POR15 vs Zero Rust and Eastwood's Rust Encapsulator A couple years back I made some comments on various websites whereby I said that I could not see HOW a spray-can product (such as Zero Rust and Rust Encapsulator) could have the same properties - and therefore work/last the same - as would an epoxy-based product like POR15 (and now RustBullet), which are single-part epoxy products. Some time after making those comments, Zero Rust people and Eastwood sent me some of their product and asked me to try it, which I did. After several trials in my own restoration shop, I still felt the same way, but there were a few voices - some in the profession - still saying otherwise. It was then that I decided to do some actual "testing" of these products. While not a "scientific" test, it could well be called a "real world" or "as intended" trial. The products were used as recommended, the way an enthusiast would use them in their own shops or garages. In every instance, both Rust Encapsulator and Zero Rust were applied from the spray cans supplied, using 3-5 medium-wet coats. The POR15 was applied with a brush in a single, medium coat. Regardless of the number of coats or the perceived thickness of product application, all products were applied per their instructions, at temperatures near 60F/15C and as you would in practice, to both cover surface rust and to give the metal some protection from further rusting, as advertised by all 3 products. I have 3 experiences (or "tests" if you will) that I'd like to share: In the first instance, I applied Eastwood's Rust Encapsulator and POR15 to either end of a spare tailgate for my 1946 Mercury truck. This item had lived outside for a long time and had developed an even surface rust, making them the exact surfaces applicable for these products. Since the application of these products, this particular tailgate remained inside my shop, dry, at temperatures between 7C and 25C. In this trial then, the products were not subjected to harsh conditions (as per a subsequent, ongoing test) so we can see how they age on their own. After about 2 years, we can see that the Rust Encapsulator has become somewhat transparent, while the POR15 has remained solid and opaque (solid). Again, this part stayed inside my shop all this time, so I'm not sure why the Rust Encapsulator would have deteriorated on the panel, though I can make an educated guess: if you look closely, you can almost see the rust of the tailgate coming back through the Rust Encapsualtor coating in some spots, leading me to believe there is a lack of solids in the product. From that, one may infer that this product may not provide a long-lasting coating, nor long-term protection. 1946 Mercury Tailgate: On the left is the Rust Encapsulator, on the right the POR15. Below: If you look closely at the photo below, you'll see how the Rust Encapsulator has - for lack of a better term - worn out. You can almost see through it to the rusted surface in some spots. If exposed to the elements outside, I would guess the product would provide less than optimal protection. Below is the POR15 coated portion. It still looks solid and opaque. There doesn't appear to be a weakening or wearing of the product and rust-through is non-existent. Of course that being a fairly "easy" test - and certainly not the one everyone wants to see - I did a second test where the part (thsi time a Chevy tailgate) was left in the elements for an extended period of time: This time all three products (POR15, Rust Encapsulator and ZeroRust) where used on a Chevy tailgate that had been exposed to the elements long enough to produce a heavy coating of surface rust. After proper application of all 3 products, the tailgate has been left outside, throughout the seasons. This test was started about 6 months ago, so not yet ready to be reported on, but I'll do a full posting on the results in another 12-18 months, depending on how fast I see differences in the performance of the products. This third experience (below) speaks to the composition of these products, their robustness, as well as their ability to resist chemical degradation and protect what is under them: Most of us know that brake fluid is highly toxic to paint. In the photo below, the brake backing and tie rod on a 1956 Chevy Truck restoration were brush painted with POR15, but the wheel rim was sprayed with Zero Rust. After assembly and bleeding the brakes - and getting brake fluid all over both surfaces - we wiped it all down and noticed that some of the Zero Rust from the rim had been removed by the brake fluid, while the POR15 was still intact. Several days later, as we were checking over various systems, we noticed that the bleeder on this side was leaking, again allowing brake fluid to run over the wheel and the along the tie rod. So now both surfaces where in prolonged (several days) contact with brake fluid before being noticed and wiped down and still the POR15 remained intact. Below: Up close, one could see the POR15 was completely intact and would likely never be impacted by brake fluid. It doesn't take a rocket scientist (lucky for me!) to know that products in a spray can just cannot dry to the same hardness as would an epoxy (single or dual component). If they could, they would harden and ruin the spray tips on spray cans so that upon second use, they would not spray again. For anyone that has ever used POR15 (which cures in the presence of atmospheric moisture) you know just how hard it dries. It actually WELDS the lid to the can and it dries to a hard shell, regardless of how thickly or thin it is applied. On a suitably prepared surface (key point - read directions carefully), I've found that POR15 bonds like nothing else you'll ever try. Disclaimer: I do not work for any of the companies that make or distribute any of these rust products. After posting several threads about my use of POR15, the manufacturers/distributors of Zero Rust and Eastwood's Rust Encapsulator sent me more product to use and try. POR15 has never offered me anything. While I know that these products have their fans, I have as yet not seen an instance where POR15 has been outperformed by them in my experience. The POR15 I applied to the undersides of the 1956 Chevrolet truck is still performing well and looking great 3 years later. The truck won 1st Place at the huge Draggins Car Show here in SK, I'm sure partly due to the great OEM "suede" look you get by just brushing POR15 on surfaces.
