PDA

View Full Version : How to shave off Front License Plate and General Plastic Repair


r6_240sx
03-24-2009, 01:39 PM
Overview
Ever wanted to shave of that front license plate on your urethane bumper but didn’t know how? Well, now you will after reading this write-up! Not only that, but learning the fundamentals of how to repair plastic parts in general.

First things first, NEVER EVER FUCKING USE BONDO/FIBERGLASS RESIN ON PLASTIC. I see people doing this waaaay too much on here. If you don’t know why then you have some researching to do. Not only that, but Bondo is a brand of Body Putty and it FUCKING SUCKS. You shouldn’t even use that for what it’s meant for anyway. Go to your local paint jobber and buy some real shit.

The basics of what we’re going to do here are:
1. Shave the front bumper down.
2. Shaving will create holes through the bumper and will also weaken its structure, so we need to reinforce it in the back side.
3. Next, we’ll use plastic filler to fill in the holes, both front and back side of bumper.
4. Lastly, we’ll use a plastic finishing filler to give us that nice smooth surface and hopefully it’ll look OEM when it’s all done.

Sounds pretty easy right? Well, the saying “Easier said than done” applies here. It’s pretty messy and laborious. It makes you wonder why someone hasn’t made a plastic mold of the S14 JDM Bumpers along with the S13 Kouki Bumpers w/o a front license plate. I bet those would sell like hot cakes! Then again, maybe not.

------------------------------------------------------------
Videos
Okay, if for some reason you’re still reading, that means you really want to learn how to do this. So let’s get more in-depth. Here are some good videos to watch made by the companies who sell these products. They’re mainly videos of how to repair holes in your bumper, but it can be applied to what we’re doing because we’re technically doing the same thing.

Evercoat (http://www.evercoat.com/training.aspx) (MAXIM™ Two-Sided Bumper Repair Video)
Frame & Body Repair US 3M (http://solutions.3m.com/wps/portal/3M/en_US/3MAutomotive/Aftermarket/Solutions/Body_Dept/Frame-Body-Repair/) (Video - Plastic Front Side/Back Side Repair)

-------------------------------------------------------
Alternative Products
Our main product here is going to be our plastic filler. There are many products to choose from, but I only recommend Lord Fusor, Maxim (Evercoat), Duramix (3M), and SEM. I’m going to use Lord Fusor for personal preference, but I’ll post the other ones on here so you can take a look at it and decide for yourself which one is best for you.

3M
Durami Semi-Rigid Plastic Repair 04240
Applicator Gun, Automix Dispenser 08117
Reinforcement Patch 04904
Plastic Adhesion Promoter (Forgot part number)

Evercoat
Semi-Rigid Epoxy Adhesive, 891
Maxim Urethane Adhesive (887 Fast, 885 Medium, 891)
Multi-Purpose Repair Panels, 828
Plastic Adhesion Promoter, 883

SEM
Flexible SEM-Weld, 39708
Plastic Repair Reinforcing Tape, 7006
Flexible Polyester Putty, 39458
Flexible Polyester Glaze 39482
--------------------------------------------------------------

Lots of stuff to look at huh? They pretty much do all the same thing, it just comes down to price and brand loyalty. Now let’s get to buying all the shit we need so we don’t have one of those, “FUCK I FORGOT SOMETHING!” moments.

Here’s the Bill of Materials I used:
Rotary Tool (Dremel)

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02417.jpg
Grinding Bit & Cutting Wheel

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02416.jpg
Got sandpaper? LOL. You'll need (80, 100, 220 grit), don't forget to get some for DA Sander also if you're using.

