There is a potential cosmetic restoration a few volunteers and I are looking at on a locomotive that is currently sitting rusting away but has been evaluated by someone with experience with such things as a very good candidate for operational restoration. We do not currently have the funds nor the volunteer power to do that, nor do we have the funds to cover the locomotive, but at the same time we don't want to see this thing continue to deteriorate to the point where operational restoration is even more expensive or impossible. Some of the thinner (easily-replaced) sheet metal on it has already rusted through - not badly but it is becoming a concern. So the solution came up to use a rust converter and a coat of Rust-Oleum to at least keep the oxygen and moisture out of it until someone can do a proper restoration (on the outside, specifically on the most weather-unprotected side). Most of the rust is fairly hard and is holding its structure well. Despite being outside unprotected for decades, the rust doesn't seem to have penetrated far and (at least to the untrained eye) most components look like if you could get the surface rust off and lubricate it, it'd probably run. Even most of the very thin sheet metal has no holes - it's just in a few spots where there has been an excessive water buildup from being out in the elements. The locomotive has been moved in the last few years, so the journals do still work okay.

So, my questions are:

1. Are there any drawbacks to this plan for a long-term possibility of an operational restoration?

2. Is there anything we should be doing to prep it outside of knocking loose rust and paint off beforehand?

3. Do we need to anything to protect the journals or other components (cylinder saddle, air pumps, etc.), or is it okay if rust converter gets into things while applying it?

Although I have quite a bit of experience with paint (indeed, it's the task I'm most known for at this railroad), I have zero experience with using a rust converter, so I am a total newbie to this concept. I don't even know what brand or type of rust converter is currently being procured (another volunteer who is more familiar with it is handling that part). Hence the probably very obvious questions. Considering that rust converter converts rust, I would naively assume most of my concerns are not merited, since otherwise it would be rust anyway and it's not going affect the underlying good structural metal, but I thought it better to confirm that before diving headlong into a large project like this.

Any advice?

Rust converter does indeed convert rust into a coating that will help protect the underlying metal against further rusting, and provides a good surface on which to apply cover coats of paint.

Loose rust and dirt must be removed for maximum benefit.

It won't harm the good metal under the rusty layer, which isn't going to do you any harm either as far as mechanical stability is concerned.

I'd want to cut and patch any sheet metal repairs in place before treating and painting.

It is almost never a good idea to get stuff down into mechanical assemblies that isn't supposed to be there. I cringe whanever I hear about somebody being proud of sandblasting....which just sends abrasives under pressure into bearing surfaces. If there are rusty parts inside, and they are converted, they might well bond during conversion and be a bit more difficult to seperate during a restoration, so.........try not to get it down your air pump, journals, etc. They can be treated with lubricating preservatives like Cosmolene or heavy grease, but be prepared to occasionally go back and wipe down and replace the stuff.

Sounds like you're taking a very sensible approach and have figured out the likely problems on your own. Good luck.

dave

Me, too. Another volunteer this weekend wanted to sandblast it. He figured, eh, it's currently stationary, what harm could it do. I then explained said harm and what it could do, as well as some alternatives. I wish some of that stuff was a little better known. Reading case studies of restorations on here for the past few years has been incredibly valuable in that regard.



Good to know. With that being the case, I'll probably see if we can just coat them with paint. Probably won't hold up as well, but at least with that we can largely get it back off. Part of the point of this is to eliminate the need for the upkeep that it's not getting, so unfortunately wiping it down with anything on even a semi-consistent basis is probably not going to happen. :)



Thanks! Looking forward to the learning experience.

POR 15

I have been using it for over 30 years, from car to loco restoration.

A little pricy but you get what you pay for. They have other products that are also very helpful and their website is very informative.

Scott.

What's the difference between it and other brands as far as results go? I'd have to be able to justify the cost, especially in the area of long-term maintenance cost savings.

Yeah, it's not about brand. I realize consumer advertising has hypnotized people into believing that. Fact is, the best products out there don't advertise anywhere you'd see it. Forget brand, really, paint is about chemistry.

- Rustoleum red is a fish-oil based primer with some anti-rust additives.
- POR-15 is a 1-part urethane-modified alkyd or oil using ISOCYANATES. *
- Variprime, Awlgrip etc. are 2-part epoxy primers, using bisphenol-A*.