Glad to know that as I'd just ordered more por15 this morning. I have grand kids wanting to earn money so I'm letting them paint my 56 ford frame. Just gotta remember to make sure they wear rubber gloves - safety glasses and old clothes
Bravo! Product/tech archive would be a good place for this. Then it can be referred to when the question is asked several times a month.
That's good information. Thanks for going to the trouble to do these tests. Please do keep us updated on the outdoor test.
I've used POR15 for years with great results. A trick for sealing an open can is to put 2 layers of thin plastic over the can then the lid, easy to reopen then cut the plastic. Can also patch small rust holes, paint with POR15 then lay on fiberglass cloth then paint over again.
Thanks for th words gents. Studeynut makes an EXCELLENT point about using thin plastic (Saran Wrap, etc) between lid and can to seal it up for later use and still be able to remove the lid! Another trick is to move the remaining POR15 to a clear jar (Mason, etc), again using plastic between lid and jar. If kept cool and dark it'll keep for a year or more like this.
I have found that because of really nasty fumes associated with the POR-15 I only use it where I need something the run or seep into an inaccessible area. I have been using Rust Bullet for the open easily accessible areas. Both have been holding up really well for me and the Rust Bullet is a lot cheaper than the POR-15. Scott...
I just put the lid back on the can, and shake it a bit to make sure it's sealed around the rim. Tha next time I need it, I poke a hole in the lid with a pick, and pour out what I need. Then I screw a sheet metal screw in the pick hole and give it a shake to seal it up. Repeat next time it's needed.
Not sure of the chemistry of these products, but I have had rust converters (the milky white ones that turn purple/black on curing)give off acrid fumes when welding close to them later - and any bare metal in the vicinity developing flash rust almost immediately afterwards Just something to keep in mined...
Another tip for keeping POR 15 from hardening in the can is to use your MIG welder. Kick off the drive roller, so you won't move the wire, and shoot the argon into the can and quickly close it, driving out the oxygen & moisture that hardens it.
Good idea ON THE ARGON Chopolds. I believe POR-15 doesn't adhere well if the surface is smooth. Any comments about this? Ago
Years ago in the unenlightened pre interweb thingy days I called the POR15 people and they told me that the reason that it is so tough and durable is that it is resin based - makes sense. My concern is that it didn't. Have UV stabilizers to maintain it's color and will fade if exposed to sunlight and take on a milky greyish hue - has this changed does anyone know? I would also be very interested to see a review or hear experiences of Eastwood's 2k chassis black, which is they are promoting as a 2 component ceramic based chassis paint in a two component spray can - presumably a catalyzed mix in a can....
Good comparision on those products E Tek, its nice to know what works and what doesen't A buddy of mine in CT is a dealer for KBS coatings,and brags that there stuff is better than even Por, it turns out the guy that owns KBS came from Por, we just had a little chat about the stuff they sell and it turns out they have solids of 60 unlike many of the others that don't have that high of solids and is UV protected, I haven't seen or used any yet but he has a couple pieces of exhast tubing painted with this stuff and tells customers to try to chip it and it won't chip, he hits quite a few shows in the east and may make it to Washington for the ATHS convention and show the 1st of June, and later this year I'll try it on a couple bus frames that need to be restored.
