In my recent drive to finally get around to doing some repairs on my 91 FJ80 I decided to start tackling the rusty undercarriage that Northeast Pennsylvania has graciously donated to me.
After installing an exhaust I noticed that my vehicle was in a position where I could either bring it to a junkyard in a few years, or get on top of the rust issue and buy 5 more years of useable life. The odd rusted brake line has been popping up recently, as well as taking a rust bath anytime I wrenched on anything underneath it.
I completely understand that the right way to take care of this is to remove the body and have the frame media blasted and then painted / galvanized / powdercoated, and then do any repairs on the underside of the body when they're separated, but I don't have the space or the budget for that endeavor - so I decided to do the best I can with what I have.
After doing some research online about what others have done I decided to go the route of cleaning the heck out of everything I could see, repairing whatever has holes, and painting. I began by putting the truck up on ramps, and pressure washing everything as well as I could. After two pretty thorough pressure washing sessions, I wasn't really happy with how it was turning out. 27 years of grease and dirt was caked into every nook and cranny, and it was pretty reluctant to leave it's resting place. I got professional strength simple green off of Amazon (the purple stuff) and went to town pressure washing again. After two subsequent pressure washing with the Simple Green I was satisfied that I got most of the crud off of the truck.
I had a gallon of phosphoric acid left over from a previous rusty project with this truck, so I diluted down to 50% and sprayed everything that resembled rust. Phosphoric acid is a rust converter which chemically converts rust to iron phosphate which is inert and paintable. I waited for the telltale white haze to form, and I rinsed the truck off.
All of the auto body places nearby insisted on a perfectly clean surface prior to painting. Yes, I understand this is preferable but I didn't have the time or the energy to get everything ground clean. Plus, why would I spend hours and hours grinding everything clean and leave the inaccessible portions of the underside rusty? I considered POR15 and similar products, but I've had a few bad experiences with POR peeling off after a few years so I discounted that idea. I made my mind up that I wanted some sort of epoxy.
I work in large construction, so I gave one of my commercial painters a call and he suggested Sherwin Williams Macropoxy 646. One of the main benefits is that it's designed for 'marginally prepared steel' - it's also suitable for marine environments and steel which is intended to be submerged in water. He also had a few gallons left over from a previous job, which he gave it to me.
After installing an exhaust I noticed that my vehicle was in a position where I could either bring it to a junkyard in a few years, or get on top of the rust issue and buy 5 more years of useable life. The odd rusted brake line has been popping up recently, as well as taking a rust bath anytime I wrenched on anything underneath it.
I completely understand that the right way to take care of this is to remove the body and have the frame media blasted and then painted / galvanized / powdercoated, and then do any repairs on the underside of the body when they're separated, but I don't have the space or the budget for that endeavor - so I decided to do the best I can with what I have.
After doing some research online about what others have done I decided to go the route of cleaning the heck out of everything I could see, repairing whatever has holes, and painting. I began by putting the truck up on ramps, and pressure washing everything as well as I could. After two pretty thorough pressure washing sessions, I wasn't really happy with how it was turning out. 27 years of grease and dirt was caked into every nook and cranny, and it was pretty reluctant to leave it's resting place. I got professional strength simple green off of Amazon (the purple stuff) and went to town pressure washing again. After two subsequent pressure washing with the Simple Green I was satisfied that I got most of the crud off of the truck.
I had a gallon of phosphoric acid left over from a previous rusty project with this truck, so I diluted down to 50% and sprayed everything that resembled rust. Phosphoric acid is a rust converter which chemically converts rust to iron phosphate which is inert and paintable. I waited for the telltale white haze to form, and I rinsed the truck off.
All of the auto body places nearby insisted on a perfectly clean surface prior to painting. Yes, I understand this is preferable but I didn't have the time or the energy to get everything ground clean. Plus, why would I spend hours and hours grinding everything clean and leave the inaccessible portions of the underside rusty? I considered POR15 and similar products, but I've had a few bad experiences with POR peeling off after a few years so I discounted that idea. I made my mind up that I wanted some sort of epoxy.
I work in large construction, so I gave one of my commercial painters a call and he suggested Sherwin Williams Macropoxy 646. One of the main benefits is that it's designed for 'marginally prepared steel' - it's also suitable for marine environments and steel which is intended to be submerged in water. He also had a few gallons left over from a previous job, which he gave it to me.
