Ijaw Dictionary Online

How Automobiles Work

23 thoughts on “Can Body Filler Bondo Be Applied On Plastic Bumper Covers? Q&A

  1. Thanks so much for making this video to answer my question! You are full of knowledge!

    So pretty much, spray adhesive promoter any time I see bare plastic. After i put putty over the plastic and sand it down, I don't need to apply adhesive promoter anymore unless I see bare plastic again right?

    But then …… If I see bare plastic after sanding down putty, that indicates I've sanded too much… Which I probably shouldn't do.

    Sorry for the newb question :p

  2. Excellent. I've always wondered how to deal with plastic bumpers since I want to repaint my '77 corvette bumper and wasn't sure how to deal with it properly.I also followed your link to the video on fixing plastic. Thanks for that. Great stuff. I learned something today.Thanks

  3. Hi and thanks for the informative video. I'm a car body repairer from the United Kingdom. I've never heard of Bondo over here so could you please give me an idea of the UK equivalent! Best Regards.

  4. Thanks for a great video. I cant remember exactly,how long do you let the adhesion promoter flash before you apply filler. I guess I could read the directions. I remember when I was in school,I vaguely remember hearing about spraying a clad coat on before painting a plastic bumper cover for better adhesion. Could you explain that? Thank you

  5. I have a devilbiss flg5 gun that is having an issue.  It is having a hard time spraying material out.  The fan is very narrow now and cannot adjust it.  After trying to shoot clear I saw little clumps inside the air cap as if the clear is gumming up.  I've even tried over reducing the clear.  My other gun does not seem to have this issue.  What do you know about rebuild kits and is that a viable option?  Any tips for installing one?  Thanks!

  6. UPOL makes a filler specifically for plastic and they claim there is no need for ADPRO. It's called 706 and is a great product.

  7. Thanks for this, I have been using plastic filler on very flexible plastic bumpers for almost a year now after noticing regular body applied by previous technician cracking through the paint. I assumed it was ideal since its abit more flexible than the body-filler. Occasionally it wouldn't adhere well to the plastic so I assumed to use the promoter to help and it still peels sometimes.

    How long must the adhesion promoter be applied before applying body-filler over it?

  8. need help what would you recommend? I want to mold fiber glass fenders flares onto a abs plastic fender ? is there any way I can blend these two together so that it looks flush after I bolt them on? much help neeeded

  9. Thank you for the video.

    I may have a big problem, and any advice would be great.

    My urethane (plastic) bumper had embossed lettering in it.

    And I foolishly used Bondo to fill in the letters.

    I did not have any problems with adhesion. Everything stuck just fine. Then I sanded, primed, sanded, primed, etc.

    It's finally perfect, and I am about to get my car painted.

    But now I've learned that Bondo doesn't work on plastic.

    Am I screwed?

    I am now terrified that I'm gonna spend a ton of money on a paintjob, and then those fillings covering the letters will just fall out one day.

    Assuming the worst, do you have any advice on how to get the Bondo out now?


  10. Hello Donnie, I was wondering when I should use to fix a bumper crack on the outside. on the inside I would like to use something like JB weld and dry wall mes to secure it, but what about the outside. It is quite large crack! would like to mask of the hairline of the crack as much as possible.

  11. Hi Donnie. Great content and thanks for all your help. Your videos have helped me in doing a resto-mod on my '64 VW Bug. Now I have a question: Can I use "rondo" on plastic bumper covers?

    (For those who don't know, rondo is a mix of resin and body filler. I figure I could since the area I'm using it on is fiberglass. Also, rondo seems to be more flexible than just body filler.)

    I cut out a section of the bumper and modified the shape using fiberglass cloth and resin. I'm thinking about putting a layer of rondo on it to fill in some areas then sand it smooth. Thanks again!

  12. Thanks, I've actually never used bondo before. I take that back, I used it once for a dime sized chip and it didn't come out very well at all (I was 16). I recently used this 2 part epoxy wood repair by Elmers that worked pretty well. Considering using that on my rear bumper cover. Wonder if it matters if it's intended to be used for wood.

  13. Bondo is plastic. Fiberglass is fiber reinforced plastic. If you have cracks or a rip in your bumper cover you need to build up and reinforce the backside of the bumper cover first. You can also do it with epoxy resin and some cloth, or use long strand fiber reinforced bondo. If bondo won't stick, then neither will anything else…..The only reason bondo won't stick is if your surface wasn't sanded and cleaned properly or your mixture wasn't right.. You can also use fiberglass drywall tape and regular bondo to reinforce the backside. If you use fiberglass tape, I would suggest doing two layers for added strength. Sanding and cleaning is what makes the repair a good bond.

    Take the bumper cover off and sand the back side with 80 grit (3 inches minimum on each side of the crack and past where the crack stops). Wipe it down with lacquer thinner, acetone, or naphtha. Tape up the front side of the bumper cover to hold the cracks together and to prevent any repair compound from coming out through the cracks. Use Gorilla tape if you need the extra adhesive strength.

    Wipe it down with rubbing alcohol before applying material to the backside. Mix up some long strand fiber reinforced bondo and spread it over the cracks on the back side and keep the mixture within the sanded area so it won't lift on you later. Wait 30 minutes for it to harden. Remove tape from the top side. Sand the area with 80 grit, then V grove the cracks. Sand again with 220. Wipe down with same solution as used on back side. Fill the V groves with two part epoxy filler. Let cure, sand with 220. Wipe down. Apply thin coat of regular bondo as needed. Wet sand with 200, 400, then 600. Now you are ready to prime and paint.

    No matter what materials you use to fix large cracks or torn areas it will never be as flexible as it was…..but who cares….as long as it looks good and stays that way. I repaired my 03 Durango. It had ripped from the back wheel well. The tare was 14 inches long. It was dangling behind the back wheel and looked like hell. I taped it up with some clear packing tape and it lasted through the winter like that until it was warm enough to fix it. I reinforced the back side as noted above, then used regular bondo on the front side. It's been years and still no cracks.

    Good luck.

Leave a Reply

Your email address will not be published. Required fields are marked *