Metal Finishing

If this has been asked, sorry, my searches did not pull anything up. Provide the link and I will read/research.

I am planning on sandblasting a few pieces along with grinding and sanding (the bulk, flat surfaces) to remove rust and paint. They were painted and now covered in rust. Once I am done removing the rust (and paint) and have the finished surface I want, how should I treat it?

Here is want I have found so far:

  1. When you flash metal (sand blasting, grinding etc), the metal is subject to flash rust.
  2. I could treat the metal just after ‘finishing’ it with a product to keep that from happening.
  3. I have tried to paint the projects just after grinding and something it works (no rust) and sometimes it does not (rust seen through the paint).

So, what I am doing wrong? What do I need to do (buy and how to treat)?
How to polish / finish the metal?
How smooth does it need to be?

This project will have me working on steel - not sure of the grade or type of steel. One is a tube piece and the other is rolled steel that is flat with two sides welding to the flat part (top with two rails).

Thank you.

You can use wd40 or any oil to stop the rust. It will require acetone or another good quality solvent/thinner to clean it all off before paint/surface treatment of choice. Good luck!

Jeff Eck


Grinding leaves oxide residue behind depending on the kind of stone or abrasive you are using. For my projects I would do all the metal shaping and forming and then sand blast and then apply primer and that always ended with a nice product. Make sure you wear gloves after sand blasting. The oils on your fingers will contaminate that nice raw surface.