Topic: Paint Repair tips needed

[Korven]

Due to a failing Tank gasket i noticed today, the first time i myself rode this bike since i bought it. It has been leaking gas and therefor the paint is loosening on the left side. Im gonna order a new gasket ofcourse, but is there anything i can do to fix this up with? since its only under tha gascap its not highly visible but still noticble. Seems like a waste to repaint the whole thing since its in decent condition. Are there any Nos or aftermarket touch up pens?

Edit: Found these 2-stage touch up pens, anyone used them? http://www.rsbikepaint.com/en-gb/products.php

[Menno]

When I see it correctly this is a candy custom gold tank.
Now normally one cannot repair candy paint.
However in this perticular case only the neck of the fuel opening is affected.
Take a sharp knife and get rid of all the paint on the neck.

Touch - up with candy is very difficult to do.
One option is to paint the neck black. Simply mask the tank and repaint the neck in black. Leave the part where the lid closes on the tank free of paint.
Onother option is to paint the neck in a (almost) matching metallic paint.
Or you could ask a professional painter to repaint the neck in candy gold.

[BenelliSEI]

Korben...... I had a similar issue with a very original tank (red) on my K1. Went to a huge cosmetics counter, in a local drug store. Bought three nail polish bottles (brushes included!), that looked close. Tested them on a scrap of steel sheet and chose one that was very close. As suggested, scrape the neck clean and then tape it all carefully. A few  coats later, I’m the only one that can see it. Dries very fast and damn close. I’ve been very kind to that area, but it’s actually holding well! Cheap and easy fix.

I bet you find something “close enough”. I think it was an acrylic lacquer.

[Menno]

Interesting suggestion.
Wonder how many different yellow- gold nailpollishes there are however...

[Korven]

Korben...... I had a similar issue with a very original tank (red) on my K1. Went to a huge cosmetics counter, in a local drug store. Bought three nail polish bottles (brushes included!), that looked close. Tested them on a scrap of steel sheet and chose one that was very close. As suggested, scrape the neck clean and then tape it all carefully. A few  coats later, I’m the only one that can see it. Dries very fast and damn close. I’ve been very kind to that area, but it’s actually holding well! Cheap and easy fix.

I bet you find something “close enough”. I think it was an acrylic lacquer.

Does it smear when your spill gas on it? Do you have a pic of it? As Menno says red is the most common and gold alot less common. But I guess you can always resort to mixing and experimenting on bare metal.did you use a transparent on top as "clear coat"?

[BenelliSEI]

You will be amazed how many golds there are! Not yet, I am very careful with fuel......

[Korven]

You will be amazed how many golds there are! Not yet, I am very careful with fuel......

My girlfriend will think I've become crazy when I take her out looking for nailpolish. If you can please link a picture of your results!

[BenelliSEI]

Sorry, bike’s is in storage.

[nvr2old]

If the paint line at the filler neck isn't sealed off from gas fumes, it's gonna do it again no matter what you use to touch it up with.  May I humbly suggest sanding the upper lip of the opening with 400 grit down to bare metal as well as cleaning up the area that has peeled back.  Mask off the tank really well so you don't hurt it.  I like the suggestion of just painting it black if you can't find a matching color.  Leave the lip bare and mask it off right at the line, paint it, let it dry, and then mask 1/8" into the bare lip and 1/8" below the new paint line and put a swipe of JB Weld in the exposed 1/4" and bury the paint line.  Remove the masking immediately so it doesn't dry on the tape.  That will seal the paint line from gas and/or fumes from ever getting under it and lifting it again.  I've used that technique with every gas tank I've painted and it works beautifully.

[Korven]

Yeah that's the main cause. Gas sipping behind the layers and then it became a pocket for even more gas. JB weld is just 2 component epoxy or is it something special with it?

[PeWe]

Not the best start but the good thing is only the neck. Really 2k paint covering the tank?

I should follow Menno's suggestions painting it black or a very close tone.

Then cover it with 2k clear. Or use 2K black only.
2k spray cans can be found in Sweden. If you need more than 1, Germany is probably cheaper and has more alternatives
https://www.spraydosen-shop.de/
SprayMax 2K clear spray can work really nice. The spray nozzle is closer to a real gun than other old style spray cans.
They have 2k black too.

