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, and wash it off with industrial grade liquid detergent and a large, abrasive green scrubby cloth after the proper time they recommend to let it sit on the affected areas. (Overnight.) I highly recommend to take a drywall sanding swivel pad and pole and attach 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 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. Let that dry as directed, then without much delay, you need to put two finish coats of high gloss oil based urethane 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. I like the ICI brand available at ICI paints in Hilo and also Kona. Hilo store is near HPM hardware on the main drag. It costs about $35 per gallon. 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 urethane 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 4-5 years, or as needed, and your containers will most likely out-live you.

How to do it exceptionally well

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.

Ceramic paint to reflect heat

To reflect the suns heat, we highly recommend “Hawaiian sunguard” ceramic elastomeric coating applied 4 coats thick. (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 this coating, then you only need to use the oil based urethane 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. Again, if you don’t want to hassle with the POR-15 product, at least use the acid, the BIN primer and the urethane oil enamel. If you want to use the ceramic paint to reflect heat, then you only need to treat the grinded areas with the BIN primer and the oil based paint. Finally, If you don’t want to use the ceramic paint, then paint entire container with two coats of the oil based paint. I know this process is expensive and somewhat complicated, but if you do it, you will have total peace of mind with your containers and that evil thing we call rust.

Keep container off the ground as that will make the floor rust out. Unfortunatley, 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 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 $1000 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 more than $1000 total outlay, 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. 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 $500. 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. A metal container structure behaves like a wood home with 4 coats of this ceramic coating on it.