Real world confirmation of your results: The Eastwood Rust Encapsulator is a great detail paint for engine compartments and trunks because it goes on really nice and seems to attract dust less than some other paints (I have no idea why, but it does?), but as you noted it does NOT stop rust. I sprayed a nice heavy coat over a surface-rust patch on a pickup AND used the silver on a steel fence and both rusted right through the paint with a couple years' exposure to the elements. And I live in Southwest Missouri, not Northeast Ohio or PA! My guess is it wouldn't last one winter cycle back there. A friend who does live in Northeast Ohio has used POR-15 for years on various projects and tells me he's never had one rust back through. He loves the stuff.
Depends on what you call smooth. I would guess that POR mostly uses mechanical adhesion to stick to surfaces, that's why it is so stuck to rust. I've used it on freshly sandblasted surfaces with excellent results. I've also coated the insides of patch panels, new floors and trunks. I always do an acid wash (Picklex, Metal Prep, etc.) before putting on the POR. opens up the pores of the metal so it can stick better, and cleans any residue off. New metal is pretty smooth, even after metal prepping it, and it works well on it. Only time I've had trouble is with damp or humid weather, and "sweating" metal surfaces. It likes humidity to cure, but does NOT like a damp surface to stick to!
I've used POR with great results. Once poured the extra from the can into an empty cool whip container and forgot about it. When I finally remembered it, it was hard as a rock and over an inch thick! Use it for demos at school. Tough stuff.
Disclaimer: I collect antique trucks, big trucks. I sell KBS-Coatings RustSeal to pay for the fuel to get my antique trucks back and forth to antique truck shows. I use KBS products! I discovered them restoring a 1916 5 ton electric truck. Mr. E-tek point me to your address and I'll send you some KBS-Coatings RustSeal samples so you can include the results. One of the first attempts to tame rusty metal was Rustoleum, not the best, but the best we had at the time it was introduced. POR15 was the best there was for 20+ years. It's the first generation of moisture cured urethane paint tailored for rust prevention. I consider the other brands, POR15 copycats. That may or may not be true but it's it's been my impression. The second generation of of these paints formulated around 2008 and based on 25 years newer technology has emerged in products from KBS-Coatings. One of POR15's large resellers for reasons that aren't important here, split from POR15 with a vast knowledge of and years of experience with moisture cured urethanes earned from years of POR15 sales formulated a new line of products and started KBS-Coatings. They have a very talented chemist. They make their paint in northwest Indiana. What's different? Two big advancements, higher solids content and the introduction of UV protection which is still not 100% but its high enough you won't always need to topcoat it! The KBS -Coatings RustSeal solids content of was raised to 70% compared to the other brands at 20%. The introduction of UV protection, Rust Seal has UV protection that varies by color from 60% to 85%. Available in 10 colors because an item painted with Rust Seal that see's some UV rays but isn't always in direct sunlight now needs no top coat, i.e. chassis, engine compartments, etc. It's also good to over 400 degrees and which makes it an excellent primer for gas and diesel engines. On a properly prepared surface, which is the key to any Rust Sealing paints success, it seals so well others tell me it's effective in sealing seeping gaskets, the Detroit Diesel guys with the green leakers, LOL. State and city highway departments are painting their maintenance trucks with it because it is impervious to road salts and brine sprays. Boeing uses it to stop corrosion on new aluminum airplane wings. NASA used it on the launch towers, on what I don't know. If you're like me always trying to stretch a buck it's also less expensive. The bottom line is if you follow instructions and aren't satisfied that KBS-Coatings RustSeal doesn't work better than anything you've used before KBS-Coatings will refund your money. Forget the hype, and salesman like me - I sell the stuff, the proof is in the pudding! Eddy Lucast http://kbs.justoldtrucks.com [email protected]
Your tests are not quite fair. Get a can of brushable eastwoods. I coat and let cure, then recoat. Each have their uses but I agree por15 is the bomb
