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I need to get the license plate off a car that has one badly rusted Phillips head screw. The screw is so rusty that when I put a bit into the head the slots started to crumble. I moved to a smaller bit and it felt like I’d be able to turn the screw with that bit if the shaft would rotate without too much force. I didn’t want to apply too much pressure because it wasn’t moving and the slots are so delicate. If I break this screw, I’m not going to be able to drill it out — I’ll have to get it to a shop then (which would be tricky due to not being able to change the plate) — so I’d like to maximize my chance of succeeding on the first try with a chemical solution.
My question is: what chemicals can I use to try to loosen the rust without damaging paint or plastic on the car? I currently have PB Blaster, WD-40, and 3-in-1 oil. From what I’ve read it sounds like PB Blaster would be the best bet, I’m just not sure if it’s safe for the paint / plastic. I’m not sure if the trunk lid is metal or plastic. It’s a 2008 Hyundai Sonata. And if it matters, it’s baby blue color.
Once this is resolved, I’m going to fasten the plate with stainless steel hex head bolts or nylon fasteners.
Thanks for your help.
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There are many other ways I can think of to get this out.
As you stated, use PB blaster and use a P1 or P2 screwdriver and push hard while turning it to avoid stripping…
PB will be fine for the paint… Just wipe off any residue.. (as will all those others you have listed as well)… WD-40 is not really a lubricant…(The name means Water Displacer), but it does have minor lubricating qualities..
PB or Kroil is what I would recommend…
OR
A few gentle taps using an impact driver..
or this:
Also, simply drilling through what you have now..(a left hand bit may even unscrew it as you drill)
-Karl
The aerosol products are more than likely going to contain solvents that will strip the wax or to swell, craze, or dissolve a plastic piece. There’s only a limited number of solvents that will damage the clear coat, and I doubt these would be used in an over-the-counter product. The MSDS available on the product’s website will give a listing of the solvents.
If the 3-1 oil is in a dropper bottle, I would try that first. Alternatively, a 50/50 mixture of ATF and acetone could be applied to the corroded parts. Just be aware that acetone will definitely strip any wax and will probably damage an acrylic plastic. So apply the mixture to the screws appropriately.
I recently installed stainless steel screws with plastic snap-on covers after someone kindly tried to steal my plate. There are 2 pieces to each cover – the bolt head sits in one part and the cap snaps onto the lower part. These should be available at an autoparts store with all the other license plate stuff.
PB can be harmful to plastics, but I have used it for over 10 years with no ill effect…
Whenever I drop an engine I usually have to take off the lower splash shields, and such… A good blast of PB sometimes helps from the 10mm bolts breaking (and then having to drill them out and re-tap them).. Also using PB on parts within a wheel well (with plastic inside there)… Some overspray usually happens and I never have seen anything bad happen…
The point is, I have never seen PB damage a plastic body piece. I suppose if you soaked the pieces in them there could be an issue, but I have never seen PB do anything bad…. Most I ever get is an oily area where some of the overspray went… Never a hole, never melting…. wiping it away usually just results in a cleaner area…. I also have never seen any damage done to a painted surface (metal or plastic) with PB…
JMHO
A Sears flier was in the newspaper so I looked at the tools. Well, there was this red box they said contained stuff. I’m a sucker for things like this.
When I got it home I discovered it was filled with all sorts of driver bits. I don’t even own an electric driver but I have a Snap On ratcheting screwdriver that takes these tips. There’s all sorts of Phillips type tips in there.
I could have those screws out before you could say PB Blaster.
Take a pair of vice grips and lay them flat on the plate with the jaws centered on the screw head. Push very hard on the jaws toward the plate to push the plate back and grab the outside edge of the screw with the jaws and close the vice grips tight. If you can grab the outside edge of the screw head, turn it, and reposition the vice grips and do it again. I can get most screws that have a head on them out this way.
You can sometimes turn these by taking a pair of diagonal cutters and grabbing the head across its widest part. Sometimes you can get a really good grip this way and turn the screw loose.
Otherwise get a small chisel and hammer and tap the bolt counter-clockwise. Or drill a small hole in the center and use an easy-out.
Thanks for your help, @ToyotaKarl, @Hanneman, @Rob913meg, and @grg8888.
I’m happy to report success. I spent about 40 minutes repeating this routine: hit it with PB Blaster, insert screwdriver and tap gently, wait, attempt to turn. When I tried turning it, I tried both tightening and loosening, which seemed to help, especially since it seemed easier to turn in the tightening direction due to the state of the screw head. Eventually it broke free. At some point I realized the driver bit I was using might actually be smaller than ideal, so I visually tried to find the next largest one, which turned out to be a P2 like you suggested @ToyotaKarl, and that worked better. I also pushed hard as you suggested. I’m not sure what the smaller bit I was using is — it doesn’t have a number on it.
Some notes:
I recommend wearing goggles when doing this — the PB Blaster ricocheted quite a bit.
This immediately sent a stream of rusty PB Blaster running down the plate, so you might want to have something ready to wipe up / contain the stream with. I ended up sandwiching a paper towel under the bottom of the plate, and using another towel to wipe the runoff from the plate after each blast.
Also, the PB Blaster was immediately taking green paint off the license plate numbers when I wiped away the runoff. I’m not sure how that would’ve worked out if the license plate paint had gotten in the runoff and then on the car body.
The panel where the plate attaches on this car appears to be metal, with plastic (nylon?) nuts embedded. Hopefully the PB Blaster didn’t erode whatever the seal is around the nut. I wiped it off with a wet paper towel, but didn’t want to dump water on it and have it go into the screw hole.
I didn’t notice any harm to the paint from PB Blaster. After I got the plate off I rinsed the whole area with wet paper towels.
There were 2 spongy foam pads under the plate. One of them got saturated with PB Blaster. I tried to flush it out with water, but I didn’t get it all out. Maybe soap and water would’ve been more effective? I’m not sure how that piece of foam will hold up now, or if it’s attached by adhesive I don’t know how that’ll hold up.
As you can see here, the 2 screws from the rear plate have different threads:
I temporarily had to use those again and they both felt like they threaded in. (I left the one with the busted-up head quite loose so I’d be able to get ahold of it with pliers or something if need be.) I’m not sure how to figure out the correct thread so I can get new hardware.
[quote=”Rob913meg” post=99146]Take a pair of vice grips and lay them flat on the plate with the jaws centered on the screw head. Push very hard on the jaws toward the plate to push the plate back and grab the outside edge of the screw with the jaws and close the vice grips tight. If you can grab the outside edge of the screw head, turn it, and reposition the vice grips and do it again. I can get most screws that have a head on them out this way.[/quote]
Thanks for the suggestion. I can see how that might work, but I’d be worried about pushing the edges of the plate hard into the paint. Also, in this case I think the screw was tightened down pretty hard, so I’m not sure there would’ve been any room to do that.
[quote=”grg8888″ post=99181]You can sometimes turn these by taking a pair of diagonal cutters and grabbing the head across its widest part. Sometimes you can get a really good grip this way and turn the screw loose.
Otherwise get a small chisel and hammer and tap the bolt counter-clockwise. Or drill a small hole in the center and use an easy-out.[/quote]
Thanks for the suggestions. That first idea sounds like it would’ve been worth a shot. The hammer and chisel idea…like @Rob913meg’s suggestion, I can see how that could work, but I’d be afraid of what it would do to the paint. Re: the third suggestion, I don’t even own a drill, so I was really hoping a chemical solution would work, and thankfully it did.
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