LaRue uses wire fencing as sacrificial steel. Place sacrificial steel electrodes around the edge of the container, and tie them together with wire.” Then stir in about 1/3 cup of washing soda for each 5 gallons of water. “The setup is really very simple,” LaRue says. Meanwhile, the positive cable is connected to another piece of iron or steel, known as the sacrificial electrode, which is placed into the tank. The part that needs to be cleaned is placed in a solution of water and washing soda, and then it is connected to the negative cable from a battery charger or battery. Markets Analysis Back to Markets Analysis.I will post some other photos after this message. Note how much darker the ET is in most areas, due to the sunlight. Photo 3 - Probably STS-91, not certain, shortly before launch. Photo 2 - same ET with STS-91 very shortly after arrival at pad, before RSS is rotated into place. Photo 1 - 1998 - first super light ET, on arrival at KSC Some examples below of various ET’s/missions. I simply used a cheap spray can of rust-colored primer which was a decent match. On that one, the ET was more of a rust color. The ultimate scale model I built, was the only shuttle mission I ever saw launch, STS-47 in September 1992. And if it is a mission since 1998 or so, some parts of the ET may be lighter/darker than others, due to the “sunburn effect” of most of the tank getting darker in the sunlight while other parts are protected by the pad’s RSS.
So, the “right” color really depends on what specific mission you are modeling. So when the RSS is rotated back for launch, the ET has a sort of a "sunburned look", the exposed areas are darker than the areas protected by the RSS. But the RSS covers a lot of the tank from direct sunlight. The big thing is that being exposed to sunlight for weeks on the pad, the foam gets significantly darker. When rolled out, they might look a little darker, but not much. In any case, the tanks can have an almost butter-yellow color to them when they arrive, as seen below. I do not know if the foam itself is any different, or if the ET's are being produced closer to the time of launch rather than being stored for a very long time. More recent ET's, "Super Lightweight Tanks", first flown in June 1998, are even lighter. Only the outer part gets dark, like a "rind", so when the rind is cut away the exposed old foam is lighter in color. The other, where old foam was ground down or cut into for some reason. Such as building up the foam ramps that are along the right sides of the conduit lines. One, where new foam was applied in places for various reasons. On tanks that look dark orange or rust, but also have lighter orange or yellow-orange places on them, what is that about? Two causes. The only truly really useful color comes from photos on the day of launch and even then it depends on the lighting, exposure, and film color sensitivity. Also, in some photographs the color may vary due to the exposure or lighting. Due to slips in launch schedules, some ET's sat in storage for a very long time, so they got even darker. Both age, and especially exposure to sunlight, causes it to darken. The foam originally is much lighter in color. After that, they have been the natural color of the foam insulation. I suggest going to this page on my website, which shows a lot of ET details, including various ET’s:īelow is part of what I wrote on that page: it's BY FAR the simplest/easiest.Īs rocketguy101 and Luke Strawwalker said, the color of the ET is the spray-on foam’s natural color (except for STS-1 and 2). You might also want to check THIS ONE out. The whole first page is mostly about paint tests for the ET. Here's a thread with relevant pics and some paint tests I did on my DR. the stuff follows the exact same color changing process.
Ever look at spray foam on the outside of your house, say applied around utility penetrations around the walls, water pipes, etc. once it's exposed to UV rays from the sun for awhile, they turn that orangish color, getting a redder/browner "rustier" color the longer they sit. so therefore the ET's all went to their "orange-ish" weathered spray foam.ĮT's coming out of the assembly building at Michoud are a creamy tan color- just like spray foam in a can is. The shuttle ET was painted white on the first two missions- the engineers rapidly figured out this was a waste of time/effort/money/weight, because losing 600 pounds of paint off the ET meant another 600 lbs of cargo could be carried by the shuttle. Not primer either- it's essentially, for all intents and purposes, "spray foam in a can".