i have a bolt on hitch for my 1997 impreza. looks solid, but all the black is flaking/peeling off and it has surface rust.

 

what's my best option? is powdercoating overkill and not necessary? what kind of primer paint combo would hold up to this if i wire brushed and painted it? i used some cans of rustoleum on stuff before and it chipped off fairly easily.

 

am i being too picky?

Yes, you are being too picky.

 

However the best solution for rust, IMO, is sandblasting then treatment with a POR-15 type product.

 

What people don't seem to have yet learned about rust is that the visible rust is just the surface. Steel is a porous material, and oxidation occurs quite far into the metal. If you are interested in detailed metallurgy, start with the term 'passivating', you will learn quite a bit.

 

Sandblasting give quite good results, if you have to proper setup (lots of airpressure and volume and room to work), and wastes less steel than grinding.

 

The little hand-held sandblaster guns work well for the price, but for any large piece, it pays to have it done by a real sandblasting shop.

 

Any time I spot treat a rust spot, my normal procedure is sandblast, then treat with POR, then fill,sand, and finish.

 

 

 

i have a bolt on hitch for my 1997 impreza. looks solid, but all the black is flaking/peeling off and it has surface rust.

 

what's my best option? is powdercoating overkill and not necessary? what kind of primer paint combo would hold up to this if i wire brushed and painted it? i used some cans of rustoleum on stuff before and it chipped off fairly easily.

 

am i being too picky?

you could take a page from the motorcycle guys and use stove polish to finish it. Easily touched up, probably a pain if you blast it though. Might work if you use grit thats already been through the blaster once or twice.

Sometime back I saw a commercial or infomercial about a product that supposedly chemically changes the rust into an enert black coating, then you paint over it or coat over it with whatever. Probably been around forever. Can anyone chime in if they are familiar with the product I'm talking about and is it worth it?

 

I can't remember much about it right now. I'll have to web search latter.

3M made a product like that...I tried it many times to no long term avail. It always rusted underneath the plastic coating. I have to agree 100% with uniberp. Working on vehicles since the mid 60's the only real way to correct rust was cut it out and put in a better steel. But in your case, I wouldn't spend too much on it since a replacement hitch is $100 or less. You might spend more than that on trying to save this one.

 

I would sand or blast it and try a rust resistant paint first. That should last for a while.

Yah if you can blast all the rust off in some manner, harbor freight always has sandblasting equipment on sale but as mentioned you need a good compressor and connection. They have the little handheld guns on sale all the time, some people just use sugar or baking soda in them for blasting, never tried that though. The POR-15 sounds like a great idea I've hard good things about it, just make sure you top coat it afterward or it'll get distorted a little from the sunlight.

What uniberp said. I have used POR15 and it works well if you intend to repaint. If you just want to stop the rust and aren't worried about looks, use some par-al-ketone thinned with mineral spirits and a spray bottle: http://www.aircraftspruce.com/catalog/appages/paralketone.php

That'd be scrap metal out here. Id be concerned with safety in towing something that rusty but using it for a bike rack would be ok. Find somebody that will sandblast it and have them primer it as well then paint it yourself. If you dont have them primer it...it rusts on the way home.

but using it for a bike rack would be ok.

that's the only thing it may ever see, and that will happen rarely. the XT6 and Ford Truck do all the hitch work.

FWIW, Por-15 likes to be applied directly to a rusty surface (remove loose scales though). if you blast you need to use por's metal ready before applying.

I recently switched from POR-15 and tried two different products, as follows:

 

Rust Bullet http://www.rustbullet.com/

Masterseries http://www.nomorerust.com/

 

Both products are similar in that they are a moisture curing urethane material, but they are also much heavier, easier to apply, and I feel it will be more durable.

 

Jack