What worked for me
Welcome
and congratulations on your Scrambler purchase
………….Now the fun begins.
Your post reminds of the situation I was in not long ago, I too live in a city whose name ends in Beach. My Scrambler had a very good covering of oil and grime from a nasty oil leak the PO could not locate and I would have described it as rusty underneath but solid. I figured if I did not do something soon it was going to be downhill living so close to the coast. I also was hoping I would be able to just clean up, get something on it and call it a day.
Most car washes have an engine degreaser and are a good way to get allot of it off some place other than your own driveway. Just wear some old clothes and be prepared to use many quarters and get very dirty. Be careful with the degreaser and painted surfaces, some I have used can do some real damage to paint. I did this, then drove a few miles and was able to locate my oil leak (fuel pump diaphragm vent) which turned out to be a blessing because it made a good rust inhibitor all the way down that side of mine. It is important that whatever type product that you use to be successful for treating or painting metal that it be grease and oil free. I found that the engine degreasers like Gunk work best on the heavy built up grime but not the best for general degreasing. I also used a product named “Marine Clean” that worked real well for degreasing before painting or any type treatment and worked for removing paint remover after using. This was sold with the Rust Bullet I used and believe it is the same product POR 15 uses for one of their steps. You will want to make sure that you rinse off all the degreaser also. I would degrease, pressure wash and then used a leaf blower to remove any droplets or puddles of water to avoid any flashing or rusting. With all the degreasers be careful with painted surfaces if it is a strong mixture. For a mild degreaser I would use something like Dawn dishwashing soap.
The best way to handle rust is to remove it completely down to the metal like sandblasting, but sometimes that is not practical. Any rust treatment is going to require you to remove any loose rust. I used a couple different phosphoric acid treatments. I used Ospho in a few places and it is to be applied then left to dry over night before painting. I had used some Ospho in the floor pan area then some primer. Where the primer was on top of the Ospho the paint remover would not even remove it but it would remove the primer on the non treated area. Here are the directions for it.
http://www.ospho.com/directions.htm
I also used another phosphoric acid product that was an optional treatment for the Rust Bullet that was named “Metal Blast”. I would imagine it is similar to POR 15’s Metal Ready which is another one of their steps. It was not as thick or sticky as the Ospho and was wiped on and wiped off or could be washed off. If you worked on it long enough it would remove all but the heaviest rust down to metal. The rust that was left would turn black like the Ospho. If it were washed off it would leave a white powder coating that you needed to remove before painting. With the acid treatments you will want to make sure there are no puddles or runs. Your paint will almost bubble up immediately. I would apply and then wipe it.
I also used a rust converter that worked good in the hard to get to places because it was a one step process. This seems to be holding up surprisingly well. It leaves a nice acrylic coating. There is more on that here.
https://www.cj-8.com/forum/showthread.php?t=24824
One of the most important things I learned was to read the tech sheets and directions on everything you use. If you had the product for a little while it may be a good idea to look on the internet for the most up to date sheet. Two products I used had major changes by the time I used it which was only a few months. You should think several steps ahead to avoid compatibility issues. For instance, the phosphoric acid should not be used under latex paint and some epoxy primers. It is best used under oil based paints.
Mine may have been in worst shape, but the more I got into it, the more I wanted to do it right and ended up doing a full body off. Here are some of the pictures.
https://www.cj-8.com/gallery//showgallery.php/cat/500/ppuser/17534
