Sanding + polishing old plastics and tanks

[dclass_destroyer]

Hey guys. I have an old RM250 sitting around. I need advice on what kind of sandpaper I should use, and what kind of polishing method I need to restore the plastic tank, and maybe even the fenders. 

The plastic isn't stained or scratched, it just has a dull finish from all the wear and tear. I'm thinking to use wet sandpaper and then this Mother's plastic polish, and then a Cerakote plastic trim kit on the tank and airbox. 

 

 

What grit should I start with and work up to? Is there a better way to achieve the shine than the Mother's plastic polish? Also can you link the best paper to use? Thanks

Edited January 27, 2021 by lil_squid
typo

[axehandler]

I used a headlight restoration kit from 3m, everything in there to restore the plastic. 

[dclass_destroyer]

24 minutes ago, axehandler said:

I used a headlight restoration kit from 3m, everything in there to restore the plastic. 

What does it include? Do you have a picture of results by any chance?

Edited January 27, 2021 by lil_squid

[axehandler]

Photos not great but I am pleased with the results

 

[Leeb219]

Use wet & dry sand paper starting at around 3/400 grit working all the way up to 2000 grit. Then use a lambs wool polisher very lightly, they will come up like new

[Turboloader]

2 hours ago, lil_squid said:

Hey guys. I have an old RM250 sitting around. I need advice on what kind of sandpaper I should use, and what kind of polishing method I need to restore the plastic tank, and maybe even the fenders. 

The plastic isn't stained or scratched, it just has a dull finish from all the wear and tear. I'm thinking to use wet sandpaper and then this Mother's plastic polish, and then a Cerakote plastic trim kit on the tank and airbox. 

 

 

What grit should I start with and work up to? Is there a better way to achieve the shine than the Mother's plastic polish? Also can you link the best paper to use? Thanks

Dont sand that tank! You will never get it perfect. Just buy some mothers back to black polish and use a microfiber polishing rag and have at it. Or you can use a buffer and some polishing compound, but dont sand plastics. I think of any motor cycles center of attention, the main focus as the fuel tank, any bike. If its dented scratched, fugly, faded, etc, then its a deal breaker. There are places to send the tank off and let a pro do it. Just buff it out Squidward... 

[dclass_destroyer]

1 minute ago, M E T A L A C I D said:

Dont sand that tank! You will never get it perfect. Just buy some mothers back to black polish and use a microfiber polishing rag and have at it. Or you can use a buffer and some polishing compound, but dont sand plastics. I think of any motor cycles center of attention, the main focus as the fuel tank, any bike. If its dented scratched, fugly, faded, etc, then its a deal breaker. There are places to send the tank off and let a pro do it. Just buff it out Squidward... 

I kinda need to sand it, just polishing it will make it look rough. I scrubbed the tank with a razor blade a while ago, and it left the plastic with fresh yellow color but little ridges. I just need to sand them out, and then polish it, and apply some sort coating over it. (Cerakote trim coat, Back to Black, etc.) ?

 

I saw this video. I like the way it turned out, so I think I'll stick with this process. I got a sandpaper pack with 400 - 2000 grit, and all the time in the world. Thanks though ?

 

[Turboloader]

1 minute ago, lil_squid said:

I kinda need to sand it, just polishing it will make it look rough. I scrubbed the tank with a razor blade a while ago, and it left the plastic with fresh yellow color but little ridges. I just need to sand them out, and then polish it, and apply some sort coating over it. (Cerakote trim coat, Back to Black, etc.) ?

 

I saw this video. I like the way it turned out, so I think I'll stick with this process. I got a sandpaper pack with 400 - 2000 grit, and all the time in the world. Thanks though ?

 

Oh dear, well I assume you will need to sand it. Your arms will look like Popeye's after you are done. Ah the you tube video, hey it has a English narrator, so it has to be legit. LOL!?

[dclass_destroyer]

16 minutes ago, M E T A L A C I D said:

Oh dear, well I assume you will need to sand it. Your arms will look like Popeye's after you are done. Ah the you tube video, hey it has a English narrator, so it has to be legit. LOL!?

More muscle = better 

[Turboloader]

2 minutes ago, lil_squid said:

More muscle = better 

You know it!

[RetroRanger]

start w the underside of a fender that way youll know what your in for.

I think sand paper especially 400 will be too aggressive.

I have used metal polish like simichrome on faded and dulled plastics like the speedo lens and tailights and they have come out excellent.

 

[dclass_destroyer]

42 minutes ago, RetroRanger said:

start w the underside of a fender that way youll know what your in for.

I think sand paper especially 400 will be too aggressive.

I have used metal polish like simichrome on faded and dulled plastics like the speedo lens and tailights and they have come out excellent.

 

Idk, it worked in the video. He actually used 320 grit first

[dclass_destroyer]

15 hours ago, RetroRanger said:

I have used metal polish like simichrome on faded and dulled plastics like the speedo lens and tailights and they have come out excellent.

So you're saying that metal polish will work on plastic? When I'm done sanding out the imperfections, can I use it to shine them up?

Edited January 28, 2021 by lil_squid
typo

[dclass_destroyer]

Back to this topic. I'm going to start sanding down the tank (wet,) until I get a nice even surface. After that, what steps should I take? Buff it without compound, aluminum polish, trim restorer?

[Turboloader]

4 hours ago, lil_squid said:

Back to this topic. I'm going to start sanding down the tank (wet,) until I get a nice even surface. After that, what steps should I take? Buff it without compound, aluminum polish, trim restorer?

Buy a new tank? Step 5a??

[Pigsfly]

Hang on a minute what’s all the fuss about sanding plastic’s

 

First thing you really need is patients and lots of it, 400 grit is fine for deep scratches or cuts , Like others have said work your way up to 2000 grit. But it does take time my friend.

 

I have sanded many plastic bits on my motorcycles and what you will need is an electric hand sander And wet and dry paper.

My method is Keeping the area you are sanding moist with soapy water and and sand away all those scratches. Now be careful don’t get The electric sander wet, 

Now when it’s smooth as a babies bum it’s time to get the heat gun out To bring out the shine back in the plastic. Here’s a picture of a tank I’ve done half and half for comparison. I suggest if you’ve never used a heat gun on plastic before you get an old piece to practice on. 

 

[Turboloader]

3 minutes ago, CRJohnny said:

Hang on a minute what’s all the fuss about sanding plastic’s

 

First thing you really need is patients and lots of it, 400 grit is fine for deep scratches or cuts , Like others have said work your way up to 2000 grit. But it does take time my friend.

 

I have sanded many plastic bits on my motorcycles and what you will need is an electric hand sander And wet and dry paper.

My method is Keeping the area you are sanding moist with soapy water and and sand away all those scratches. Now be careful don’t get The electric sander wet, 

Now when it’s smooth as a babies bum it’s time to get the heat gun out To bring out the shine back in the plastic. Here’s a picture of a tank I’ve done half and half for comparison. I suggest if you’ve never used a heat gun on plastic before you get an old piece to practice on. 

 

That is purty as a peach.