DIY: Repairing front bumper holes - Bumper Plug alternative

[CedarZ4]

So when I got my car last year, the dealer had already drilled license plate holes into my car. I took them off and instead of the expected 2, there were 4! Seems like most BMW brackets have 4 holes instead of 2... picture below.



I was not happy with this, but I thought a plate was better than 4 unsightly holes, especially on a yellow car (black car would have been better) so I left it on. I have seriously considered Bumper Plugs (or even DIY ones) but for $50 to add nipples to my car, I was less than impressed. It's been on the car for a year, but now that I have some time to mess around with the car, I decided to do patch the holes up myself (better than paying $500 for a repair and repaint at a shop).

Here is a DYI that I think some might find helpful. It is not BMW specific, of course, as this can be done to any car. Disclaimer: Please note your state's license plate laws (or just hope for no ticket)

First, I started looking for an epoxy/body filler to fill in the hole. People have done what I am trying to do on other forums, and many have just used normal Bondo Epoxy. However, Bondo Epoxy states that it should not be used for polypropylene plastic, which is what most bumpers are made of. That, and since Bondo is very stiff and a bumper is flexible, any flexing might cause it to crack or just pop out all together. I looked further and ended up with Bondo 280 Bumper Repair Epoxy. It says it's good for filling holes (exactly what I need) and have read good reviews.

Got it at Autozone for $11, and even Wal-mart sells it for $7. Comes with mesh patch and an applicator. The applicator was very useful (will get into it later).

So, first thing I did was wash the car with a non-wax detergent, or was supposed to anyway (I was lazy, so I actually just used water and then followed up with alcohol - main point is to remove any wax so the epoxy can bond). After that, I got an exacto knife to remove the edges of the holes that protruded due to self-tapping screws. This process was harder than I thought. I ended up just using a drill bit and slightly enlarging the hole One tip for those who don't want to enlarge the hole (although it was very minimal, not like the Bumper Plugs that require a significantly larger hole to be drilled) is to not be afraid to use force and cut. I was afraid so tried to push the blade at an angle (kind of like the scooping motion of a spoon) and this actually created even more protrusions. Anyway, after this is done, go over with alcohol again.

These are the protrusions you want to try to get rid of. You want it as flat as possible. If it's not perfect, it's ok. We can try to flatten it further in the next step.



After this, I patched up the area surrounding the hole with masking tape. I then used 600 grit sandpaper to sand it down really quick to remove any rough edges and bring down the protrusion even further. 600 seems to work well, but took too much time so I upped it to 320 grit. I was not concerned because I knew I was patching it, and would need to sand later when I paint anyway.

Here are two of the holes with masking tape, and sanding


After sanding, I took the masking tape off (since sanding removed some of the tape) and added new masking tape. Here is what I mean - the top is just after sanding and the bottom is after sanding and replaced with new masking tape


I then squeezed out the epoxy, mixed it together, and applied. The technique I used was to apply a large amount onto the hole. Then, using my thumb to cover the hole, pushed everything in. Re-applied epoxy, pushed it in with my thumb again. Rinse and repeat. I did this a few times until I felt like enough epoxy got in to fill the hole. This worked surprisingly well. Initially, I wanted to reach my hand behind the bumper to plug the hole from the back with my finger so epoxy doesn't leak out from the back. But as my father once told me, if you can't see it, then it's not there

This one is a bit blurry, but you get the idea.


After I thought I have filled the hole sufficiently, I applied one more layer, and used the sharp edge of the epoxy applicator to scrape against the bumper to remove excess to leave a flush surface. If it isn't to your liking, reapply another layer, scrape with the applicator again.


Although I have yet to get to this step, but I don't think it has to be perfect because you end up sanding it anyway. In the end when it is dry, you actually want a divot (concave) so you can apply touch-up paint. I made it flush with the bumper because I hear epoxy normally shrinks after curing. I hope this is the case. If it is not, no problem because I can always sand it back down. I just waste some time and a few squirts of epoxy. You can see it is relatively flat and flush with the surface of the tape. One tip for this is to make sure your masking tape is not too thick or don't apply too many layers of tape. My first 2 holes I had a thick layer of tape and I later realized it wouldn't matter how hard I tried to get the epoxy to be flush with the tape if the tape is too thick, because the epoxy wouldn't be level with the bumper surface anyway.



