Rust Treatment

vidsolve@gmail.com

Treating surface rust properly for maximum container life span

The process is simple, but you need to do things in the right order, the right way, with the right products.

Warning- Do not get acid on skin or in your eyes. Most of the products we recommend here are unhealthy to breathe. Always use a properly working double respirator made for organic vapors, and professional grade particle mask when grinding. Thank you!

Step one- Get a small, light weight, high rpm (12,000 minimum) grinder- 4.5” is a recommended diameter, but any size will work. We recommend the bosch 7.2 amp grinder available at gaspro, it is the cadillac of grinders, and only costs $78. You can use the ¼” thick metal grinding discs for the tough stuff, and the braided wire cups for those hard to reach areas. Large, heavy grinders will wear you out quick, they buck too easily, do not spin fast enough and are not at all recommended. Grind off the rust that is flaking on the surface down until you hit metal. Don’t worry about grinding every tiny rust vein inside the metal, just get everything off until you get to bare metal with little veins of rust inside the metal, and do that everywhere on the container. Do step two as soon as possible, don’t leave bare metal unprotected for more than 12 hours.

Step two- Apply the zinc phosphate acid treatment made by the EZ clean company called etch and prep, available at home depot for about $15/gallon as directed, apply liberally onto the grinded metal and let it sit for 4 or more hours. A pressure washer is the best if you can get one to blast off the rust in those deeper veins that the acid has eaten. I usually do 2-3 acid treatments on the rust, washing with a pressure sprayer after each application. This is easier than grinding into those veins forever with the grinder. When you have eaten down to bare metal as best as you want to do, wash the entire container with industrial grade liquid detergent and a large, abrasive green scrubby cloth. We recommend using a drywall sanding swivel pad and pole and attaching two large green scrubby cloths that are sewn together to the large rectangular swiveling pad. This is because they don’t seem to make a green scrubby long enough to reach across the swivel pad. The swivel pole pad fits inside the corrugated metal surfaces of the container really well. Doing this on your hands and knees is not fun!

From this point, you have two processes to choose from- doing it well or doing it exceptionally well. I will start with doing it well:
Spray or brush or roll entire container the minute it is dry after scrubbing with detergent with Zinser “BIN” brand shellac based primer. The Zinser product bonds very aggressively. It cleans up only with denatured alcohol, also available at home depot. You need to put two finish coats of high gloss oil based enamel. Do this one coat at a time, giving the first coat about 12 hours drying time. You only have 2 days max to put the second coat on, high gloss oil doesn’t stick to itself well after 2 days. The company that made the paint I most like, ICI Paints, no longer makes it, so rustoleum high gloss oil based enamel is adequate. Do not ever use water based paint on your container. It does not seal off air or moisture at all, it is worthless IMHO. There is something magic about industrial grade high gloss oil based paint on metal. Use a respirator for all painting as all these paints are unhealthy to breath. You can reapply a new finish coat on containers where they are exposed to the elements every 3-5 years, or as needed, and your containers will most likely out-live you. Always wash down with industrial liquid detergent and prime before putting on a new top coat of high gloss paint.

How to do it exceptionally well

Option 1- Once container is totally dry after the washing, apply one coat of the POR-15 rust treatment only on the grinded metal areas with a brush (not on entire container) and apply a second coat 20 minutes later approx. Two coats of POR-15 is essential! You cannot spray it, and a roller is wasteful, so use a large brush for big areas. Do not apply second coat of the POR-15 earlier or much later. Once all grinded areas have 2 coats of POR-15, let cure 24 hours or whatever the can says (I believe 24 hrs is right). Kona Marine or J&J hardware in Hilo are the only places to get POR-15. You can also order it online, just google POR-15 to get to their site. It is about $45 per quart, and goes a fairly long way. You need to wear a good double respirator as the fumes are horrendous, and there is no solvent to break it down, so don’t spill on yourself or anything important. Once you open a can, you need to use the whole can fairly quickly as it doesn’t store very long. I pour it into multiple smaller mason jars and use 1 entire 8 oz mason jar in one sitting. Be sure to not have much air in the mason jars, and cap tightly right away. I have successfully stored it that way for several months. Air exposure will cause the POR-15 product to get thick and set-up really quickly. This product is the best defense against rust in the world if you use it properly as I explain in this article. Once the POR-15 cures as directed by the company, then prime and finish paint as described above, right away. The POR-15 shuts out oxygen and water vapor exceptionally well, but it needs the industrial oil top coats as the sun breaks down POR-15 fairly quickly. Rust bullet is also a good coating that is similar to POR-15.