* Isocyanates are the ingredient that makes Imron so damn hazardous to spray. Epoxies have the same basic issue but not as extreme: they are all immune system sensitizers. You can become allergic to the product and have reactions from red skin to stopping breathing. Treat them all like Imron unless you are brushing, as that greatly reduces the risk and slows the damage of cumulative exposure.

Rustoleum dries and cures by interaction with oxygen in the air. POR-15 cures by interaction with water vapor in the air. 2-part epoxies cure by its components interacting with each other. Epoxy cures in a sealed container, and I have the hockey pucks to prove it LOL! It will also soak into porous materials (wood, iron) and cure there. That's hard for 1-part primers to do.

With 2-part coatings, these toxic chemicals are fully consumed by the curing process. The result is a nontoxic, non-reactive polymer which is impervious to its own solvent. Until then, there's a mild issue with breathing sanding dust from uncured paint. 1-part coatings soaked into wood may not be fully cured.

Rustoleum and POR-15 claim to be suitable for painting over old rust (prep level SSPC SP7, you've wire brushed all the loose stuff off.) 2-part epoxies generally call for media blast to near white (SP10) surface prep. I find Awlgrip 545 performs over rust if I clean to SP7 then neutralize with rust converter (phosphoric acid), even though it's not a metal primer (other 2-part epoxies are, e.g. Variprime.)

Without topcoat (which is really abusing a primer); I find Rustoleum performs shockingly well despite its dirt cheap price, and it lasts several years exposed to UV and weather without topcoat. The 2-part epoxy primers, and POR-15, are by nature destroyed by UV, and they say so flat-out.

Other than that, Rustoleum is exceedingly simple to paint, paint out of the can if you like. 2-part epoxies you obviously must mix batches, keep unused mix in the freezer to slow curing, keep it off your skin, and use a bunny-suit when spraying due to the BPA. POR-15 is much more complex yet to deal with. All the above applies, you have to paint out of a cup, not the can, the can will glue itself shut permanently unless you employ certain ricks, you cannot shake the can to mix it, and It's also very finicky about prep and that requires more products of theirs.

Remember too - POR 15 is NOT topcoat. You will need to put a topcoat on either POR-15 or any epoxy primer, and you'll need to do it within a few months at most. Rustoleum seems to be more tolerant.

Sitting down?

Rustoleum $38/gal.

Awlgrip 545 $75/gal.

POR-15 $150/gal. + lots of waste because the stuff is so hard to handle.

Awlgrip Topcoat $180/gal. --- this is a "better than Imron" 2-part polyurethane topcoat. I mention it for reference since, like POR-15, it is about 20% isocyanate. I'm guessing the isocyanate is the big factor in the price of POR-15.

Honestly I'm not happy with any of the above. What I want is a 2-part epoxy resin like 545, but with the additives to provide the rust resistance of Rustoleum. That is brushable. I have not found that product yet.

I'm not sure how much this product currently costs, it's been years since I last purchased it. I believe it should still be under or not much over $40.

The product name is OSPHO, Dave can attest to just how well it works.

http://www.ospho.com/

It is readily available at must hardware stores but is found to be a bit cheaper at actual paint stores.

Cheers, Jason

Ospho.....a practicing historic preservation conservator and architect turned me onto that product and I've had good luck with it. I think the active ingredient in it is dilute phosphoric acid....but I'm an English major, not a chemist and so old the periodic table was only 4 elements when I went to school, so get better advice.

Whatever it is, it turns the rust on the surface into a paintable inert protective layer and doesn't cost much in the process. You apply it with a cheap disposable brush right out of the gallon jug, and a gallon goes a pretty long way. I think we did the boiler on the decapod with just one.

Jason is dead on about going to the sort of paint stores that deal primarily with contractors, not the kind that homeowners go into for swatches.

dave

I have not repainted a locmotive but I have used rust converter an many smaller projects.

If you use a rust converter, if the time comes for operation the the rust converter will need removed. At high temperatures the rust converter will fail and cause the paint to bubble. It might be OK on jacketing, running gear and the like, but not on the boiler. I found this out when I used it on and exhaust manifold.

For the rust converter to work right you need to remove loose rust but leave a light coat in place. In general, dark colored rust - bad, light colored rust - OK. It will not work right when the rust has penetrated the metal, as it must be sealed between the metal and the paint. It will not work right on a heavily rusted surface until most of the rust is removed and it can penetrate to the metal. Do not clean to bare metal, as there will be no rust to convert. Do not leave only the rust converted surface without top coating as it will start rusting again soon.