I did this for every hole and waited for them to dry. The packaging says 30 minute to cure and then you can sand. I might wait a few hours or maybe even overnight.

One more thing to note for the patching stage. The epoxy says it has a working time of 6 minutes or so, but I experienced less. So try to work fast, but don't rush it. If you do and you end up getting it on your car where you didn't mask like I did, don't panic! Just wipe clean with microfiber, then use some rubbing alcohol. Comes off like a charm!

Final result (and mess) after epoxy. I would imagine you can continue to drive the car and it should not affect the curing of the epoxy, as the labels says maximum strength within 30 minutes anyway. But you will have to explain to your co-workers your bullet holes!


I will update when I get to the next step, which is sanding down the epoxy.

[jparnes1]

Thanks for the write up, but none of the pix show up.

[rking117]

where the holes are rounded and sticking out of the bumper if you want to use another method instead of sanding you can use a air dryer and heat the area then use a nail cuticle tool to press the edges inward. Then go to your filling step. This will be much much faster and will result the same in the end. Be very careful not to get it too hot though a the bumper is made of heat sensitive material it could crack your paint. I had my sister run over a mailbox with my Fiat and it left a big dent n the bumper. A heat gun and a little bit of bondo fixed it right up. Then sprayed the area nd blended it and it was like new. Again use a ar dryer not a heat gun. And also make sure the you dont get it too hot. Just to where it feels hot to the touch not scorching hot. anything hotter will cause it to shrink or expand.

[CedarZ4]

Originally Posted by rking117

where the holes are rounded and sticking out of the bumper if you want to use another method instead of sanding you can use a air dryer and heat the area then use a nail cuticle tool to press the edges inward. Then go to your filling step. This will be much much faster and will result the same in the end. Be very careful not to get it too hot though a the bumper is made of heat sensitive material it could crack your paint. I had my sister run over a mailbox with my Fiat and it left a big dent n the bumper. A heat gun and a little bit of bondo fixed it right up. Then sprayed the area nd blended it and it was like new. Again use a ar dryer not a heat gun. And also make sure the you dont get it too hot. Just to where it feels hot to the touch not scorching hot. anything hotter will cause it to shrink or expand.

I actually did a similar subpar technique. I just used my finger nail and pushed the edges in between sanding. But your technique sounds like it would work, good tip!

Mind I ask if you have before/after pictures or could you PM your procedure for the dent fix? The plate holder actually left indentations in the bumper that I am still trying to figure out how to get that out...

In regards to my repair - I have already done 2 of the 4 holes, but haven't had a time to finish/update. My touch-up paint and clear coat won't arrive until Friday, so expect something during the weekend

[Hujan]

I have nothing to add except: Mmmm, Atacama Yellow, mmmm.

[Mayhem]

I am so glad I told my dealer not to drill those holes....

[rking117]

Originally Posted by CedarZ4

I actually did a similar subpar technique. I just used my finger nail and pushed the edges in between sanding. But your technique sounds like it would work, good tip!

Mind I ask if you have before/after pictures or could you PM your procedure for the dent fix? The plate holder actually left indentations in the bumper that I am still trying to figure out how to get that out...

