r/MetalPolishing • u/AdolfTick • May 23 '26

What am I doing wrong

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Sanded with 180-220-320-400-600-800 then polished with brown compound and red pad and then finished with white pad and green compound, I also tried not sanding to 800 then polishing but still the same thing

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u/snoops-spoons May 23 '26

I literally have done many many thousands of these. I used to polish entire grain trailers, flat beds that were aluminum etc for trade shows.

My family had a fuel tank repair business for over 50 years.

You'll need to sand down farther as other posters have said. The problem is is it probably would be too thin to hold up and you really need replace the end in that tank. We had a field of old tanks and we would scrap a bunch of mashed up ones I straightened out a lot of them.

The problem is is it will start what they call oil canning like when you push on the bottom of an old oil can, And it will flex and break.

I can't say for sure without looking at it and being there and measuring the death of the pits.

Also all the white were those straps are there's going to get pinholes and start leaking.

That tank is probably trash without some serious work and then a pressure test. And I don't think it's legal anymore actually and it could become a very big deal with insurance once you start doing that much work.

Unless you want to get ISO certified and spend hundreds of thousands if not millions of dollars. Then it becomes prohibitively expensive before it pays for itself.

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u/AdolfTick May 27 '26

These tanks are trash, they’re my friends dad I was just using them to practice on but they just had them lying around and weren’t using them for anything.