Six months ago, (June 2012) we reviewed Rust Bullet rust prevention paint. As we said then, the best way we had to see if the paint works as advertised was to expose it to the environment where the protection was most required. We put it on the bare ground behind our garage and left it for the six months.
Our test piece where it had 'lived' for the last six months...on the ground behind our garage.
The piece weathered 90+ degrees of Virginia summer, and sat under 2 inches of snow in December. We then brought it into the garage and checked it for any rust.
After 6 months all we did was accumulate a little dirt...no rust was apparent.
Of course, any paint could probably protect rust from forming for 6 months. But what we specifically were looking for were signs of continuing damage done by the rust that was pre-existing on the piece when we painted it. The paint was solidly adhered to the metal and there were no signs of any adverse activity beneath the paint.
Now for Phase 3. We're going to continue our test, but locate the piece next to the road where it'll be subjected to road salt as well as whatever the weather can throw at us. We'll be reporting back in the summer.
[Editor's Note: For the Phase 3 part of our Rust Bullet test, we put our test panel close to the road (tied to a tree with wire close to the ground) where it would get a healthy dose of salt spray and other road dirt. It remained there for about 2 months before it disappeared.]
When asked by Rust Bullet to do a product review, we were faced with a bit of a quandary. First of all, Rust Bullet is one of our advertisers. Secondly, it is critical that Second Chance Garage maintains its integrity. It is particularly important on the internet, where your integrity is all you have.
So we decided to proceed, and decided to let the chips fall where they may. If our testing of a product does not produce results as advertised by the manufacturer, we really don't want advertisements on our site misleading our readers. If a product does work as advertised, it could be an honest solution for many problems car restorers face.
Rust Bullet manufactures a variety of rust inhibitive coatings. For our review they sent a formulation specifically designed for automotive uses.
This is where we started...lots of rust and pitting.
For our test, we used a rusted and pitted splash pan that we had in our garage. It was in pretty bad shape. We wire brushed it to remove any scaling and flaking rust, then wiped it clean using Eastwood's Pre, a painting prep cleaner. We then made sure things had thoroughly dried. This removed any dirt, grease and other contaminants from the piece.
A wire brush easily removed any loose rust and scale.
After wiping dirt and grease off with Pre.
Directions for using Rust Bullet are precise. Options for application include Airless Spray, Conventional Spray, HVLP Spray or Brush/Roller. For the purposes of our test, we decided to use the roller method, using the recommended 1/4 to 3/8 inch nap synthetic fiber roller. Given the severe pitting in the piece, we weren't too concerned about roller marks.
Following the instructions, the first thing we did was to stir the paint until it became uniform in color. It was suggested that at least 3 minutes of stirring are required, however, it took us about five minutes of stirring to get the uniformity we thought we needed. If your Rust Bullet is over 6 months old, settling may have occurred and additional stirring time will be needed.
It's important to adequately stir Rust Bullet.
We poured a small quantity into our roller tray and immediately resealed the can. The instruction sheet was pretty adamant about not leaving the can open for too long; the paint is moisture sensitive and will tend to skim over. To further prevent skimming, Rust Bullet suggests that you cover surface of the paint remaining in the can with plastic wrap, with the excess wrap going beyond the rim of the can. They also emphasize that it's best to clean up the lip of the can, because the paint can seal it shut. New cans of Rust Bullet have a shelf life of about 2 years; opened cans about three to four months.
We began rolling on the paint using a cross-hatching method whenever possible to assure even coating. The paint is self-leveling, so on a smoother surface it will reduce the likelihood of roller or brush marks. The paint is fairly thin and covered nicely. The idea is to use thin coats, particularly the first coat; too heavy a coat could end up with bubbles in the paint, since the paint emits carbon dioxide bubbles as it cures. The waiting time between coats is two to four hours, depending on humidity levels. Rust Bullet is so sensitive to moisture that if it even thinks about raining outside, put off your painting until another rain-free day.
Newly painted piece a couple hours after first coat dried.
If you wait 72 hours or longer before adding a second coat, you will need to scuff the surface with 100 to 150 grit sandpaper before applying the second coat.
We applied our second coat the following day, again rolling in a cross hatch method. It is critical to apply two coats at a minimum. The first coat penetrates the rust and the second coat seals things up. You want to achieve a dry film of about 6 mils (about 0.006 inches) or a little thicker than a piece of standard paper.
Applying the second coat.
After curing for an additional 14 hours, we added a third coat and were satisfied that we achieved the appropriate thickness.
The following day, we applied two coats to the rear side, and the final coat the day after that following the same procedures.
In our case, since we used a roller, cleanup was a snap. We simply threw away the roller, and we wiped our paint tray out with a paper towel. After our third application, we also threw the paint tray away.
If you use Rust Bullet in a spray gun, cleanup is more demanding. Use Xylene or Toluene only. If you intend to use the same spray equipment for your second coat, and you use other types of solvent for cleaning, even a minute traces of the wrong solvent left in the spray gun can destroy the moisture curing reaction of the paint without any indication that you've created a problem. All paint must be cleaned from the spray equipment within 20 minutes of use, or it will harden and ruin your spray equipment. Should you get Rust bullet on your skin, it will take about a week to wear off. It's best to avoid this by wearing protective gloves. A NIOSH approved respirator with a 8051 vapor chemical cartridge and a R95 filter is also a necessity.
While the instructions were exacting, the paint handled smoothly and we experienced no difficulty in its application. But the proof is in the pudding, as they say. We're car restoration hobbyists. We do not have a lab, so we can't run scientific tests to see that the rust has disappeared beneath the paint. Rust Bullet doesn't form a film immediately, but penetrates the surface and dehydrates the rust. The dehydrated rust then becomes intertwined with the resin and becomes part of the coating. But we can't prove this. But we will test to see how well it holds up when exposed to the elements. And that will take some time.
Exposing our test piece to the hot Virginia sun.
As this is written it is now mid-summer. We'll give it about six months of exposure to hot southern Virginia sun and then, we will revisit it and report to you as to how well it fends off damaging UV rays. It'll be winter then and we will subject it further to such delightful circumstances such as road salt and wet conditions. We'll then report again about six months after that to let you know how Rust Bullet performs. Stay tuned.