Sand or Paint strip

The final phase. Paint.
I've read numerous post on paint prep and the such. But what about the plastic parts on my 77 KZ 650? It currently does not have the
original paint. I believe it is a base coat / clear coat. I plan on doing the same for the new paint job. I was going to DA the tank with 80
grit down to the metal. What should I do about the plastic pieces? Has anyone use Rust-Oleum Aircraft Remover on the plastic?

Am I headed for disaster or in the right direction.

Due to plastics technology of the 70's I wouldn't us any stripper on them
Sand sand sand should be able to DA most of it, I'd go a little smoother than 80 on the plastic unless you have to repair damage

Not paint stripper on plastics, and definiitely not 80 grit. 400 max. Otherwise you will make deep scratches that will come back through the paint in time. Then a plastic primer, I use a rattle can, followed by primer filler, flatting etc.

Paint stripper is better on the tank, but it will attack any body filler skims which will need to be redone if neccessary.

I agree with the others about no stripper on the plastic. I'd try 220 grit and see how that goes.

IMO minimal flatting required with plastics, it is about removing wax polish and giving a key for the plastic primer, followed by the high-build primer. even a lip where the original graphics are under the primer can help with with positioning. With plastics you really don't want to remove paint, more about prepping for a coat of clear plastic primer.

Better to replace cracked plastics then try to repair in my experience, On stress points like the inner headlamp aperture on the early GPz's or side panel lugs cracks tend to return, whereas steel is a lot more restore-able

More than one way to skin a cat. This is my process.

There is paint stripper made for use on plastics but honestly i use regular paint stripper on plastic, albeit very sparingly, it makes surface of the plastic a little soft while the stripper is still present but as long as you don't let it sit on there too long its not really an issue. I follow up with 80 grit on a DA sander, and try to stay away from the edges. If you use paint stripper MAKE SURE YOU COMPLETELY REMOVE IT! even a little bit will continue to stay chemically reactive under the paint and cause premature failure. If you take it down to bare steel make sure you sand immediately before priming to prevent flash rust. I have done this on several body sets and not had an issue. I am in the process of painting a friends kz650 right now and literally did this all last week. Stripping it entirely does make a bit more work down the road but everything is of a known quantity. IMHO stripping it bare is good on a repaint because you really have no idea what quality of work is lying under the paint, OEM paint I wouldn't worry about. If the paint gets too thick the badges will not sit properly in the insets, which is also why i stripped this set, it must have been painted 4-5 times, really thick in some places. I use a good quality 2 part epoxy primer. Take the time to make some stands to hold the work up high so you can get a paint gun( or can) to spray perpendicular to the bottom edge. Alot of paint jobs end up thin on the edges because they cannot get the proper spray angle when the pieces are lying flat. I will be spraying this set blue on Tuesday then its just waiting on decals before a bunch more clear.

Tyrell Corp wrote: Not paint stripper on plastics, and definiitely not 80 grit. 400 max. Otherwise you will make deep scratches that will come back through the paint in time. Then a plastic primer, I use a rattle can, followed by primer filler, flatting etc.

Paint stripper is better on the tank, but it will attack any body filler skims which will need to be redone if neccessary.

+1
I almost ruined a side cover with stripper. 80 is way too harsh. Unless the current finish is peeling, rough it up with 400. No need to completely strip.

It's all about what it looks like years later, reactions, paint sink, cracks and scratches coming back and petrol paint 'lifting' can take months to appear.

Wet flat / key with 400 maybe a bit less even removes top layers of paint from resprays, as above I find the factory paint ok to paint over.

A while ago I took a risk on some GPz550 sidepanels, trying to save time I shot primer right over the previous respray without even a barrier coat. Sure enough months later the panels got a dose of measles. Whenever I try to save time it takes twice as long!

Dr Rot, don't you spend any time saved using 80 grit on extra high build primer and flatting?

Tyrell Corp wrote: It's all about what it looks like years later, reactions, paint sink, cracks and scratches coming back and petrol paint 'lifting' can take months to appear.

Wet flat / key with 400 maybe a bit less even removes top layers of paint from resprays, as above I find the factory paint ok to paint over.

A while ago I took a risk on some GPz550 sidepanels, trying to save time I shot primer right over the previous respray without even a barrier coat. Sure enough months later the panels got a dose of measles. Whenever I try to save time it takes twice as long!

Dr Rot, don't you spend any time saved using 80 grit on extra high build primer and flatting?

Yes, it ends up being about the same amount of time. The problem is clear coats are not "clean sanding" like high build primers are. Personally I'd rather spend my time sanding paint that is formulated to be sanded than gumming up a million feet of sandpaper on old paint. That being said, i typically wont strip OEM paint because i know the quality of work is good. its the resprays that freak me out. The only paint job I have ever had fail was because of paint failure from a respray that I did not strip. When you're spending $400 on materials plus 15+ hours you don't want to risk it IMO. a A good 2k primer will fill in the swirls form 80 grit no problemo, plus you still need to block everything out anyway. the epoxy primers are great for sealing stuff as they cure rock hard and are very inert. I usually do 3 stages of primer. (1) epoxy primer followed by light 120 grit. (2) high build primer with 220. (3) epoxy sealer followed by 400 then 600 grit then top coat and clear.

Like I mentioned I have painted many bikes this way, my buddy still has one of the bikes I first painted about 10 years ago and it looks great other than the standard chips and scratches bikes get over time. 1 component paints are never going to be as stable as 2 component. I cant comment on how my method would stand up over time with 1k paints, as I have never used them on body work.

This is just what I do, there are many different approaches to painting, its been working for me so far.