I generally use brush-on Extend which is available in most home stores and hardwares, but can be fond and in larger quantities (I have never done a project that large.) It is currently marketed by Loctite but used to be by Duro. I see it online for $329 for 5 gallons and $110 for 1 gal. I usually get a quart. Generally, I wire-brush or steel wool (you can sand too), rust preservative, then Rustoleum rusty metal primer, then Rustoleum finish coat following the instructions for each. The longevity is much greater than straight paint or even rust primer and paint. I like brush on Extend as it is water cleanup when wet (NOT when dry), is easy to work into rust pits with a brush and has very little odor. It will stain clean metal or anything else it touches.

I prefer the control of the brush. If you brush it on you don't have to worry as much about it getting where it should not or about breathing the aerosol, and you can make sure it gets into the nooks. I have a can of spray Extend only for places a brush cannot reach.

Like other rust conversion products, Extend is tannin and weak phosphoric acid. The acid is weak and has never inconvenienced me when I've gotten it on the skin, except for the stain. I expect the Ospho works about the same and it is cheaper in the large containers. There are several other brands as well.

Do NOT mistake Naval Jelly for a rust converter. It is a rust remover and must itself be completely removed before priming. It is also caustic (not so weak phosphoric acid) and will burn the skin and nasal passages.

Outside of painting, seal the upper parts of the jacket (the sheet metal that covers the insulation) so no water can get into the insulation and be held against the boiler shell or jacket. Don't seal the bottom completely so water that gets in will not pool inside. Importantly, maintain your coating of time, re-coating any areas that crack or fail as they will spread like cancer.

If you are patching the jacket with steel, make sure the patches and seams are completely sealed with paint or sealant. Do not leave air or water a route to exposed steel inside or out. Keeping oxygen away from the steel is the key. If you seal after you paint use 100% silicone calk, if before use paintable latex calk. Nether will hold up if the locomotive is re-operated.

LPS3 rust inhibitor http://www.lpslabs.com/product_pg/corrosion_pg/LPS3.html is a modern version of Cosmoline. It dries quickly to a hard slightly waxy finish that doesn't tend to attract grit. It's also not a bad lubricant. It's easy to remove later with diesel or kerosene. I've used it to protect axle bearings, air pump pistons, polished valve gear, etc. Glop it on wherever you can, it helps keep moisture out. It's cheap enough to use liberally, and runny enough to penetrate where you can't reach with a brush./

Hardware stores sell it in aerosol cans. It's a lot cheaper in 1-gallon jugs.

Ummmmmmmm.........actually, given that the boiler will be covered with lagging and jacket, it sort of makes it the best place for using rust converter if you're worried about cosmetics. So what if the protective paint hidden under the lagging fails when heated? The heat itself drives out moisture and any loose paint can't be seen. What's the problem?

Also, yes about sealing jacket patches ON TOP. Leave spaces on the bottom for any water that does penetrate to flow out freely.

dave

Ugh, brand names again.

OSPHO is PHOSPHORIC ACID. As the name might suggest. The active ingredient is phosphoric acid. There are many brands of phosphoric acid out there. I've tried three. The only difference is the concentration or the additives - those additives are there to help the acid do its magic, i.e. stick to the work or be less runny or not dry too quickly.
http://en.wikipedia.org/wiki/Phosphoric ... st_removal

Good phosphoric acid SHOULD be runny like water. Yes, it's hard to deal with vertical surfaces. There are some brands found in auto-parts stores which add latex to the acid to make it more goopy, however the latex will mess up the next coat of paint. Same for rust converters which claim to be also primers.

Uncorrupted phosphoric acid is hard enough to find - that I take it where I can. I would hate to see someone drive 50 miles to get OSPHO specifically when other brands are closer. Unless there's something "mad genius" about the other brand that I have yet to encounter.


Right... though there's no harm in cleaning to bare metal, the rust converter just won't have any effect there. If you're dealing with a mostly phosphoric acid rust converter, you rinse off the excess (unreacted) acid with water. If you're dealing with one of those latex-y converters, or the "primer too" types, then you may wind up with an inferior primer between your bare metal and your real primer.


Weirdly - not. I just looked at two versions of the MSDS and they seem to call out butosyethanol, acetone and formic acid, then in another MSDS, tannic acid. No phosphoric acid in it.

http://www.rshughes.com/images/products ... LXrJjw.pdf
http://www.loctiteproducts.com/msds/S_T ... D_msds.pdf

That is an MSDS I might expect to see on paint, not rust converter.