Block Sander

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02412.jpg
Reinforcement Mesh
-Now I know I said earlier not to use Fiberglass resin, but this is different from Fiberglass. All the reinforcement does is give the plastic filler some “structure”. Similar to how the fiber strands in Duct Tape makes it much more stronger. If you can understand this concept then you’re doing great. You can get Tiger Kitten and Fiberglass Mesh at Wal-Mart or your local paint jobber. But the cheapest route is those Fiberglass Screens they make for the screen doors to keep bugs out, you can get this at Home Depot. Lastly, you can stick to one product and get Lord Fusor Bumper Reinforcing Mesh 700

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02413.jpg
Lord Fusor Extreme Bumper Repair Adhesive (Fast) 152
Lord Fusor Plastic Surface Modifier 602EZ

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02414.jpg
Lord Fusor Plastic Finishing Adhesive (FAST) 114 or equivelent. I used Evercoat Poly-Flex because I had some left over.

Putty Knife

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02415.jpg
Waterborne Wax and Grease Remover (Local Lord Fusor Supplier should carry this, make sure it's WATERBORNE not Solvent based.) I already have Southern Polyurethane's W&G Remover so I'm going to use this.

Masking Tape
Rags
Soap
Lint Free Rags
Dust Mask
Eye Protection

Optional:
Heat Gun
Air Compressor (Filtered)
DA Sander

Nearest Lord Fusor supplier:
Where to Buy (http://www.lord.com/Home/ProductsServices/Adhesives/FusorAutomotiveAftermarketProducts/WheretoBuy/tabid/3410/Default.aspx)
If you're in the SoCal area, I recommend Keystone Automotive in Ontario. They'll hook you up!

Steps
1. Clean the area down with soap, both front and backside. FYI: Back is probably going to be real dirty.
2. Spray the area with the Wax and Grease Remover, let it sit for a little bit to rise up all the dirt and grease and then wipe off with a lint free rag. You can use your FILTERED air compressor and blow it dry.
3. Sand down the license plate area to bare plastic as much as you can. I recommend using the 100 grit for this. Not necessary to sand down the WHOLE THING, but make sure you have sanded down a decent amount of surface area. My pictures with the filler feather edged should give you an idea of how much to sand.
4. Take your rotary tool with the grinding bit and start grinding the front side of that sucker down. Try getting it as flush as possible, don’t worry if you start getting holes on the edges, this is going to happen regardless. Just don’t go to crazy on the grinding and keep it at a low RPM.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02383.jpg
See how it's bulging out a little? Still got more grinding to do! Ignore my hood...
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02385.jpg
Much better!

5. Put the cutting wheel on and chop off that center circle. This step to some might not be necessary, but I did it because it’s a POS to sand down in the 3rd step which means poor adhesion when it comes to using the filler and the depth of the bore freaks me out thinking I have to fill that all in with plastic filler. Too thick of a plastic filler is a nono in my book.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02389.jpg
Those little tabs are hard to sand, just try the best you can.

http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02390.jpg
Don't forget the back side!

6. The parts you just grinded down now should be melted plastic. This is no good when it comes to adhesion. Scuff up the whole license plate area with your 80 grit. Try to sand down as much melted plastic as you can, so the whole area looks uniform. This way you’ll get good adhesion.
7. Now start cutting up your reinforcement mesh. You should have 5 total (Top L, Top R, Middle Circle, Bottom L, R).
8. Clean and wipe the area with W&G Remover.
9. Wait 30 minutes so the W&G Remover fully dries, take your air compressor blow off the area to get rid of any dust and spray the whole area with Lord Fusor 602EZ. Wait a couple minutes.
10. Take the masking tape and mask off the front areas with holes. Only press the tape down AROUND the hole leaving some space so when you fill it in from the back side it should seep through the hole into the front. I know this sounds confusing, but watch the 3M video I posted above to understand what is going on. Now wait a couple more minutes (10 minutes total from the end of step 9)
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02391.jpg
It's hard to see in the pics, but you can tell what I'm talking about in the bottom left corner.

