Jicafold

So I have this KHS I am refurbishing. It had some labels on it I removed which changed the color. I used some polishing compound on it without change. I am trying to even out the color change. Would wet fine wet sanding with like 3000 grit help? Thank you,

FBinNY 

The problem is that paint color changes over time because of things like UV and oxidation.

So, the paint under a decal will be closer to the "new" color than the rest of the frame. If you've ever removed a picture frame, or furniture that's been there a long time, you'll have seen this effect.

Gentle wet sanding might help, but may be too aggressive. You may have better luck with automotive rubbing or buffing compound, which does a better job blending old and "new" paint colors.

BTW. Most never notice because the transition is gentle, but if you look closely at a bike's top tube you'll find they're different shades.

It won't matter until you carefully match touch up paint color.

ScottCommutes

I would be cautious. It bothers you because you know its there, but to the rest of the world, it's not necessarily even perceptible. You could also put a new sticker there.

I would say the paint under the sticker is better, and the rest of the paint is a bit oxidized. Polishing compound is intended to help with this. There are gentle compounds, and also more aggressive compounds. There is also the hand vs. machine debate.

The wet sanding would achieve a similar effect - probably more aggressive.

I have no idea how much paint you can remove on a bike.

Also, if you simply let it be, the difference will fade with time and UV exposure.

Bill Kapaun

What;s wrong with a bike that looks like you actually use it?
I guess some people are of the mind set like those with large, jacked up, pick up TRUCKS with huge tires that haven't seen a lick of work in its' life.

zandoval 

Before using Sand Paper I would try some old Turtle Wax Rubbing Compound...

Jicafold

Like I was saying in the first post....I already used a polishing compound. Turtle Wax Polishing compound. I have some rubbing compound....thought that might be too aggressive. I understand fading and oxidation and all that. I was just trying to correct that.

ScottCommutes

​​​​​​https://www.amazon.com/dp/B0009JKGJ2...t_details&th=1

Old is a bit of a misnomer. Still very much in production/use. Just bought some this week actually.

ScottCommutes

https://www.amazon.com/Niteo-Product...000BO56JU&th=1

Looks to be more aggressive than the Turtle stuff.

Robvolz 

OK, the problem isn't the paint, but the clear coat. For you to wet sand with 3000, you will remove the clear coat before you get to the paint.

yes, its possible to even it a lil, or at least feather the color change, and then spray another layer of clear and wet sand that in.

Or,

I know, this isn't what you asked advice on…… a better or bigger sticker.

Robert

FBinNY 

If buffing compound didn't help, you might want to go v-e-e-r-r-y slow with wet sanding.

There are many types of paint, some are the same full depth, but others have a skin of sorts, and sanding through that will destroy the finish.

If you want to go ahead, find a hidden area, like inside the chainstays, or under the downtube near the BB.

Kontact

I thoroughly doubt you can fix this with abrasives - you would need to remove all the stuff that wasn't under the decals in an attempt to get down to the original color that they reveal. That means cutting through all the clear coat as well.

A handheld UV light might be more effective to get those spots to darken. Or, leave the frame in the sun for a few days and see if that helps.

ScottCommutes

I was working on two bikes this past weekend. The one I ride the most is an early 90's Diamondback. The paint is boring white. The bike has dozens of dings in it, and you can visibly see in those dings that the white paint is incredibly thick. I would not worry about sanding that bike.

The other bike was my daughters - a somewhat newer kids Diamondback with pretty paint. I was removing lots of huge stickers to make it less "boy". The heat gun worked. Good Off worked. However, the one time I tried both at the same time, I accidentally removed a spot of paint down to the primer in a few seconds.

I would guess that your bike, and most bikes, have thin, delicate paint like my daughter's bike.

Jicafold

Ok. I will leave it as is. Thank you.

wheelreason

No.

grumpus

I had a bike that was silver on one side and metallic blue on the other, because it had been left facing the same way in the sun for a decade or more. I eventually repainted it because I did some work on the frame, but otherwise it was just patina, part of the history of the bike.

ScottCommutes

So I messed around with some paint repair tonight. If your bike is painted black or white and has dings, I would recommend Rustoleum appliance touch-up paint. Cheap and easy. It comes in a little bottle with a brush in the lid. Enough to do a bike and perhaps your washing machine too. Dries in 10 minutes.

I next tried the Turtle stuff. A ketchup packet is about the amount that you need to do a bike - the container they sell you would last 10 lifetimes. Very tame. Didn't turn my cloth any color at all. Totally ineffective against faded paint next to stickers as reported. It does help get off road tar or adhesive or whatever might be on the bike. Highly effective on faded black parts - shocks, cranks, brakes, etc. Perhaps it works for getting swirl marks off of cars, but not particularly useful on a bicycle, except the black parts.

Then I went to wet sanding 800 grit on the white bike with all the touch up paint. This removed paint and the paper turned white repeatedly. Very good at removing stubborn dirty spots. Effective at smoothing over touched up and repainted sections that were obviously rough. Probably too course for most bikes, but perfect for my very beat up bike.

Mr. 66

I did some 600 grit and Meguires carnuba wax on the Synergy, the wax has more cut to it than others that I’ve used. I didn’t want to use the rubbing compound, I’m sure it would have worked fine though.