Rust!! How to deal with it??

Jake

Ospho is good stuff. I usually apply it with as squirt/spray bottle like you buy in lawn and garden places. Don't set it to a fine spray and you don't have to yank on the trigger so hard as to create a mist. Just spritz it on.

I cannot find ospho anymore so I was able to get the same stuff at home depot in a gallon. it is usually called bare metal prep. All that metal prep stuff is basically phosphoric acid. it converts iron oxide to iron phosphate.

Anyhow you have to get yourself protected also.

Don't use it over a concrete floor, since any drips will immediately start eating the concrete.

If just hoping for a few more years, I'd forgo the sandblaster expense and effort.

Knock off the loose flaky rust with a wire brush then apply the Ospho twice. While the rust may turn black within an hour or 2, depending on temperature, do wait the full 24 hours before painting, and make sure it does not get moisture on it in that time.

Rattle can is a waste of money for such a surface. Brush/ roll on something, in several coats with adequate dry time between coats. I've used the Rustoleum marine/yacht enamel and it is a much better product than their regular offerings when applied correctly( not too thick, in one coat). It adheres better to the substrate and dries harder. Half the price of Interlux yacht enamels, and a smaller fraction of POR15 or rustbullet prices.

Thanks for the great responses, I do want to buy a sand blaster and give it a go.
Oshpo sounds like a good product. I will blast what I can get at and use the Oshpo and slop it on. If I can get a few years use before the rust comes back I will be happy.
Rust is not to bad,, still has paint on the fenders,, nothing rusted through, so I am sure a bit of elbow grease and a fresh rattle can paint job will get me out crabbing in November...

I restored cars for several yrs. The salt water is a big issue but I know that as said before POR 15 is the only product that will stop the rust from progressing. Blast it, clean it then treat with POR 15. I always got it from Eastwood Products.

+1 on the Oshpo.

Do not have to expend super amounts of effort removing rust.

It is very thin and gets deeply into the nooks and crannies. I have applied it with a brass brush 24 hours apart on badly rusted surfaces, sometimes the second attempt shows grey pitted steel where flaky rust existed previously.

Do not let it get wet or moisture to condense on it for 24 hours after application.

Paint sticks to it great and it must be painted

I am highly doubtful about rustoleum's ability to slow, treat, prevent rust.

Rust bullet and Por15 are $$$. Do not know how much better they are, but I suspect a couple hundred percent.

How much is a new trailer versus the time/effort and materials to slow the rust on what you have?

I'd inspect the worst, most structural parts first to see if they are structurally deficient and not worth the effort, unless you happen to have a welder and stock handy and the skills to re-enforce.

For steel, blasting is the best for heavy rust as it gets the smallest bits of rust out of the metal. If there is just light surface rust, wire brushing with a right angle grinder and sanding with DA, followed by an acid etch will result in a pretty good paint job.

For acid etching: I started with Martin-Senour auto body products, expensive but very effective. As my needs increased and economy became important, I started using liquid water softener treatment, a handy source of phosphoric acid and 1/3 the price. Now, I stop by my local reuse and recycle center and pick up cast off dehumidifier descaler and any other phosphoric acid in a bottle, for free. After mechanical rust removal, the acid is applied to the metal and allowed to work overnight. A very dilute mixture of acid and water is brushed for the first rinse. Water is then used for a final rinse. You could always break out the wife's CLR tile cleaner and try a few experiments, it is also PHO4 based (unless they've nerfed it).

I highly recommend Sherwin-Williams DTM Industrial primer for trailers. It has excellent bond and barrier characteristics.

School Of Hardest Knocks Dept...

RUST CONVERTERS, liquids you slop on and they turn black, work great BUT, and yet another BUT...

Fenders and brackets have to come off, breaking bolts in the process or no.

The rust converter has to coat EVERYTHING like a bio hazard suit.

This can be a problem accessing areas beneath crossmembers and forward near the hitch.

What happens in incomplete "conversion" (rusty holidays)is that untouched rust happily digs it way UNDER treated areas and keeps on eating. The converted rust and new paint falls off in patches.

That Rustoleum pain-over works very well ... I've wire-brushed some metal items in the past (not a boat) and it made me a happy camper. Cape Cod means seas and salt air. But the items (tools and metal patio furniture) held up well over the years.

Lot of work, but worth the effort if you can use the boat for a few years at least.

I have used OSPHO on salt water items with success. ( You can generally get it at ACE hardware or marine places.) Wire brush the loose stuff, paint or spray it on ( its the consistency of water) then after it dries, paint it with a good exterior oil based enamel paint. You should be able to get some more use out of the trailer. Be sure to check weld areas as they are prone to failure/rust. Also, make sure your wheel bearings are serviced.

You are starting off on a battle you will eventually lose. There are areas of the trailer that you cannot get to in order to grind or sand blast(i.e. inside the tubes that form the rails) Cut your expenses and get a galvanized trailer if you intend to continue to use this outfit. Not what you wanted to hear I know, but if this thing was submerged in salt water often it will rust and there is little that can be done to stop it - slow it down? maybe but that will be only on surface that is visible