11. While you’re waiting, start mixing up the Lord Fusor 152, but only make enough for 1 of the 5 sections. This shit cures FAST. (READ THE TECH SHEET THAT CAME WITH IT FOR DRY TIMES AND BASIC INSTRUCTIONS)
12. Take the reinforcement mesh and place it on the back side and spread the 152 on it. It’s ok to be liberal with the 152.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02392.jpg

13. Now take off the tape on the front side of only the section you used the putty on. If you did this correctly it should a good enough blob so you can take your putty knife and spread it across the hole.
14. Repeat steps 12-13 to each section until it is all done.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02393.jpg

15. Hopefully you did steps 12-13 PERFECTLY you can go straight to Step 19, but if you’re like me and you didn’t you have some extra work to do.
16. If you have a heat gun use it to dry the 152 on the front side. If you don’t have one you’ll have to wait awhile… Once it’s cured, take your 80 grit and scuff up the 152 on the front side.
17. Repeat steps 8-9 on the front side only.
18. Mix up a pretty big batch of 152 and lay it across the front side. Make sure to featheredge!!
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02395.jpg

19. Take your heat gun and dry up the 152.
20. Once it’s dry, scuff it up with the 100 grit (Evercoat Poly-Flex says 220, but IMO that doesn’t give it enough “bite”). Take your block sander and try to get it as uniform as you can. It doesn’t have to be perfect, the finesse is in Step 23.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02399.jpg
Needs more sanding.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02400.jpg
Good enough.

21. Repeat steps 8-9 on the front side only.
22. Mix up your Evercoat Poly-Flex or equivalent and spread it across the front side of the bumper with your putty knife. DON’T FORGET TO FEATHEREDGE! Some of you are asking why can't we just use the 152? Well technically you can, but I can guarantee that your arms will be sore from all the sanding. Hey at least you'll get a work out. But yeah, it's a waste of time trying to get a smooth finish with it, impossible if you ask me. Spend the extra cash to buy some plastic finishing putty.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02403.jpg
Wet.

23. Wait for it to dry (Read instructions for dry times). Now take your block sander with the 100 grit and get it as uniform as possible and then finish sanding with the 220 grit.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02404.jpg
Needs more sanding.
http://i152.photobucket.com/albums/s194/r6_240sx/bumper/DSC02408.jpg
Ohhhhh yeaaaa.

24. Wait a day, let everything full cure. There will be some shrinkage, hopefully you don't get any solvent pop-ups (meaning you didn't wait long enough to let the W&G dry. From here you can repeat steps 21-23 if you still aren't satisfied. But if are you happy with it... Now it’s ready for paint! Don’t forget to use a Plastic Adhesion Promoter if you paint it yourself!!!
-----------------------------------------------
If you're anal, you can go clean up the backside and make it look all pretty. I’m usually the type to do stuff like this, but this time I didn’t because I’m really tired and instead I decided to do this write-up to help out the community. Hope this helps. Feel free to critique on how this write-up can be improved. I better not fucking hear someone say they used Bondo or Fiberglass resin on a plastic part and it hasn’t cracked yet. I don’t give a shit, it’s bad practice, and it’s a disgrace to anyone that does real bodywork.

Cheers.

Edit:
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02644.gif
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02640.gif

genericforumname
03-24-2009, 01:43 PM
wow,awesome. I've been wondering about that for the longest time, though I guess thats just one more thing that I need to get off my ass and do...

DreamN
03-24-2009, 01:49 PM
Great write up.

Sonic Motor
03-24-2009, 01:56 PM
very nice brian!!

r6_240sx
03-24-2009, 03:05 PM
Oh damn jxn! You still remember me, haha.

I swear I'll head out to the meets again when my cars finished!!

BustedS13
03-24-2009, 03:08 PM
pics of finished product

cc4usmc
03-24-2009, 03:11 PM
I need to do something like this... except with a metal hood. Gotta figure out how too, but I guess it will be pretty much like this, except I'll use different materials.

DreamN
03-24-2009, 03:15 PM
what would you need to shave off a metal hood?

cc4usmc
03-24-2009, 03:24 PM
I don't need to shave off anything, I just need to fill holes. It had hood pins, but I wont be using them anymore. I picked the hood up for free, didn't know it had holes when I drove to get it though.. oh well lol.

Flicktitty
03-24-2009, 03:28 PM
Goood stuff!

this will need to be done.

