Somebody mentioned the molasses treatment for steel. There are lots of YouTube videos with car parts sitting for weeks in fermenting tanks of molasses and water, 1:10. I dismissed it, as I sure as hell am not going to turn the insides of Seeker into a fermentation tank. But then I found a bottle of molasses in the pantry today. Hmmm, so lets see what smearing it onto the steel does. At least until the rain washes it away.
All this is because we are seriously looking for a path that avoids sandblasting the interior of the boat. That would be a horrible job. And now that we have it on good advice that modern paints like POR 15 can deal with light rust without blasting we are hopeful. The trick is to remove as much of the rust as possible. Hence the molasses test. And I am not going to put this anywhere inside the boat till I can see that it works to some degree on the outside. This stuff stinks. And it’s not even started to ferment yet. But the dogs like it. What they don’t lick it off they let it dip into their hair before coming back inside the house.
Apparently molasses contains a small amount of phosphoric acid, and phosphoric acid is commonly used to clean rust. But the amount of phosphoric acid is also dependent on the production process, so it may depend on the batch. However it might be that adding phosphoric acid to molasses would work better than just spraying phosphoric acid on, as it would hold the acid in contact with the vertical steel.
Here is the main post about PAINT. Recommendations and suggestions are welcomed.