1972 GMC Project Update

My hands currently have a slight gray tint to them.

Over the past two weekends I have been working on sand blasting and painting the control arms that are part of the rear suspension on my project truck.

After spending several hours the first weekend sand blasting I had what appeared to be two new looking control arms. Nice gray bare metal. The casual observer would have stopped there. Between the two pieces of stamped steel there was a gap just large enough to college small pebbles and dirt. These gap on both members were completely encased with rust.

Attempt to blast the grime out made slow progress. My next step was to marinate them with penetrating oil and WD-40. After letting them soak a few nights I used a hammer, a small punch, a screw driver, and a putty knife to knock this stuff loose. After about 3 hours I had about as much grime removed as I could hope for.

The next step was to spray some phosphoric acid based rust remover into the seem to clean up any rust in gap. And then I cleaned it out with Simple Green degreaser to remove any loose dirt that may have remained.

Once the inside was clean, it was time to clean it up for painting. The process of cleaning the gap had taken a few days and some surface rust had formed on the outside both suspension members. First I thoroughly cleaned both items with Marine Clean (also a degreaser), and then treated them with POR-15's Metal Prep (also phosphoric acid based).

Using the Metal Prep is pretty amazing. The surface rust just disappears before your eyes. (My sister likened it as one of those Billy Maze Oxy-Clean commercials). After 30 minutes of continuous metal prep application, a good rinse with water, and drying the parts off, I was ready to paint.

My intention was to use POR-15 on these just like I did on the frame. Most of the other stuff I have used Eastwood's Chassis Black on. I like the Chassis Black because it is easy to spray on. I attempted to thin (using POR-15) and spray the POR-15 but it did not seem to like my spray gun. I resorted to painting the parts using a foam brush.

The parts still need one more coat. I will have another go with the spray gun but I suspect I will end up painting with a brush again. I really like the way this stuff looks when it is dry, but it has been a real pain to apply it. If I have success with the brush I will let you know (and I will be using POR-15 on the differential.) If things don't go well, I will spray the Chassis Black on the diff. It always looks good and it is easy to use.

Another thing to mention. The POR must be cleaned up immediately if any is spilt. If you get it on your hands and don't remove it immediately, you will be wearing it til it wears off. Did I mention my hands are gray?

After several points during this entire expedition, I thought I should snap a few pictures. Before I started blasting was a good time, but I had already gotten dirty setting up the equipment and did not want to go back in the house until I was done. After the blasting was complete would have been a good time also, but I delayed thinking I would snap some shots before I painted. The before and after for the rust removal would have been impressive also. It looks like the only pictures will end up being shots after the paint is dry.