INeedNewTires
03-24-2009, 03:59 PM
excellent writeup, i was going to do this on my USDM kouki bumper but ran out of time... Maybe soon

r6_240sx
03-24-2009, 06:10 PM
pics of finished productCar should be done this week.

I just need to play around with this new waterborne stuff they have out in socal.

Sneak peek:
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02421.jpg
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02420.jpg
Try to figure out this color! :naughtyd:

what would you need to shave off a metal hood?Only proper way to shave off metal stuff is WELDING THEM SHUT. The minor imperfections are then filled over with body putty. If you are truly skilled you can do this without any body putty.

Any other way is the wrong way.

Ruby240
03-24-2009, 06:38 PM
Why don't you get a glass mold made of your shaved bumper. Then make some CF JDM oem bumpers with shaved plate.

WoolyS14DET
03-24-2009, 06:51 PM
+1 Guy Nice

JohnnyDrfiter22
03-24-2009, 06:55 PM
is this an OEM bumper or aftermarket

bblack_91240
03-24-2009, 07:00 PM
This is a great write-up!!

^^^Its for the JDM Urethane bumper..

MELLO*SOS
03-24-2009, 07:06 PM
Always nice to see detailed step by step DIY write ups! Thanks for posting!

Taniguchi_Is_#1
03-24-2009, 08:56 PM
Try to figure out this color! :naughtyd:


midnight purple?


also, good writeup.

r6_240sx
03-24-2009, 10:44 PM
Why don't you get a glass mold made of your shaved bumper. Then make some CF JDM oem bumpers with shaved plate.My friend used to work for a plastic molding company, that makes plastics for Yamaha, etc. But with all these job layoffs, unfortunately he doesn't anymore. I would've been able to get a plastic mold for free if he still did.

If I was to do it now, it would cost money out of my wallet and I don't have the biggest cash flow right now for investing. :(

is this an OEM bumper or aftermarketThis can be applied to any type of plastic (TPO, ABS, TPU, etc.)

The same concept can be applied to Fiberglass too, just make sure to use Fiberglass resin instead of plastic putty.
midnight purple?


also, good writeup.Nope, not even close. I'm not really into flashy colors...

Ruby240
03-24-2009, 11:56 PM
My friend used to work for a plastic molding company, that makes plastics for Yamaha, etc. But with all these job layoffs, unfortunately he doesn't anymore. I would've been able to get a plastic mold for free if he still did.

If I was to do it now, it would cost money out of my wallet and I don't have the biggest cash flow right now for investing. :(

I hear ya there man. Find yourself a financial backer. Parents have 401k for a reason, lol!

blueshark123
03-25-2009, 06:33 AM
damn if u were local i would have let u do this to my bumper or i would of put up the money for u to make plastic molds of the bumper. how much u think it cost to make a mold of the bumper.

emersonLP
03-25-2009, 08:57 AM
The z33 has a indentation in the front bumper for the nissan hamburger. Would this work for filling that in or would there be a better filler for that type of work?

r6_240sx
03-25-2009, 02:45 PM
I hear ya there man. Find yourself a financial backer. Parents have 401k for a reason, lol!Too bad I don't have money to invest to begin with. Funding is coming from college loans, LOL.

damn if u were local i would have let u do this to my bumper or i would of put up the money for u to make plastic molds of the bumper. how much u think it cost to make a mold of the bumper.As for making a mold, I have no clue. I have never took a look into it, but shit ain't cheap I know that for sure.

The z33 has a indentation in the front bumper for the nissan hamburger. Would this work for filling that in or would there be a better filler for that type of work?You might have to do what I did in step 5 depending on the depth of the indentation. Technically you could, but laying on a thick layer of plastic filler or any filler in general freaks me the hell out. Having it too thick can lead to air bubbles and you won't notice it until it gets hot and the air pressure makes those bubbles more noticeable, and if you painted over it already you're pretty much screwed.

Another problem you have facing is figuring out the dry time, it might seem dry on the surface layer, but on the inside it's not. So when you start sanding it... :bash: I try to keep the thickness to a minimum.