In regards to my repair - I have already done 2 of the 4 holes, but haven't had a time to finish/update. My touch-up paint and clear coat won't arrive until Friday, so expect something during the weekend

Well my dent was pretty signficant. t was in teh underside of the bumper where it starts to wrap under the vehicle. It required a real paint job but since i have a good friend that professionally paints I used a heat gun to make the bumper maliable and then pulled it back into place with my hand from the back side. Then i had to use a bumper bondo on it. The trick was when i snadded the area i had to use a stick with sand paper wrapped around it and move in a V pattern. This got rid of the dent completely. From there I bought a little jar of the touchup paint from dr color chip and called my buddy. We masked for about an hour as to not get over spray and then he sprayed the dent on my back deck (that i did not mention in my last post) and he had me spray the dent on the bumper. Now when it cme to the clear he did that all by himself. Then after that was doen and since we did not respray the entire bumper we used a blending agent which got rid of the line from the factory paint and the repair. Now except for a scratch that i missed when sanding you cant even tell it was repainted. I will try to get a pic if my son brigns the car home ever again. haha

I used the following to make the repairs:

300 grit sand paper
800 grit sand paper
1500 grit sand paper
3000 grit sand paper

After each course of sand paper I sanded a bit longer each time to get rid of the sanding marks from the previous step. 300 when really fast since it is really course.

Then we used thin line tape and regular masking tape for masking. We just used regular newspaper in a couple layers over the areas we wanted to preserve.

I bought a huge 1 gal. can of reducer ( I still have it all except for 1 ounce or less.)

touch up paint and clear from dr color chip.

we reduced the clear only the color was fine for consistancy.
loaded it into my spray gun and turned on the compressor.

spray spray spray... color

wait. drink a beer.

spray spray spray... clear

cuss at bug that landed in wet paint.

wait. drink another beer.

didnt see bug anymore.

wet sanded with 3000 grit sand paper (when snading near the blended edges we sanded toward the factory paint only so that the edge doesnt flake up or roll up before it cures.

waited and drink more beers.

then we compounded with a wool polisher and cutting compound.

car shined and I was happy happy happy .... ready to sing Pharrell

this repair was not for the faint of heart. You have to destroy first before you rebuild.

[CedarZ4]

Thank you, rking! Very detailed write-up. I am very familiar with the process you took in regards to the sanding and polishing, however, wanted clarification on two things. When you popped the bumper back into place, were there still any indentations or was it just the paint that needed fixing? I am trying to understand what the purpose of the bondo was in your case.

It sounds like for you your dent was very large so you were able to pop it back up and do a repaint. Mine is very small and I don't think would work. It is the circular mark under the kidney and to the top-left of the hole.


You also mentioned getting your touch-up paint from Dr. ColorChip. Did you use their system or just their paint? From my understanding, their paint is different from OEM in that it is "blend-able/wipable" to work with their system. If it is the latter, I am very interested in knowing what "blending agent" you used to blend your clear coat with OEM clear coat, as that would help make my project much easier and with a better result. I was just planning on sanding it to match.

[rking117]

Originally Posted by CedarZ4

...When you popped the bumper back into place, were there still any indentations or was it just the paint that needed fixing?...

Yes there was a small crease in the bumper that had to be filled, sanded and then repainted.

Originally Posted by CedarZ4

...Mine is very small and I don't think would work...

The dimple or curcular mark will have to still be filled in order to make it flush and then repainted. Anything from the thinkness of smaller than a hair to a hole will need filling and then snaded smooth and then repainted. IF you simply sand and repaint you likely will burn through the clear, pigment, primer and then into the black plastic bumper too. Afterwards you will see a wave in the paint there which will be more noticable than the circle. You best bet is to do it right and fill, sand and repaint the area otherwise jsut leave it. Contact your dealer and ask them for the bumper guys phone number. They will know who you are talking about. he can do the job for you at a minimal cost and it will look great afterwards. (trust me they have one, cars get bumped all the time on lots)

Originally Posted by CedarZ4

...You also mentioned getting your touch-up paint from Dr. ColorChip. Did you use their system or just their paint?

I did not get their system. I just bought the touchup paint and clear. Their paints do have the solution to blend but it doesnt melt the factory clear enough to do a good job. Note that after we sprayed the clear we went over the edges with a spray of the blending agent. The overspray jsut disappeared and it looked like we had painted the whole bumper even though the pant was dry on most of it.

After that step we let the paint air cure for a week then woll buffed out any debris that was in the paint. Today you cant see anything where the touchup took place. It has been over a year since the repair.

