Trailer Hitch -- '04 XC70

Post by **E Showell** » 17 Feb 2020, 08:05

So, I picked up a used Volvo trailer hitch and wiring harness for Ruby Red. The tow bar has a bit of surface rust. Current plan is to remove scale with a wire wheel, wipe down with acetone, Rustoleum rattle can primer followed by Rustoleum gloss black. Treat afterwards with Fluid Film as rust protectant. Sound reasonable?

If not, what should I do differently?

Post by **E Showell** » 17 Feb 2020, 12:11

Changed to 80 grit sandpaper on a random orbital sander. May go to 60 grit.

Post by **- Pete -** » 17 Feb 2020, 16:59

I had the towbar off our V70 AWD blasted & powdercoated for $65 I think it was. I have access to a big blast cabinet but for $65 I've got much better things to waste time on. They come powdercoated originally. I fear you will see rust fairly soon with rattle can. In MN we have to replace license plates at 7-year intervals because they rot out from salt exposure. I welded a receiver hitch cargo carrier & painstakingly primed & painted it. I bet I had at least a dozen empty cans, if not more. Rust still showed up very quickly, maybe a week or two.

This was prior to last winter & the car gets driven daily in the salt & slush up here. Still looks just as good as it did when I re-installed it.

Post by **E Showell** » 18 Feb 2020, 14:28

Will sand to no rust visible, treat with some form of phosphoric acid solution to convert any remaining oxidation to zinc (or so I am told -- where's a good chemist when you need one?) Then rattle can primer with gloss over followed by fluid film. I am told Fluid Film is the next miracle cure. We'll see.

Post by **abscate** » 18 Feb 2020, 14:33

E Showell wrote: 18 Feb 2020, 14:28 Will sand to no rust visible, treat with some form of phosphoric acid solution to convert any remaining oxidation to zinc (or so I am told -- where's a good chemist when you need one?) Then rattle can primer with gloss over followed by fluid film. I am told Fluid Film is the next miracle cure. We'll see.

That would be a good paper, Fe----> Zn plus some energy I bet.

The rust converters haul the Oxygen away from the Iron, stick it onto the Phosphorus, then bind it up leaving a relatively inert

FePO4 instead of crumbly Fe2O3

Post by **E Showell** » 18 Feb 2020, 16:43

So, before I do any more sanding, I may try rust removal with white vinegar and salt. Any spare solution I can use on my fish and chips (although malted vinegar would be better).

Post by **E Showell** » 18 Feb 2020, 19:38

So, ferric phosphate as opposed to ferrous oxide, eh.