Ripped bumper holes... how would you repair them?

[harrymaneuvers]

Ok so I bought a JDM bumper beam and bumper... the problem is that 90% of the holes for the mounting pins are ripped or torn open.
https://sl-i.net/FORUM/images/imported/2011/04/DSC07014JPG-1.jpg


Similar to this but in most of the cases... there is no missing plastic... it is just ripped in the middle of the skinny part (between the hole and the edge of the bumper.)

How would everyone go about repairing this to be super strong?

I have thought about:

Epoxy glue/weld a really thin washer underneath the hole.

Cut a small strip of a mending plate with spikes:
https://sl-i.net/FORUM/images/imported/2011/04/26493891-1.jpg

Then pounding the plastic onto the plate, forcing the spikes through the plastic, then covering in epoxy/jb weld.


I was hoping for some more ideas on what would be cheap, easy and strong.

[xoSubieLegacyxo]

There's a plastic "bondo" that basically gets hot with a reaction with another product, and then can be molded into whatever you want. We use this product (I think 3M makes it) a lot in the collision lab at college.

this is what it looks like (minus the special gun!)

https://sl-i.net/FORUM/images/imported/2011/04/3d97a0f989aa8d52f3b2b2a5cc51-1.jpg

but its a little on the expensive side. Your method "should" work too!

[harrymaneuvers]

Hmmm... I will have to check it out.

[httrdd]

How about taking a tin/metal plate on the space where the hole was, drill and rivit the metal to the plastic, then drill your hole like stock. Should be clean.

[harrymaneuvers]

So just rivet a square (or circular I guess) piece of metal under the bumper covering the hole? Using 1 rivet on each side? Then just drill out the hole??

Sounds good to me... but if the bumper got snagged on something again... I would think that the rivets would be just as easy to pull forward through the plastic as the bumper pins were to begin with...

[httrdd]

Then don't snag it on anything! Its only plastic so it will rip somewhere. The metal will be for reinforcement for the clips or the bolts that hold the bumper on.

[Baddog]

Curious about other options as well. I dunno how to "rivet" things. My bumper is the same way on one side and it is just annoying to look at. I was going to just drill a hole into the fender and into the bumper cover and run a bolt through it and a washer and nut on the top.

[mycargoesvroom]

I had the same issue on both sides of my WRX bumper. What I did was take a washer with a hole roughly the same size as the gap and JB welded that bitch on the inside of the cover. Throw a bolt/nut on it and call it a day.

[httrdd]

Yea that would work well too.

[harrymaneuvers]

So I ended up taking a machine washer (Very thin and strong washer) and Plastic Epoxying it to the bumper... it was strong enough to lift the entire bumper up with a hook going through 1 of the repaired holes...


It was MUCH stronger than I expected. It just looked a little sloppy because you just goop on the epoxy. Next time I am going to wait for it to cure half way (but is still impressionable) and press a cut off wheel or piece of screen over it to press a diamond pattern into the epoxy and even it out... I think it will give it a much nicer look.

[Baddog]

So basically you "glued" for lack of better word a washer to the bumper? Just trying to picture exactly what you're doing so I can do it my self! Thanks!

[harrymaneuvers]

Yep!

I roughed up both the washer and the plastic with some 500 grit sandpaper before gluing.


The only suggestion I would make is to press a texture of some sort (like a screen or a cut-off disc) onto the half-cured glue so that it doesnt look like frosting on a cake when it is done... with dips and peaks and just an overall uneven surface.


Also make sure that you get a machining washer which is really thin but strong. A thick washer will make it hard to use the same bumper clips/pins

[d1giPhux]

I need to do this soon since ANDIVIC sold me a bunk ass JDM bumper with almost all of the holes busted. I am going to plastic weld mine using the $20 plastic welder from HF. Going to use wire mesh, and then fill the mesh with plastic for some new tabs. Hope it will work. Videos of such repair here:

http://www.youtube.com/watch?v=NPnW6F_LOYw

Also one using that glue / plastic welding stuff 'fuzor':

http://www.youtube.com/watch?v=dgqnYNU8Mqc

[harrymaneuvers]

I am not sure which plastic weld you are talking about but I used the $5 plastic epoxy from ace hardware (double syringe) and it was WAY stronger than I could have ever imagined.

[GTDrifter]

i've actually been in the process of throwing together a diy for this using some videos from youtube
http://www.youtube.com/watch?v=NPnW6F_LOYw

[d1giPhux]

Yeah, thats one of the videos I watched when searching around. I got the mesh and everything, should be pretty sweet onces I finish. Just pisses me off when you buy something off someone and they 'forgot to tell you' all the tabs are broken. Like wtf.

[GTDrifter]

just don't buy the airless plastic welder from harbor freight. I did and the tip bent too easily and then snapped off when I was fixing the second tab (out of 6 broken tabs I'll add)

resorted to using a solding gun and the plastic weld rods which worked better than the harbor freight welder

[Baddog]

What is everyones though on just drilled out a new hole in the bumper and on the fender. Running a bolt through it and a washer/nut on the top?

[GTDrifter]

it could probably be done but you also have to make sure the holes line up and all that good stuff...plastic welding it together isn't that bad, maybe takes 5-10 minutes per broken tab to repair

[Okin DaVanh]

it could probably be done but you also have to make sure the holes line up and all that good stuff...plastic welding it together isn't that bad, maybe takes 5-10 minutes per broken tab to repair


Exactly.

New holes, won't resolve your problem, and could cause warping in time and in heat/sun if not done right. Take your time and do it right. It'll be worth it. I've been plastic welding parts for over 14 years, primarily on sportbike parts. It's all about choosing the right rod for the right material.Cleaning the area real good will determine the final outcome too. If you don't clean it good, the contact will be compromised resulting in premature cracking and welds failing. After welding an area, I like to reinforce the area with mending cloth and some 2 part 3M plastic bonding adhesive to make sure things won't crack in the future.

[Baddog]

I don't even know where to begin. But I did Plastic Epoxy a plastic washer to the bumper and it has been holding up the past few days. I have even bottomed out my bumper on dirt roads. Still on there, we will see.