I just finished welding floor and chassis pieces of Morris Minor on a rotisserie, and it’s been about a year since I started. We get about 11 inches of precipitation here, so I don’t see any new rust. I have a great sand blaster I’m ready to use on the remaining old rust just before I epoxy primer the floor. I read “how to prep for paint from bare metal”, above. The floor has a lot of plug welds, butt welds, dimples. My question is, since so much of the metal has been bare for so long is there anything I should do to remove any invisible rust? And is invisible rust even an issue when using epoxy primer? I’m going to use a good grey primer and black single stage paint and am not concerned about the appearance at all, just want to stop as much rust as I can. Thanks

I would use the media blaster to remove the rust like you planned but then lightly hit the remaining floor as well.
The media will prep the floor just fine for epoxy primer.

Thanks, Ill do that. Was considering it but thought it might be overkill

remember you can brush or roll it on also, sometimes its easier in a situation like yours.
Jay D.

Thanks Jay, I’ve heard it’s ok, wasn’t sure. Seems like a fine brush might work it into small cracks and cavities better too