DerbyDad03 on Mon, 25 May 2020 05:41:05 -0700
(PDT) typed in rec.woodworking the following:
On Monday, May 25, 2020 at 8:15:47 AM UTC-4, Dr. Deb wrote:
On Monday, May 25, 2020 at 1:58:29 AM UTC-5, DerbyDad03 wrote:
Asking for a friend...

The image below is part of a steel weather vane. As you can see, it's rusty and
getting worse. My friend wants to remove the rust then clear coat the piece to
prevent the rust from coming back.

You can't really tell from the image, but there appears to already be some type
of (uneven) clear coat on the piece already.

What's the process to remove the rust and existing coating without damaging the
metal and what's the proper product to prevent the rust from coming back?

https://i.imgur.com/bk3eTz5.jpg

Thanks!

Derby, there is a polymer that converts rust to an epoxy like substance. Car restorers and repair shops know about it. I first ran across it in the late 80's. Now, it would be nice if I could tell you the trade name, but the memory files are rather spotty back that far. ;-)

The rust is really just surface rust. I don't know if there is even enough to "convert". Besides, I
think it would come out very uneven, consider that the rust is uneven and the owner wants the
bare (but protected) metal to show.

I think whatever clear coating is on there should come off too since it obviously isn't providing
any protection.

I'd say that the clear coating has worked, otherwise all of it
would be rusty. I suspect that the coating developer a small hole,
and the rust began there. You're options are to remove all the loose
coating, the rust, and then refinish. And inspect regularly, it can
be yearly, before the start of the rainy season, what ever.
--
pyotr filipivich
Next month's Panel: Graft - Boon or blessing?