Topic: Painting tank- prep issue with metal imperfections.. fill, grind, or other?

[kippstakes]

I just received a tank for my cb550 1974 and there are multiple imperfections in the metal. It looks like someone took a grinder to it to remove paint, or something. There are MANY crescent shaped grind marks in the steel that can easily be seen when painted. Ideas on how to smooth them out. They are very shallow, so I'm not sure about filler, but also deep enough that further grinding/sanding might create a warped look to the tank's surface.
How to proceed... not sure
Tips would be appreciated! Thank you
Hopefully the image works

[M 750K6]

That's perfect for a skim of filler. It's what I'd do. 👍

[BenelliSEI]

Agree….. if you primed it, look for a product called “Spot Putty” that can be applied (very thinly) directly over it.

[calj737]

Those marks appear to be from someone knocking a previous dent out, then trying to flatten the surface back to near original shape. A light coat of filler sanded down will remove them and make the surface ideal for paint.

[willbird]

There are primer types made to build up surfaces that have imperfections enough to allow them to be sanded flat. I really miss the days when plain old lacquer based primer was the right stuff, it was SO simple to work with. I would advise to follow all the mfg directions according to how fillers should be used and whether or not to use them over each other.

Bill

[Ozzybud]

Apply a skim coat of plastic filler on all the suspected areas. Follow up with an Epoxy Primer then a high build Primer and block to perfection

[Shtonecb500]

use filler, just skim in, do it a couple times.

[kippstakes]

Great. Thank you all for the replies. I'm a decent hand with filler so I will probably take that route- just wasn't sure if it would be indicated for such shallow fills.
Thanks again. Be safe.

[willbird]

Great. Thank you all for the replies. I'm a decent hand with filler so I will probably take that route- just wasn't sure if it would be indicated for such shallow fills.
Thanks again. Be safe.

We used to use that green water based spot filler stuff over lacquer primer. But with the modern paints I'd head towards a high buildup primer used exactly how all of the paint and primer mfg say to use it. The urethane paints do not suffer fools gladly from what I understand LOL.

Bill

[jgger]

I pounded mine out from the inside and then skimmed with the bondo glaze stuff in a tube. Being it was a fuel injected bike, I could get inside through the fuel pump hole. It only has thin coats and wet sanded using a sponge as a sanding block, like the double sided ones for washing dishes.

Good luck and have fun!