Rust prevention questions

Guys. I am not a paint and body guy so I figured I would post my question here. I have a 1992 M101a2 in very good condition. VSE corp reconditioned the trailer in 2007. It has no known rust and the CARC (Painted in 2007) is in very good shape. I live in Michigan and this trailer will see its fair share of logging roads, mud, dirt, rocks and salted winter roads. I want to do as much as I can to protect what I have.

I am in the process of completely disassembling the trailer and want to coat the chassis, wheel wells, and underside of the bed with a very tough coating. I have head a lot about POR 15 and Chassis saver. While the trailer is apart, should I coat the frame and underside of bed with one of these products? If so, can I paint it right over the existing CARC paint with a simple powerwashing and cleaning? Both the chassis saver and POR 15 claim that they will not stick to bare metal. What about Bed liner? If I prepped the frame (scuffed it down) would that work as a tough under coating/rust preventative? I want something that will last a few years.. I dont want to have problems with peeling paint, flaking or whatever in a year or two.

Any recommendations, advice, experiences etc would be greatly appreciated. I already have two quarts of chassis saver that was going to be used on another project...

What do you think?

Thanks,
Jeff

Zincs.... just like a saltwater boat. Rusty metal primer over cleaned and prepped bare steel (if you take it down that far.) and a good quality paint over the top. Google cathodic protection. Same physics as galvanization.

Heath_h49008 said:

Zincs.... just like a saltwater boat. Rusty metal primer over cleaned and prepped bare steel (if you take it down that far.) and a good quality paint over the top. Google cathodic protection. Same physics as galvanization.

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I'm wondering how that "brush on" undercoating available from AutoZone/CarQuest etc., would work.
Don't know how it would hold up if ya just brushed it over a good coat of CARC.

We don't use/need salt here in SW GA but I remember in KY they salted the roads heavily at times...ate the crap out of anything metal!

I know the M49A2C I got from Fort Knox has a few rust bubbles coming up under the CARC.
Don't know if that's from snow/salt etc., or just poor prep before painting the CARC on.
Gonna have it blasted eventually I guess.

I'm not familiar with Chasis Saver but POR 15 is supposed to be applied over bare metal only. It needs to be degreased and prepped with an acid wash, either their Metal Prep or I use phosporic acid like they use to clean grout off of ceramic tile. POR 15 won't stick to any paint.

X2. Using POR over paint is just paying too much for paint. POR only works on bare metal, and in fact likes rusty metal the best. That is why it is called POR (paint over rust) and not POP (paint over paint).

POR works a lot like super glue. It needs moisture to cure. The moisture is what is already in the bare, rusty metal. It sucks this moisture out and cures. But it has one other trick up its sleeve. It also forms a barrier impermeable to water. So no new moisture can get to the metal. So the metal does not rust any more, and no new rust forms. It does this quite well, except any grease or oil on the bare, rusty metal is a problem.

You can topcoat POR but you do it while the POR is still tacky.

The moisture in the air is enough to get POR to kick, and that is why you never open a can of POR. You poke a hole in the top, dribble what you need out, and seal the hole with masking tape. When you need more, you repoke the hole, etc., etc. Doing it this way gives you years of shelf life because moisture (humidity) never gets into the can.

There is absolutely no reason to ever apply POR over existing paint.

Ok.....heres my 2 solutions to this...

1) get a gallon of bedliner and coat it like you mean it. 2 coats will do wonders, let it cure in full sunlight for 5 days straight.

OR go redneck and mix some roofing tar, used motor oil, bar and chain oil (chainsaw) and coat it while together, and then drive down the DUSTIEST road you can find. Itll coat on like mud on a boot. and to take it off, get some industrial degreaser, and a steam cleaner of hot water pressure washer. thats how we do it in MN

Thanks for the responses. Yeah, because the CARC is in such good shape, I would hate to have to sandblast the entire Chassis and bottom of the bed to take it to bare metal. I dont own a sandblaster and to have it done by someone would be too much $$$.