But to answer your question, yes this is the plastic filler you need. Lord Fusor, SEM, Evercoat, 3M are all reputable companies. I would've gotten the 3M stuff, but you have to buy their Applicator Gun in order to use it. :down: 3M will always be too baller for me...

boske
03-25-2009, 06:02 PM
Do you know if theres a way to add material to the edge of a poly bumper? I'm working on fitting a cheap knock off kit, and it looks like they ground off too much of a corner of the back bumper where it meets the body. The edge happens to be about 3/4" thick, something could be thrown on there, but I don't know what would be best.

r6_240sx
03-25-2009, 07:04 PM
Are you sure it's polyurethane? Most knock offs aren't cuz it's expensive.

If you want my opinion on your question the answer is, no. Gotta pay to play for them quality kits.

You really think it's worth buying sandpaper, plastic filler, prep materials, etc. to do all that to a cheap knockoff kit?

r6_240sx
03-25-2009, 07:21 PM
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02426.jpg
http://i152.photobucket.com/albums/s194/r6_240sx/DSC02425.jpg

First shot of primer went on today, the surface is pretty uniform. I did however see what appears to be a small air bubble. I'm praying it's just a paint run, but we'll have to see tomorrow when the paint cures.

If it is an air bubble I can't believe I missed it. :bash::bash: Hopefully I can fix it. :hsdance:

boske
03-25-2009, 10:26 PM
Are you sure it's polyurethane? Most knock offs aren't cuz it's expensive.

If you want my opinion on your question the answer is, no. Gotta pay to play for them quality kits.

You really think it's worth buying sandpaper, plastic filler, prep materials, etc. to do all that to a cheap knockoff kit?

Its poly, and I have about $800 into it, I'm not too worried about buying some filler. When I said cheap, I was referring to the quality, same goes for most aftermarket body parts no matter what the cost.

sneakerjunkie
03-25-2009, 10:38 PM
I don't need to shave off anything, I just need to fill holes. It had hood pins, but I wont be using them anymore. I picked the hood up for free, didn't know it had holes when I drove to get it though.. oh well lol.


your welcome :wiggle:

r6_240sx
03-25-2009, 11:32 PM
Its poly, and I have about $800 into it, I'm not too worried about buying some filler. When I said cheap, I was referring to the quality, same goes for most aftermarket body parts no matter what the cost.Ahh ok. But if I'm imagining what I think you're trying to do, the answer would still have to be no if you were to just use body putty alone.

The body putty is like our skin, not like clay. It needs structure to work off of, for our skin it would be our skeleton.

If you can find a piece of polyurethane big enough, you can carve that out to fit the gap and as close as you can with the bumper. You can then get that welded with one of those airless plastic welders and then you can finesse it with the putty and what not. That would be the proper way to do it, but kind of overkill.

I would carve it out the best as i can, and instead of the welding it just use the plastic filler as the "weld" with a reinforcement mesh in the back. Kind of how you would repair a broken tab, if you get what I'm saying.

Should be something fun to do for a day if you're bored! :bigok:

burnsauto
03-25-2009, 11:38 PM
you REALLY wanna try to not use any time of filler besides the plastic repair. anything else really risks the chance of popping off later with any type of flex. plastic filler is strong, but doesnt like flexing one bit.

Just a few sidenotes if they were mentioned before (i just lightly skimmed the write up, nice one btw)

to get rid of pinholes, use a razor blade and force it into the pinhole, and then sand it down using 40 grit to break it down, then 80 to refine it more, and then finally 180 for primer.

DO NOT USE NORMAL WAX AND GREASE REMOVER. There is a special type of contaminate remover made just for plastic repair, and always use an adhesion promoter before you spray the PLASTIC SPECIFIC primer surfacer.

r6_240sx
03-26-2009, 02:29 AM
I agree with you. Plastic filler doesn't compare to the amount of flex polyurethane can do, but unfortunately there is no other way to do this without spending some serious cash on a new mold.

Good sidenotes btw, some were already mentioned though. ;) Good to see another knowledgeable bodywork person.