coats if you want. You should allow the paint to dry a good 24 hours or so before you apply clear coat for a clear coat once it starts drying will pull on the coats below so if you paint below isn't dry it will cause you paint to wrinkle and crack.

So thats that. There are probably a few minor details I missed so you if have any questions, comments, and something to add to this how to feal free to do so. Here is some pics of my after I finished it and re-installed it:

 

[mazdaspeed777]

Wow, I thought that this would accually help a few members. I hear and see a lot of mazdas with bumper damage. Well hopefully it will help a some of you out there not afraid to do a little do it yourself project. If any moderators check this out this would be great if you could move it to the How to section. Thanks

 

[fLyPiNoY7]

hows the color match?...thats the only thing that worries me with doing a diy for painting

 

[Antoine]

I'm sure it will be helpful...Thanks for your contribution mazdaspeed777! (thumb)

*Copied to the How-To Forum (original thread in Proteg based Appearance)

 

[Thekid760]

Awesome, I've been needing to fix my bumper thats been broken since I bought it.

How long did this take you to do?

 

[MazdaSpeeder]

I don't need this How-To now, but I am sure I will soon...thanks for the great write-up, ditto on the color matching question. Can you see a diff in the shade on the bumper vs the original shade of the car?

 

[mazdaspeed777]

I'm sure it will be helpful...Thanks for your contribution mazdaspeed777! (thumb)

*Copied to the How-To Forum (original thread in Proteg based Appearance)

Thanks for moving this for me Antone.

 

[mazdaspeed777]

hows the color match?...thats the only thing that worries me with doing a diy for painting

The color match is great! You mix the paint per your color code. The only thing is since its in a spray can the paint is an enamel. So for some reason they told me if you tried to put a clear coat on this type of paint it will wrinkle the paint. The body is only a little glossier than the bumper.

So I will probably get this bumper painted again professionally down the road but this was great for do it yourself.

 

[mazdaspeed777]

Awesome, I've been needing to fix my bumper thats been broken since I bought it.

How long did this take you to do?

This took me about two weeks on and off. But if I did it strait it only would have taken about two or three days. So I just drove around with no bumper for two weeks. I dont really care what other people think about my car. It was worth it.

 

[bikefst]

hey so for the damage on the bottom of your fender; did you remove any of the material around the crack to provide space for the filler to smooth it out? thanks!

 

[kpipalldaway2]

Wow Nice Diy

 

[mazdaspeed777]

hey so for the damage on the bottom of your fender; did you remove any of the material around the crack to provide space for the filler to smooth it out? thanks!

Nope, just closed it as tight as I could and patched it together with a bondo patch. Then bondo'ed the front and back of the bumper

 

[mazdaspeed777]

Wow Nice Diy

Thanks, just hope this helps a few people out. Glad to provide a survice

 

[kcbhiw]

Just in time. I accidentally schmanged a nice chunk from the bumper of a Tracer LTS that I'm building. Hooray 18 year old plastic. I think I'll give this a shot!

 

[mazdaspeed777]

Just in time. I accidentally schmanged a nice chunk from the bumper of a Tracer LTS that I'm building. Hooray 18 year old plastic. I think I'll give this a shot!

Good deal, good luck!

 

[dreckis101]

Good deal, good luck!

going to do this on my front and rear bumper this weekend.

 

[mazdaspeed777]

going to do this on my front and rear bumper this weekend.

Cool, let me know if you have any questions. I will be doing this again as well. I get two cracks in lower front bumper and one on my rear I have to fix.

 

[TheMAN]

Just in time. I accidentally schmanged a nice chunk from the bumper of a Tracer LTS that I'm building. Hooray 18 year old plastic. I think I'll give this a shot!

you realize this thread has been around for over 7 months now right?

 

[_ERIC]

what clear coat did you use? also great write up!