To sum everything up, I guess I am looking for the best method/coating to "Prevent" further rust and issues down the road. As I said, I will be using this trailer for everything from deer camp to winter hauling on salty roads. Here in MI, we use A LOT of salt. The CARC that is currently on the trailer is in good shape but seems to scratch easily showing bare metal or a white primer that was used by the military.

So if I DONT take the thing down to bare metal, what do you guys suggest? Two party epoxy primer over the CARC and then paint? I want something tough that I am not going to have to worry about in 6 months or after salty winter driving.

I appreciate it.
Jeff

I vote some Hurculiner (Bedliner). Its made to take a beating, and resists stains (salt, roadmelt, etc...) AND its pretty cheap insurance against rust. And whatever you have left, can be used inside the box.

True CARC is a urethane, like Imron, and should be able to take alot of abuse. One of the many reasons Uncle chose it origionally

Yeah I was thinking bed liner as well. Again, just not sure how much prep I would have to do to the original CARC to make the bed liner stick and stay.

Regarding the CARC as a urethane... I will say that it is tough but it does scratch rather easily from my experience. Any thing sharp (metal etc) will take the Carc and primer right off. Need something tougher.

I am going to search the site for threads where someone used bed liner.... see what I can find.

Thanks Jeff

Painted surfaces do not rust. If it's got a good coat of paint on it, you should be good to go.
Touch up any scrapes / scratches every summer.
Or throw money at covering it with something else and touch that up every summer.

as already said POR15 will not stick to anything but bare metal.

Does it have to be green? If so, you are looking at more topcoat.

Can it be black? Then I am partial to POC (plain old undercoating). Touch up any bare metal or rust with rusty metal primer and some top coat. Then hit it with POC. It is flexible, spot damage can be repaired (unlike bed liner), and it is cheap. You can get four quarts of undercoating and a gun to apply it from several places on the Internet, or use spray bombs from NAPA.

Every spring, hose it down with hot water. Touch up any problem areas (there will likely be none). It will last another 100 years.

I spent time on the crud crew (corrosion control) while in the Marine Corps. We had to take a corrosion prevention course while running the marathon of schools to get quaified on various aircraft. Simple reason...salt water. Lesson learned goes something like this and somewhere i still have my book.

Metal, when the initial coating applied by the manufacturer has been removed, comes in contact with a corrosive element, corrodes. Once corrosion has begun, it has to be stopped immediately. The way to do that can be done at least two ways. Easy way, scrape off the worst of the corrosion, hit it with some Rustoleum Rusty metal primer. Then top coat it with some Krylon Ultra Flat spray paint. I painted my tan truck using this method. There wasn't much rust and the Rustoleum and Krylon set well. I haven't had to do any touch up because of corrosion and I painted it a year ago. If you have heavy corrosion, the following may help you. If there is no corrosion evidence, leave the top coat alone. If it's CARC, Krylon Ultra Flat sticks just fine. You could do other top coats, I'm just pointing out the materials i used.

The best option for corroded metal is to strip the metal bare, etch it with a commercial product and prime it with a quality primer. Then paint it with a top coat that is compatible with the primer. After that, keep it clean and constantly inspect it for chips or other imperfections in the paint. Immediately clean and redo all steps listed above for those areas. In a corrosive environment, you have to constantly inspect and treat the corrosion as soon as it appears. The #1 preventative is rinse with fresh water immdiately after coming in contact with a corrosive environment.

Sounds like a lot of work but if you invest a lot into your equipment/trucks/trailers in the long run you'll save money on repairs or worse, replacements.

That's the Navy School answer (Aviation Marines went and still go to Navy Schools). One thing to remember: whatever you put on the metal, if corrosion starts, you have to remove it. If you have a coating of under coat or some similar heavy coating and it starts bubbling from corrosion, you have to get that coating off so you can retreat the corrosion. That's the reason I never undercoat any vehicle I own. Fresh water and lots of it is the best method to prevent corrosion from ever forming. That's my 2 dollar answer, hope something in there helps.

