[oysterbreath]

What's the best way to rid a galv trailer of rust and to prevent further rust.

My current plan is to wire brush the rust from a trailer, preform the proper prep-work then apply a high zinc primer.

There are other methods but I don't know them.
In fact...I don't know much about this at all. Recently, I ran across Soda blasting as an alternative to wire brushing. Anyone done this? Harbor freight has some cheap soda blasters. Is this method worth the investment?

Also, any economical alternative to high zinc primer?

Rustoleum STOPS RUST Cold Galvanizing Compound Spray?

PlastiKote 471 Zinc Rich Primer Enamel?

Black Star Rust Converter?

Anyone used these?

Thanks

 

[Brett]

Rust removal from old steel, oh the memories.
Used to work on an old steel ketch, many hours of chipping and grinning.
Heavy rust deposits required a chipping hammer to break it loose.
Then a heavy wire wheel on a commercial grinder to get down to clean metal.
Followed by primer and bottom paint. The good old days.

Same holds for trailers. Chip, wire brush, and sealant.
I have used the spray galvanizing, it does work, for non-submersible trailers.

 

[DuckNut]

Blasting is so much easier than wire brush- but you can ruin metal if spend too much time in one area. The clean up is the problem.

POR paint is an incredibly tough paint. A buddy who builds trailers only uses it and is a staple in the military.

 

[oysterbreath]

Ahhhh Brett and Ducknut; the big dogs have chimed in!

Well, I have everything I need for wire brushing. If I blast then I will need to buy, borrow, or buy it and CLAIM that I stole it! lol

So duck, Are you referring to sand or soda blasting?
I have heard a wee bit about por. Mostly that you have to be very exact with it...

 

[DuckNut]

Oyster, my computer decided to lock me out. I will reply when I get back in.

 

[David_Estes]

Don't waste you time with soda..... much toooooo fine.. sand blast is the way to go... How ever if to remove the flaky then wire brush. Treat the bare spot with Aspheric acid. Tons of brand names (SKYCO OSPHO) and wash with lots of water, Force dry (compressed air and a heat gun) Give it several coats of cold galvanize, you should be good for a season or two.

FYI works great for removing the water scum line on light color gel coats!!!!!

 

[DuckNut]

Blasting with anything will cause heat to he metal. The cleanup is a mess unless you can do it in a place you can just leave it.

POR is pretty fussy but that stuff is tough.

Blasting is the best way. Check your local Sunbelt rental, they may have one to rent (compressor and blast tank).

 

[Recidivists]

Don't waste you time with soda..... much toooooo fine.. sand blast is the way to go... How ever if to remove the flaky then wire brush. Treat the bare spot with Aspheric acid. Tons of brand names (SKYCO OSPHO) and wash with lots of water, Force dry (compressed air and a heat gun) Give it several coats of cold galvanize, you should be good for a season or two.

FYI works great for removing the water scum line on light color gel coats!!!!!

Phosphoric acid is the ingredient.  Osphos, Naval jelly, and POR all have it.  Converts iron oxide to ferric phosphate, the black substrate you end up with.  You may then scrape or brush off that, or coat it.  Removing as much caked on rust is best.  If you can convert whatever much thin skin is left without blasting, then you should be cool for a few years with a good layer of galvanized paint. The key is not allowing water to get to an exposed layer.

It all depends on how compromised the steel is. Are there weld joints that have holes in them?

Oxalic acid is great for removing rust stains and wax.