Sanding/restoring plastic. How to guide

[CHAINSAW]

This question comes up a lot, and I see a lot of bad advice given. This is a the proper way to restore plastic, the Body Shop way. If you perfer the rubbing with blue jeans, and mop n glo way, your looking in the wrong spot.

Now first off, I dont suggest grabbing your lightly scratched discontinued plastic to start with. Find some old ratty plastic to learn on, and practice on. My instructions are going to be detailed, and if you cut corners, it will not turn out good. Follow these to a tee, and your plastic will turn out like new.

Second, Im using plastics that are way beyond repair. These have very deep scratches, that would take days to sand out, and then your plastic would be wavy and not look good once its polished. I purposly left the edges rough, to show progress of the different grits of paper. I also purposly left a few deep scratches to show how a few over sights can ruin a good finish.


Here is the before pic. Notice the deep road rash on the corners of each side. I will be working on the bottom left corner only.

[CHAINSAW]

I only use 3M wet/dry sand paper. You can pick this up at about any auto parts store, and I believe Wal-Mart carries it.

Make sure your plastic is VERY clean! I suggest warm soapy water, and towel dry. Start out with 220 grit west sanding. All these instruction on sanding are given with WET sanding ONLY. Work on the deeper scratches first, then work out to the nicer parts. Work the sand paper in one direction with these two coarse grits. That way if you accidently get sand or something on the paper, you dont have a whirl wind of scratches to now fix.

Keep the paper and plastic wet at all times.
The second pic is what happens when you dont have your paper wet enough. The plastic will build up on the paper. With enough of this buildup, it will then start scratching your plastic. So keep lots of water on both, keep changing sides of your sand paper, and look at the paper often.

[CHAINSAW]

You will use the 220 and 320 to get down to the deepest parts of your scratches. To tell if you have done that... run water over your plastic. This will magnify the scratches so you know where to keep sanding. You can also dry the plastic completely, and the deep scratches will usually be shiney, while your plastic is dull from sanding.

Once they are all gone, move on to 400 grit. If you sanded all one direction like I told you to, this part will go fast. Sand just a little off the grain now. If you sanded straight down the plastic, to your hand about 10 degrees and sand with the 400.

Once the paper starts feeling like it is sliding off the plastic easily, move on to 600 grit. The 600 pretty much just takes out the scratches that was left by the 400 grit.

If you look at the edges on this pic, you can see how much of a difference the 600 compares to the 220 grit.

[CHAINSAW]

Now this is where your plastic starts to look good, and you'll want to hurry it along.... but don't!

You can use some 1200 or 1500 grit in this area, but I skipped straight to the 2000.
You want to use the 2000 as a buffer pretty much. You want to swirl the paper, go in straight lines, go at angles. Make sure the paper touches every part of your plastic at least a 100 times. Spend some time with the 2000, it will only make a killer finish once its done.

Once you have gotten the scratches out, the plastic will look like old Maier dull when its dry. Dont worry, your not done yet.

[CHAINSAW]

You will also need some buffing compound. This bottle is what I used. You can get something like it, but I only suggest what Im using.
Its 3M Perfect-It II Fine Cut rubbing compound.


You want to grab a soft cotton cloth. For my area, I used a drop about the size of a dime.
This stuff is applied just like car wax. You buff it on until it becomes dry or dull looking. Then take a cloth diaper, and buff it till all the compound is gone. I usually put 4 or 5 coats on, and buff it really good the last few times.

[CHAINSAW]

Once you have polished it out, you will have a shiney finish to your plastic. I have seen people then use plastic renew to leave a super shiney show finish, but its not really needed for an everyday riding machine.

This same compound also works great to clean up old chrome. Use some steel wool, a soft terry cloth towel, and this compound to remove water spots, and make it shine!!

Like I said up top, I left a few deep scratches on purpose. You can see them at the corner. See how the buffing compound sits in those scratches, and makes them like an eye magnet? That is why you need to take the time to sand out all of your scratches! If you get in a hurry, and cut corners, the plastic will look worse then when you started.

See the difference between the 220, clear down to the 2000? A little plastic sanded off will make a world of difference.
Notice the nice bowling alley slick surface.... nice.

I hope this puts to rest some myths, or half-arse ways of doing this. You can make your plastic look better then new again. It just takes time. I did this in 20 minutes start to finish, and the finish is not as good as I would put on my machine,,... but the steps are all there. A real riding moving machine, could take 3-4 hours on the front fender alone, to make it look good. It does take time, but it will be worth it.

[250rAL]

Give myself a pat on the back! That's almost exactly the way I did my gas tank except I used a buffing wheel in my die grinder and some plastic buffing compound for the last step. Autozone has a variety pack of sandpaper that has all the grits you will need to do the job.

[03 ORANGE SHEE]

i like how well detailed your instructions are, if i ever get a bad enough fender,ill be sure to use your help to make her shine!!!!

[corndawg]

i guess ive been doing it wrong, i usaually wet 600 it and then hit it with some of that good ole wax as you dry

[CHAINSAW]

Originally Posted by 250rAL

Give myself a pat on the back! That's almost exactly the way I did my gas tank except I used a buffing wheel in my die grinder and some plastic buffing compound for the last step. Autozone has a variety pack of sandpaper that has all the grits you will need to do the job.

Thats the ideal way, but take tools to do. These steps are also the same you would take to sand out a sun faded tank. I was wanting one of them to do this on, but a fender is all I could come up with.

[atckowalski]

You should do up a Tecate 3 gas tank or 20some.

[CHAINSAW]

I hate sanding, why you think I only did the corner?

[edog]

Very informitive

Thanks edog

[ohioplayboy100]

Thanks very much on the fender it made my honda ATC250sx look real good. But can any body help me with a sun and gas faded metal gas tank???? i woud greatily appreatiate it thanks....... mabey later i will post the picks of my trike on here.!.!

[CHAINSAW]

Originally Posted by ohioplayboy100

Thanks very much on the fender it made my honda ATC250sx look real good. But can any body help me with a sun and gas faded metal gas tank???? i woud greatily appreatiate it thanks....... mabey later i will post the picks of my trike on here.!.!

Metal tanks are pretty simple if you dont have any dents. There are a lot of factors that go into prepping a metal tank.

If you can, describe your tank shape to me. Like how many dents, where they are at, are there stickers on it, and so on. Pics would be nice also.