Originally Posted by CedarZ4

...From my understanding, their paint is different from OEM...

Correct

Originally Posted by CedarZ4

...If it is the latter, I am very interested in knowing what "blending agent" you used to blend your clear coat with OEM clear coat...

That I will have to ask my paint guy about, it will be a couple weeks before i will likely see him again. However, I know he got it from a local paint supply store and it was specifically marketed as a blending agent.

I know he also said that he can make it with a reducer and something else but we did not do that.

[MichalM240i]

Wow, really impressive. Pity that in Europe we must have a front plates .

[Mayhem]

Originally Posted by MikePulpan

Wow, really impressive. Pity that in Europe we must have a front plates .

We also have to have front plates in many states. That never stopped anyone from removing them.

[MichalM240i]

Originally Posted by Mayhem

We also have to have front plates in many states. That never stopped anyone from removing them.

For me is this quite mysterious, because some cars from (for example) California do have front plate and some don't. What doese docide about it? Owner of car?

[CedarZ4]

Originally Posted by MikePulpan

For me is this quite mysterious, because some cars from (for example) California do have front plate and some don't. What doese docide about it? Owner of car?

As Mayhem has mentioned, many states in the US requires front plates. However, some owners do not like the look and do not put them on, or take them off completely regardless of the law (guilty, as charged ). Like you mentioned, California requires front plates, but some people run without them because they don't like drilling holes in their bumper or the look, and they run the risk of getting a ticket.

In regards to the thread. I was able to sand down the epoxy, and my touch up paint came (ordered it from automotivetouchup.com) and I painted over the epoxy. Unfortunately, I was involved in an accident last evening, and the bumper has been damaged. It will most likely need to be replaced, and if not at least completely repainted and cleared, so the project has been scrapped.

I do have pictures of my sanding down the epoxy and painting them, so for those who are interested in doing this DIY can PM me and I will send you the pictures or run you through what I did. For what it's worth, while I never got a chance to complete it I think I was on my way in doing a job where the bumper holes would have been barely visible.

[MichalM240i]

Originally Posted by CedarZ4

As Mayhem has mentioned, many states in the US requires front plates. However, some owners do not like the look and do not put them on, or take them off completely regardless of the law (guilty, as charged ). Like you mentioned, California requires front plates, but some people run without them because they don't like drilling holes in their bumper or the look, and they run the risk of getting a ticket.

In regards to the thread. I was able to sand down the epoxy, and my touch up paint came (ordered it from automotivetouchup.com) and I painted over the epoxy. Unfortunately, I was involved in an accident last evening, and the bumper has been damaged. It will most likely need to be replaced, and if not at least completely repainted and cleared, so the project has been scrapped.

I do have pictures of my sanding down the epoxy and painting them, so for those who are interested in doing this DIY can PM me and I will send you the pictures or run you through what I did. For what it's worth, while I never got a chance to complete it I think I was on my way in doing a job where the bumper holes would have been barely visible.

Haha, thanks man for explanation.

[Hujan]

Originally Posted by MikePulpan

For me is this quite mysterious, because some cars from (for example) California do have front plate and some don't. What doese docide about it? Owner of car?

This is just an example of Americans' willigness to rebel against the law. I don't have a front plate on either BMW even though California requires them. We also have window tint in excess of the legal limit. My sense is that the police don't care about these things as much, particularly on "nicer" higher-end cars driving in "nicer" areas.

This is the advantage of having more crime: the police have bigger priorities than tint and license plates on luxury cars. In Europe, they take this stuff much more seriously, it seems.

[mbetoni]

Originally Posted by CedarZ4

Unfortunately, I was involved in an accident last evening, and the bumper has been damaged. It will most likely need to be replaced, and if not at least completely repainted and cleared, so the project has been scrapped.

Cedar, so sorry to hear this and I do hope everyone involved was ok. I was following your thread and admiring your handiwork, so sucks that this happened. Bright side I suppose: New, hole-less bumper! Good luck with the repair.

[rking117]

dang man sorry