You may have a problem with that "white primer" underneath the CARC. My 8606 has that and I couldn't figure why there was a white undercoat on my Marine forklift painted with CARC. I eventually found out it was a latex primer. The problem is it pops off in quarter sized spots randomly all over down to bare metal. I've been hitting the spots as soon as they flash rust with POR 15 which turns my forklift into a camo Lepard. I suspect eventually it will peel all over if I don't sand blast it and paint it first. Right now I'm just fighting a holding action untill I get caught up with other projects.

wdbtchr said:

You may have a problem with that "white primer" underneath the CARC. My 8606 has that and I couldn't figure why there was a white undercoat on my Marine forklift painted with CARC. I eventually found out it was a latex primer. The problem is it pops off in quarter sized spots randomly all over down to bare metal. I've been hitting the spots as soon as they flash rust with POR 15 which turns my forklift into a camo Lepard. I suspect eventually it will peel all over if I don't sand blast it and paint it first. Right now I'm just fighting a holding action untill I get caught up with other projects.

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That is exactly what I have heard and exactly what I am afraid of. I really dont want to have to pay someone to blast the thing down to bare metal. That would be way too much $$$$ and would just plain suck!

My understanding is the the white primer is used under the newer CARC. Has anyone else heard this? The old CARC used a red or yellow color primer. I have also read that if the new CARC was used on my VSE refurbished trailer in 2007, it should be stenciled with "WD CARC" however mine is stenciled with just plain "CARC" on the frame wiring harness junction cover. I am confused.

I am also reading up on aircraft stripper to remove CARC.... Not sure what I should do now...

1) Scuff the existing CARC (which is in good condition), paint the bed with bedliner, paint the exterior of the trailer with whatever, and be done with it... OR

2) Media blast the entire thing, clean, prime then paint? Or

3) Use stripper and try and strip all the CARC and white primer, clean, prime and paint...

I want a nice trailer that is protected from the elements yet I dont want to spend a fortune. At the very least I need a roll in/spray in bedliner.

I am going to PM "Nonotagain" as he seems like he knows alot about the mil paint process from past threads I have read.

We will see.. again, I am open to opinions.
Thanks
Jeff

michigan4x4,
Just be careful when using chemical strippers. If they are left on too long or the surface isn't promptly/properly cleaned it can get into the metal and cause issues with paint adhesion. My best advice is to do small sections that you can finish the stripping and post strip cleaning on in a timely fashion.

VSE uses good primer under the CARC. I would not mess with it. Just wash the salt off real good in the winter months. You can scotchbrite the CARC and apply bedliner or undercoating. If the trailers last 20 to 30 years for the goverment I dont think you have any thing to worry about.

At the risk of starting a "Gibbs is awesome/Gibbs sucks" digression, a couple of years ago I finally used up the one can of Gibbs I had and I called the 800 number on the label (this was a really, really old can of Gibbs). The number was answered by some other company that used to distribute Gibbs, but they had a disagreement so this company went out on their own with their own formulation, which they said was better the Gibbs. The price was right and I bought a couple of cans, and it really was good. But I digress -- this same company sold aerosol cans of rust protector. It was a thick waxy substance heavy in lanolin. Sprayed it on, the vehicle evaporated, and this thich white protectant stayed behind. You apply it over anything - paint, primer, bare metal, rusty metal, whatever - and it shields from additional rust. It is easily renewed when needed, and one can went a long way (I bought two). The only downside was that because of the heavy lanolin, it did smeel a bit like sheep, but that goes away in a day or two.

I used it on some vehicles that saw use in areas with very aggressive winter salt programs and it did its job.

This might be exactly what you need.

The product seemed a lot like Waxoyl, which is sold in the UK but not over here, in that it left a resilient waxy finish behind. I don't know if Waxoyl uses lanolin, though.

I ran out of that stuff and I don't think I saved the empty cans. However, I once was going to mix up my own. I bought a pound of lanolin and I was going to mix it with a vehicle, mineral spirits or lacquer thinner or something, in an attempt to achieve the same thing. Have not done it yet, though.

plym49 said:

The product seemed a lot like Waxoyl, which is sold in the UK but not over here,

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The line up of their products are good, but expensive. It is available here in the US for "professional" use only. I know of a state side source if you ever need some.