Option 2- If you don’t want to do such a nit picky job grinding rust, you can grind off the thick rust and not grind down to the veins, just knock off until you hit bare metal and don’t continue much further. Then apply a special rust penetrating sealer, then 2 coats of a special epoxy barrier coating, then finish off right away with an aliaphatic polymer paint. We can get these products for you and ship or deliver, call us for pricing and info. The Aloha Stadium project is using these products here on option 2, it is a lot easier than our option 1, but we feel that option 1 is better.

Ceramic paint to reflect heat

To reflect the suns heat, we highly recommend “Hawaiian sunguard” ceramic elastomeric coating applied 4 coats thick. This product has an additive called lipocryl, which makes the coating hold up exceptionally well with ponding water on the roof. That is very very significant and important. Other elastomeric coatings do not have the same performance with ponding water and severe weather conditions. We can supply you with the product, ship and deliver it, call for info and pricing. (If the ceramic paint is too much hassle or cost for you, you can achieve some degree of cooling if you use a very light color paint, and the high gloss recommended here also helps reflect heat.) If you use Hawaiian sunguard, then you only need to use the oil based enamel on the grinded areas and not on the entire container. Do not put the ceramic paint system down without first using the oil based paint on the grinded areas as that paint is very effective to help seal air and moisture away from the rusted areas that you have grinded. Even if you opt for either of our more extensive processes, the ceramic coating is recommended to reflect heat. Hawaiian sunguard utilizes a water-based epoxy primer that you can use on top of oil based paint once it has cured for only 2 days approx. The primer sticks to anything, like a magnet. Do not ever use any elastomeric coating without first using the recommended primer. Bonding is everything!

Always keep containers off the ground. Moisture wicks up from the ground, from a concrete slab and also on blacktop. You can put one on the ground only if you place a waterproofing membrane inbetween the container and the surface you place it on. It is obviously easier to put it on concrete blocks. We use 16” X 16” X 5” thick blocks from home depot, they cost about $10 each. Call us for recommendations on how to do this properly. Unfortunately, it is much too much trouble to treat underneath the container floor, but if you’re off ground, container floors rarely rust out completely unless you are right on the ocean. If you are concerned, you can put a rust-proofing compound from NAPA over the rusted areas underneath to help starve the rust from air and moisture. This rustproofing compound does stink for quite a while, and the vapors are not particularly healthy to breath, so we prefer to not use it for health reasons.

To conclude- it is so much easier and cheaper to work with a new container, which costs about $1600 more for a 40’ high-cube. Doing all this rust work and paying for all these expensive paints is not cheap and the labor is not fun. If you pay someone to grind the rust, you will pay a ton of money, so be smart and buy a new container and all you will need to do is keep it coated every 4-5 years or as needed. The floor on a new container is not rusty, it has fresh undercoating, so you do not have to worry about your structure crumbling after all the money you spend building it out. Again, we highly recommend the Hawaiian sunguard ceramic paint- it really works, and it is NSF rated for water catchment. Cost to put their primer and 4 finish coats on a 40' container is about $800. 4 coats is highly recommended to reflect and insulate the suns hot rays so most of that heat does not even reach the metal. Insulation inside is good, but not without reflecting as much of the suns heat first from the outside as possible. A metal container structure behaves like a wood home with 4 coats of this ceramic coating on it. We can supply you with Hawaiian sunguard, and instruct you how to use it properly.