Rust treatments/prevention structural steel

[Raisedonadeere]

Mobile home rails are beginning to rust. I see products called rust encapsulators, Rust-Oleum has one, - - and also, I have come across Eastwood, Por-15 and Xion Lab 2 in 1 converter. What I read makes me think it might be helpful.



Two questions
- Do any of you with experience with these rust encapsulator products such as Eastwood, Por-15with etc., have any wisdom you could share?
- Do any of you know of a better place than here to pursue this particular question about rust encapulators?

 

[Danno1]

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Rust-oleum rust reformer has worked well for me on motor vehicle frames driven in the northeast winters (read road salt).


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[bluedog225]

Is it fixed in place? Old school, smear it with grease. Or spray motor oil regularly.

 

[Beerhippie]

A rust "encapsulator" will do just that: ecapsulate rust. The rust is still there and unless you're 100% sure it's absolutely isolated from air, will continue to rust--out of sight. Chances of 100% isolating the rust patch from air makes the odds of an icecream cone in hell look pretty good.

You need to get rid of all the rust--chemically or mechanically--then use a good rust preventing paint or primer. Red oxide primer is my favorite for this.

 

[AC-WC]

POR-15 is well known for rust encapsulation in the automotive restoration market. As long as the metal has no rust flakes and reasonably clean It will work wonders. You can wire brush the flakes and it will work just as good. Especially underneath where it will never see UV light. POR has an open canister shelf life meaning once you open the can you have to use all of it. It does not store well once opened.
I've had surprising good luck with rustoleum rust reformer too. I did the underneath of my wife's 2012 and 2 yrs later it was still in good shape and did not need redone in northeast Indiana.

 

[Youngandfree]

Corroseal is another one that can be topcoated with no special primer.

 

[racecougar]

You could hose it down with Fluid Film or Woolwax, too.

 

[Raisedonadeere]

Thanks for confirming that these products are not 100% snake oil. My limited experience told me those claims were pure scam. But the reviews seemed encouraging that there was a place for those products. Getting the scaled rust sufficiently removed is probably going to be my Achilles heel. It comes off easily but so many surfaces make it time consuming. I suppose my next move will be to come up with the best tool, probably various scrapers, and do 10 feed and come up with a time estimate for rust removal.

AC-WC, concerning the time after opening the POR-15, are we talking about limited to one or two days to work with, or just a few hours?

 

[4x4Pete]

Por-15 will last up maybe a week once opened. I would consider spraying with oil undercoat, it'll be much less expensive.

 

[Beerhippie]

For the rust removal, consider a needle gun. Slow, loud, less work and more effective than scraping.

 

[lund]

Coating over rust only helps marginally. Oxygen and moisture gets locked in under the paint and rust continues. It can be better than nothing to paint over (slows down isofar and seal on surface is not broken by blistering paint and is non-permeable enough). But you really need to scrape, wire brush, and/or surface grind out before painting with a good quality primer/paint to arrest it.

You can watch youtube vidoes on fixing car underbody rust to get an idea. Cars are much harder since road grit spray damages the paint. But the same products and methods will work for you. I suspect the beams on a mobile home might be more accessible than the many truck underbody nooks and crannies. If you prep well, Rustoleum or many other paints should be fine. Fluid film type products are good too and should work even better in this context.

 

[Raisedonadeere]

Thanks everyone. Another consideration would be . - - do any of these products create an even worse problem years later once it has gotten old?

 

[LopezBart]

One approach that isn't expensive, and lasts a long time:

Wire brush off loose material. Apply phosphoric acid ("Ospho" or "Metal-Prep") and rinse according to directions. Prime with Rustoleum Rusty Metal Primer. Finish with Rustoleum enamel.

If one is building something new from steel in a rust prone environment that has to last, very little beats hot-dip galvanizing. The seat brackets on my parent's deck were welded and then hot-dipped, and are flawless 40+ years later.

 

[Beerhippie]

One approach that isn't expensive, and lasts a long time:

Wire brush off loose material. Apply phosphoric acid ("Ospho" or "Metal-Prep") and rinse according to directions. Prime with Rustoleum Rusty Metal Primer. Finish with Rustoleum enamel.