I should also verify the clear coat's fuel and acetone resistance were not visible under it or front. If not resistant investigate how to do. If possible to sand the clear coat enough for another layers of 2k clear. Hopefully without the old paint lifting.

Even my 1k engine paint (Motip) withstand fuel when cured.

[Korven]

Not the best start but the good thing is only the neck. Really 2k paint covering the tank?

I should follow Menno's suggestions painting it black or a very close tone.

Then cover it with 2k clear. Or use 2K black only.
2k spray cans can be found in Sweden. If you need more than 1, Germany is probably cheaper and has more alternatives
https://www.spraydosen-shop.de/
SprayMax 2K clear spray can work really nice. The spray nozzle is closer to a real gun than other old style spray cans.
They have 2k black too.

I should also verify the clear coat's fuel and acetone resistance were not visible under it or front. If not resistant investigate how to do. If possible to sand the clear coat enough for another layers of 2k clear. Hopefully without the old paint lifting.

Even my 1k engine paint (Motip) withstand fuel when cured.

I have no idea what paint that was used. Are there really such a thing as 100% gas resistant paints tho? Most paint seem to disolve when exposed to gas, its just a matter of time. If gas gets trapped underneat the paint (since the paintlayers stretch inside the gascap, must be a miss from the paint guy). There is even a small amount of paint splash inside the tank, If i get problems later on with the fuel i know that the filter is probs clogged.

I dont have to resolve this issue now since the rest of the bike is kind of bad shape so i have some time to research diffrent solutions. Im gonna call the local painter and see what he says, might even get a price for redoing the whole tank (for reference) Just for the sake of science i will borrow an old/used bottle of my gf nailpolish to test how resistant it is to gas.

[Bootsey]

Leave the lip bare and mask it off right at the line, paint it, let it dry, and then mask 1/8" into the bare lip and 1/8" below the new paint line and put a swipe of JB Weld in the exposed 1/4" and bury the paint line.  Remove the masking immediately so it doesn't dry on the tape.  That will seal the paint line from gas and/or fumes from ever getting under it and lifting it again.  I've used that technique with every gas tank I've painted and it works beautifully.

Having seen this mentioned a few times, it sounds like a good method. Do you happen to have a photo of tank filler you've done?

Sent from my Lenovo TB3-710F using Tapatalk

[PeWe]

I guess the problem is 1k or water based primer, base and only the final clear that is a 2k paint.
When I painted my K6 in the early 80's at my job (paint both with waterfall and oven) it got 2k primer + 2k solid red (Nordsjö industrial paints) +  2k clear (Sikkens I had to buy). That paint was very durable. Very difficult to scratch since the clear was very protective.

I did a garage paint this winter. primer 2k+ base 1k + 2k clear. I masked it that way so the clear overlapped the end of the base to ensure no fuel creeping under it. I hope this will be OK.

Menno is the paint expert guy here that know how to do and details about the modern paints.

[nvr2old]

Leave the lip bare and mask it off right at the line, paint it, let it dry, and then mask 1/8" into the bare lip and 1/8" below the new paint line and put a swipe of JB Weld in the exposed 1/4" and bury the paint line.  Remove the masking immediately so it doesn't dry on the tape.  That will seal the paint line from gas and/or fumes from ever getting under it and lifting it again.  I've used that technique with every gas tank I've painted and it works beautifully.

Having seen this mentioned a few times, it sounds like a good method. Do you happen to have a photo of tank filler you've done?

Sent from my Lenovo TB3-710F using Tapatalk

Here's a couple of pics of a Suzuki tank.  It doesn't have the "neck" that a CB tank has but the technique is the same.  Gas will not penetrate a paint that has a hardener in it, whether it's a single stage, or a base coat clear coat system.  That's the beauty of catalyzed paints..but..if a paint line is exposed around the filler..the fumes will eat under it and cause the lifting.

 P1010001 by Larry Pearson, on Flickr

P1010002 by Larry Pearson, on Flickr

[Bootsey]

Here's a couple of pics of a Suzuki tank.  It doesn't have the "neck" that a CB tank has but the technique is the same.  Gas will not penetrate a paint that has a hardener in it, whether it's a single stage, or a base coat clear coat system.  That's the beauty of catalyzed paints..but..if a paint line is exposed around the filler..the fumes will eat under it and cause the lifting.

Thanks for that nvr2old, a picture is worth a thousand words. Always a pleasure to see your paintwork!