I enjoyed your tests. 23 years ago, I started selling moisture cured urethanes out of the back of my Avanti. I founded the MasterSeries Coating Line in 1988 and prior to that, I sold POR-15. For many years I've watched companies claim that the black moisture cured urethanes seal rust. Well, that's not exactly the case. Any type of paint, applied over rust, will seal rust to a certain degree and I have been spreading this message for a good many years at many different shows. In 1988, I met an industrial coatings expert at one of these shows who explained the technology to me and directed me to the Mobay Chemical Company in Pittsburgh. He told me to call their technical department with any questions and problems I had. It was an interesting conversation. It seems that in the late 60s and early 70s, Mobay developed a bridge primer that was moisture cured. It only came in one color, and that was silver. The reason being, the resin is completely waterproof and when exposed to moisture, it would harden to a waterproof seal. But, waterproof doesn't stop rust. To stop rust, you must deprive it of oxygen. The resin was heavily compounded with non-leafing aluminum flake. This primer, in multiple layers, created a labyrinth where oxygen couldn't penetrate it. This made it waterproof AND air-tight. The industrial name for this coating system is the "Three Coat Polyurethane System". It is one of the most anti-corrosive systems in the industry and designed primarily for bridges, water tanks, galvanized roofing, and coastal environments. It would pass 8000 hours of salt spray and if it was scratched, the rust wouldn't go beyond the scratch. It was used over clean steel, sandblasted steel, lead paint, or marginally prepared surfaces where sandblasting was prohibited by law. Any other primer or paint could go over it, because when dry, it was solvent proof. Around 1978, it found its way into the antique car hobby by way of Stan Coleman Supplies. It was sold as a rust sealer and metal filler. A bit later on, the powers that be decided that the customer wanted black and not silver. So they removed the aluminum flake and substituted carbon black. Their reasoning was "it's the same stuff". Now keep in mind these powers that be, never painted a car or restored one. The problem is, once you remove the aluminum flake, it's no longer air tight, won't take sunlight, and certainly won't seal rust. It also dries slick and glossy, which is difficult to paint over. Aromatic resin, like epoxy resin, inherently is not sunlight stable. If it's heavily compounded with aluminum flake, it will only discolor slightly and in some cases, not at all. The moisture cured black doesn't contain any type of rust inhibitors (you can check the MSDS). It dries to a high gloss with no tooth for another paint to adhere to, which is better suited for concrete and wood. Black works well over the silver, under a vehicle where there's no sunlight. The Three Coat Polyurethane System is one of the most anti-corrosive systems in the industry, and that's the reason we've stayed with it for 23 years. Here's a comparison from the PPG data sheets: 2 coats of DP40, 5 coats of color, and 2 coats of clear does 500 hours of salt spray. 2 coats of silver and a urethane topcoat does 10,000-14,000 hours of salt spray and the rust won't go beyond a scratch. Think about that the next time you drive a bolt through a chassis or fender and the paint breaks. I hope you find this information useful. Moisture cured urethanes have gotten a bad rap, but if used correctly, they can provide many years of long-term results. Best of luck with your restorations.
I have used the spray-on AND brush-on Eastwood Rust Encapsulator and within a couple years the rust comes right back through the paint. That's true whether it's over light surface rust, heavy rust, or rusty metal sanded shiny. It is a good detail paint because it goes on so heavy and smooth but just is not a way to permanently stop rust (as they advertise).
On storage and handling, it's moisture cured, so any introduction of moisture will cause it to harden. The introduction of moisture is like adding a hardener and putting the lid back on--it'll harden down the road. To keep the moisture out, the trick is to not stir it in a circle; stir from the bottom up, up and down. Stirring in a circle draws in the moisture. Immediately pour out what you need into another container and replace the lid. You can use a paint brush with thinner. When you tip the can, clean out the gutter with the thinner brush and replace the lid. Saran Wrap between the lid and can also helps. Some moisture cures make a better glue than a paint. My favorite is to take an empty motor oil bottle, flush it out with thinner, and then pour the moisture cure into the motor oil bottle. When you need some, shake it, pour out what you need, and put the cap back on. A wide neck bottle like Amsoil works well if you have to put a stick in it. If it's hot and humid (like Florida in July), take the can inside where it's air conditioned, open it, pour out what you need, and reseal it. Adhesion problems? Make sure you use a metal prep. On sheet steel, scuff it with 220, treat it with the prep, and you'll find it sticks much better. When you use the black all by itself, the phosphate is very important. It'll certainly keep the rust from returning. Oh, and wear gloves and never use lacquer thinner to reduce it! Use urethane reducer in very small amounts, as these coatings cut quickly. Hope this all helps.
Good info. Nothing beats a real world test. I've been thinking about the various products out there. I think I'll stick with my original plan and use the POR.
Does anyone know the history of "Corroless' and how it stood up compared to POR 15? I have a quart that has never been opened and I intend on using it. Was sold by Eastwood.
I think I have a gallon of this,unopened,too... been in the basement for years.. I remember their testimonials about how good it was,but have no idea if it's really any good. Expensive for the time,like most Eastwood stuff....
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