If one is building something new from steel in a rust prone environment that has to last, very little beats hot-dip galvanizing. The seat brackets on my parent's deck were welded and then hot-dipped, and are flawless 40+ years later.

I'd add one thing to the use of phosphoric acid rust removers: DO NOT RINSE! Left to air dry, you have a nice iron phosphate base for your paint or primer.

 

[racecougar]

Thanks everyone. Another consideration would be . - - do any of these products create an even worse problem years later once it has gotten old?

If the product encapsulates the rust but allows the rust to continue (rubberized undercoating for instance), absolutely. Again, for the purpose you're after here, I'd Fluid film or Woolwax it. You don't have to spend any time removing rust ahead of time, just spray it down with FF or WW.

 

[Raisedonadeere]

I learned all about the folly of rubberized coatings back in the 60's. Lots of scams doing cosmetic undercoating of cars to prevent rust, and then finding out that even a good job only stood a decent chance of working if applied to an absolutely pristine new car.

This has been a great review for me. I am going to take a shot at cleaning up and coating with encapsulater but i predict that the labor required will just be too much in which case I will take the Woolwax approach.

I am hoping Woolwax is a bit more robust than Fluid film. I use fluid film around farm machinery for lubricity retention and am always a bit disappointed it doesnt last longer. Perhaps in a crawl space it will last longer.

 

[Raisedonadeere]

Seems woolwax is a spray application. I have never done much spraying other than rattle can stuff and a fence once. What gun do I need and how much air compressor, if I am spraying maybe 50% of the time in 5 or 10 second bursts.

Is there an electrical gun that would work? All I see mentioned is undercoating gun.

My old Craftsman 10 gallon is on it's last legs. Still running the belt that came on it in 1965

 

[E1271]

Seems woolwax is a spray application. I have never done much spraying other than rattle can stuff and a fence once. What gun do I need and how much air compressor, if I am spraying maybe 50% of the time in 5 or 10 second bursts.

Is there an electrical gun that would work? All I see mentioned is undercoating gun.

My old Craftsman 10 gallon is on it's last legs. Still running the belt that came on it in 1965

Woolwax is a great product, it is thicker than fluid film. They sell a kit that includes the sprayer. Get some extra bottles, 1 for each day. They can be cleaned and reused but its a mess.

Get a painters onesie and a decent respirator.

 

[racecougar]

Seems woolwax is a spray application. I have never done much spraying other than rattle can stuff and a fence once. What gun do I need and how much air compressor, if I am spraying maybe 50% of the time in 5 or 10 second bursts.

Is there an electrical gun that would work? All I see mentioned is undercoating gun.

My old Craftsman 10 gallon is on it's last legs. Still running the belt that came on it in 1965

I use a Schutz gun for both FF and WW. I bet a 10 gallon compressor would get it done; my 60 gallon is not taxed whatsoever when spraying either one.

How were you applying FF on the farm machinery you mentioned? It lasts quite well on vehicles when sprayed on with a Schutz gun, notably better than aerosol.

 

[LopezBart]

I'd add one thing to the use of phosphoric acid rust removers: DO NOT RINSE! Left to air dry, you have a nice iron phosphate base for your paint or primer.

I let them dry completely, and then rinse off any remaining white loose powder. This seems to work well; one can also just lightly brush off the remaining loose powder. Iron (both ferrous and ferric) phosphate is practically insoluble in water.

 

[Raisedonadeere]

I just use aerosol for the Fluid Film. And not so much for rust but to make hitch pins and various linkages easier to work with than the normal dry bare metal use. It does make the day go better.
I don't deal much with rust prevention although there are surfaces I should be using to make the ground engaging stuff go better next time out.

The surface coating stays well and prevents rust, but the lubrication part does not last as long as I would like. But it does better than slopping things up with oil or grease and far less messy so I use it.

 

[Hank11]

Any oil, grease or wax will be a dirty mess after a few years of dust settles on it - but that may not matter in your situation.

 

[racecougar]

Right. My understanding from the OP is that this is the underside of a mobile home. Hose that sucker down with FF or WW and call it a day. It doesn't need to be pretty; it just needs to not rust.