Hello all I'm new to the forum. I have a '99 cbr f4.It had a new paint job when I bought I and it looked great. Then as the weather got hotter the paint started to bubble. Now it looks terrible. So my question is: what is the best way to get the paint back down to the plastic or original paint so I can repaint it. I tried sanding a small spot but that method would take forever. I have seen products for removing paint from plastic automotive bumper covers but I'm not sure if it is safe to use on a motorcycle fairing. If anyone has experience with this please let me know.


Thanks

 

It should be safe, they are both made of ABS. If you have an air compressor, a DA sander with some 80 grit would work too. 80 grit - 120 grit - 400 grit dry then 400 wet then a fine wet scrubby pad (kinda like the green part of a dish sponge but its grey) for a good finish. And get some FLEXABLE bumper patch (like bondo, but for plastic) to fill in any gouges. All the supplies would probably cost less than $20 at your local auto parts or hardware store. The DA about $40-$100, I'd suggest Harbor Freight if you're only gonna use it a few times. They're pretty cheap, but you get what you pay for. I'm sure you don't wanna splurge for a $300 Dynabrade. lol. Just remember that the quality of the finish is 80% prep and 20% paint. Thats why the paint is bubling up now. You also need to use paint specific for plastic. I used to work for Roush Mfg. doing prep on all the Mustang and Dodge SRT plastics. Be patient and take your time, it'll turn out sweet.

 

i would just sand it down with like some 220 grit then wet sand with 600grit and prime. if you dont have any big holes or groves(after u prime they become very visable)i would just use some spot glazing putty to make the surface smooth. if it is plastic i would stay away from a da sander because u can possibly damage the plastic, if ur using fiberglass go ahead but plastic isnt a good look for a sander imo (work in a body shop). n honestly its going to take some time to get it to look perfect, there really isnt a quick way around prep and repairing so take ya time

 

Ive used mineral spirits in the past to remove paint from my F3 fairings. Its pretty toxic, but it worked. That worked to get the vast amount off, then I went with the 400 to even everything out. DO NOT USE 80~120 GRIT!!! That would dig way too deep, I used that grit around cracks for epoxy to adhere, not to remove paint.

If you have a lot to do, I would reccomend paint store *paint reducer*, its expensive but effective.

 

I've done this for a living. Working with raw ABS and painted parts that werent perfect. These parts went on $40,000+ cars i.e the Roush mustang, all Dodge SRT cars and trucks, neons (not quite a 40k but same process), magnums, chargers, daytona trucks (the ones with the viper motor and that huge wing on the back). And to clarify, you want the smaller palm held da, not the big one with a handle. You also want the soft backing pad, not the hard plastic one. If you do what kpnupe said then the sanding marks from the 220 will show in the final coat. And sure you could just use the 400 grit, but you're gonna gum up 30 pads before you're finished, as opposed to a couple 120 grit to strip the paint, then a couple 400 grit to take out the swirls from the 120, then a couple more 400 wet to take out those swirls, and one wet scrubby by hand for the best finish. And let the da do the work, you dont need to put alot of pressue into it.

 

Wow, I must have over done mine. I had a Red/Blk scheme and wet sanded down with 440 then 800 to clear out the scratches and 1000 to finish before the primer then hit back with 2000 after a few coats of flat black.

 

How do these self paint jobs generally turn out? How long do they last? I am very tempted to repaint my f4 but I am scared that I will miss the long lasting factory finish, as scratched up as it is.

 

I'd love to tell you great, but my bike is a flat black so it turned out great but there is no room for imperfections. Some of the bikes ive seen that people have shot on their own really turned out.
Just remember the clear, and wet sand wet sand. IMO

 

Put it this way, I did my own and dont plan to do it again!

Paint alone was $140! The prep and body work and primer was no problem for me, it was the damn final coats that had me pulling my hair out. Paint is what it is, if you abuse it its gonna be crappy, but it your overlly carefull and baby the bike you should have no worries.

I myself will be paying someone I know the next time I final paint anything! All the work up to that point, I feel comfortable doing. Just none of the damn dealing with flash times, runs, underspray/over spray.

 

I have a 96 1000f which has an immense amount of plastic and I did not realise what I was getting myself into. I did some research on the internet and I purchased a single stage paint from sherwin williams auto paint with some instructions from the salesman which caused me some problems between primers and sealers, there seems to be a big difference and you do not need either with the adhesion promoter.With that said, the best way is to sand the paint to the origional primer with 220 grit with some bare plastic showing because you really dont know when you get there.
I used a 5" hook and loop pad electric sander with variable speed then I switched to 600 grit to uncover the bare plastic. Then all the parts need to be washed andrinsed twice with a product called simple green,then dried. The parts then need to be sprayed with a plastic adhesion promoter spray canas the directions on the can recommend and the color coat must be shot before the promoter completely dries. I used a product by the name of bulldog. I sprayed three coats of color and the next day sprayed four coats of clear, I can not tell you how to mix the paint or clear with the hardener because different paint has different mixes, wherever you buy the paint they will let you know. make sure you get the paint from a place that is open when you plan to paint because I bought mine from a store that was not open on weekends and I painted it on a weekend and I needed some information so I had to figure it out myself which really sucked. After the clear coat there will be some orange peel, make sure you put a light first coat of clear to promote adhesion then at least three more good coats, the less you put on the more orange peel you will get. Then wet sand by hand with 1500 grit then buff. I am not going to say it is easy because sanding off the origional paint takes just under forever. I worked on my parts after work for a few hours a day for weeks. But good prep work and following directions it is not that difficult. My bike is not perfect but I am more than satisfied. When I learn how to post some pics I will.