Doug Debs mentions LPS-3. Here is the MSDS.
http://www.lpslabs.com/technical_info/msds/10322.pdf
Here the vast bulk of it appears to be distilled from crude oil. Just like Cosmoline.

Thank you all for the input and expertise on this. I'd like to note, however, that this locomotive has long since had its jacketing and lagging removed, and I don't know if it was kept. If put back into operation, I would wager to say that it would probably have to be re-fabricated, quite possibly without the aid of original patterns. No concerns about foam vs. wood vs. (I shudder at the thought) covering the whole thing in fiberglass.

So, that leaves the layer of light-colored rust on the boiler. It doesn't appear to be terribly bad (certainly doesn't look very pitted), but it's too tough to be able to take off with a wire brush, so there will be rust to convert on pretty much the whole boiler.

As Dave mentioned, since it's just for the boiler itself, I don't think there will too big of a concern if paint peels from it, provided it's not something that would somehow condemn the boiler for future inspections through messing up an ultrasound or damaging the structure, though I'd be open to hearing any experience to the contrary.

IIRC the paint that's on the locomotive is pretty much just on the smokebox, cab, and on the tender, all peeling badly. The plan is to take a wire brush, probably a brush head on an angle grinder, to knock the loose paint off first. Some of it really should be patched (specifically near the floor of the side of the cab where it has rusted through), but metal patching's not going to happen. This is more of a "hey, 'ya wanna go do that a minute if you get some spare time" project than a major officially-on-the-schedule-to-keep-things-rolling project.

I don't believe any of us had been thinking an epoxy. It sounds like it'd work pretty well, but my guess is we'll probably end up going with what the previously-mentioned volunteer is used to, which I believe was phosphoric acid-based rust converter. Good to hear about the UV issues, too - the plan is to use flat black Rust-Oleum over the top of it. Not exactly historically accurate - would have been a really pretty gloss black in service - but without doing a *ton* of surface prep (far more than we're currently able to allot to this project), it would look terrible. We spent almost a year on surface prep for our glossy red caboose, and it was already in good shape - if we let this project take more than about a week, the same perfectionism will probably take over. :)

Think of this as one level up from throwing a big blue UV-disintegrable tarp over it. Quick project - got enough other stuff falling apart right now that we would need to get it done and move on. It's not even close to the only rusty thing around.

That LPS3 (or alternately whatever the non-branded generic active ingredient only version is, assuming that's available, or whatever's closer to where we're working) looks like it'd be a pretty good option for moving parts, but is there any advantage to that if we'd be putting Rust-Oleum (one brand I do not intend to change) paint over the top of it? And with it having a waxy surface, does paint adhere to it well?

So I guess my two remaining questions from this are:

1. Paint, or LPS3 + paint?

2. Rust converter + ultrasound acceptable?

Paint won't stick to LPS3 or any similar waxy rust-preventative product such as RustLick or some other variant of Cosmoline.

Use LPS3 to help keep water out of bearings etc. For example, driving wheels do not a perfect side-to-side fit inside the driving boxes. The "lateral motion" here results in a >=1/4" wide gap on at least one side of the locomotive between the bearing brass end and the driving wheel hub. Rainwater runs down the boiler and drips onto the running gear right in this area. The wheel-to-bearing gaps trap rainwater and feed it into the main axle bearings. Result: serious axle pitting. Drizzling LPS3 into the joint helps waterproof it. Then get some 100%-cotton sash or clothesline cord, soak it in LPS3, and stuff this "instant gasket" into the large gaps.

The same clothesline-gasket technique should be used to keep water out of the main rod and side rod bearings on the crankpins. Leave a gap at the bottom so rainwater can't pocket there.

- Doug Debs

Rustoleum rusty metal primer is very, very effective for the money. Maybe in S.F. it is $38, but here in Ohio we're still paying right around $30 and its available at every Lowe's. So if you assign a value to ease of obtaining, the Rustoleum is even more cost effective.

Nobody has mentioned Amerlock 400, a surface tolerant epoxy made by PPG. I experimented with a 2 gallon kit of it last summer, spraying it on all sorts of intentionally unprepared rusty surfaces. 1 coat, no primer, and after a year no rust has broken through the coating. It is $75 a gallon and when we get into the full swing of repainting at Carrie Furnaces will most likely be the coating we use.