What Gets Sprayed

Aerosol rust sprays and brush-on rust paints have a place, and for a hinge or a bracket they are the sensible choice. What they cannot do is put enough material on the metal to matter.

A rattle can leaves 1 to 2 mils behind after the solvent flashes off. A brushed rust paint leaves 2 to 3 per coat. What gets sprayed here is 20 to 80 mils in one pass, and none of it evaporates — the products are 100% solids, so what leaves the gun stays on the steel.

The reason it can go on that thick without running is speed. Two components meet at the gun tip, mix, and start reacting immediately. Three to six seconds later the material has gelled and stopped moving. That is why you can spray the underside of a trailer frame at full thickness and nothing drips onto the shop floor.

It is also why you cannot brush it. There is no working time — nothing to dip a brush into. That part is genuinely a limitation, and it is why most small jobs get done by an applicator rather than in a home shop.

OR93BL is the default. If the surface mainly needs to stop getting wet — frames, underbodies, implement bodies, gates, panels — this is what goes on, and it is the least expensive of the three per square foot.

Flak Jacket 1 (FJ1) is for surfaces that get used. Bed floors, trailer decks, anywhere loads get dropped or dragged or people stand. Higher build and tougher, so it takes the knocks that would eventually cut through a thinner film.

Flak Jacket Pro is for the parts where material actually grinds against the steel — loader buckets, chutes, spreader beds handling aggregate or fertilizer. It costs more and it is worth it only in those places. Do not let anyone put it on your whole trailer.

7001 primer goes underneath on wood decking, galvanized, and sound existing paint. It is brushable and rollable, so if you want to save some labour on the invoice this is the part you can do yourself the day before.

Most single-unit jobs use two of these — usually OR93BL on the structure and FJ1 where the work happens.

People ask regularly whether they can buy a kit and spray it themselves. Here is the straight version.

These products require a plural-component proportioner with a heated hose — Graco Reactor E-20 or E-30 class or equivalent — that heats both components to around 160°F and pushes them at roughly 2,000 PSI to a mixing gun. It is a serious piece of capital equipment, not a rental-counter item, and running it well takes practice.

For one trailer, one truck, or one implement, buying or renting your way into that makes no economic sense. Hiring an applicator who already has the rig hot and the material on board is cheaper, faster, and produces a better result.

Where it changes: if you are a farm with a yard full of implements, a small fleet operator, or a shop that does bodywork or fabrication, the arithmetic can flip. At that point talk to us about equipment before you spend anything — we do not sell rigs, so we have no reason to talk you into one.

Either way, the prep is yours if you want it. That is real money saved and it is work most people can do with tools they already own.