Bad snake oil

[jim lee]

Saturday, September 30, 2017

I had the gallon of magic rust eating acid and I needed to at least try it out. When I picked up the acid, they tossed in a spray bottle of degreaser saying, “dump this out and use the spray bottle for the acid”. It was much cheaper to buy the degreaser than to buy an empty spray bottle. This was done as a favor to me, trying to save me some cash, just being nice. They didn’t think about the fact that I have a gallon of scary acid and they just tossed me a bottle full of a concentrated base. (opposites, yikes!) Luckily I noticed the potential chemical bomb I was holding and spent a lot of time rinsing out the spray bottle before filling it with the acid.

Actually, the degreaser worked pretty good on the yuck under the truck and cleaning the grease out of the shop rags. I might have to get some more of that.



We start with a hot tanked brake backing plate with some surface rust.

Spraying it starts the rust running off, metal begins to get shiny..

But only the surface rust come off. Nothing with any depth at all seems to be effected.

Hmm..



The light rust came off and I rinsed off the acid. Rinsed it really well. Used baking soda and the toxic degreaser on it.

An hour later the entire disk had started turning yellow.

Oh no! I'’d done both backing plates and all four brake drums!

As the day wore on, everything got rustier and rustier!



What to do? I threw in the towel and took the entire set to the powder coaters. “Can you sandblast off the rust and powder coat all this mess? Will the powder coat work on brake drums?”

Andy the powder-coater, “No problem!”

These guys can do magic.

And that puts painting parts off for another day.



Checking the seat pieces while I’'m there. After I’'d welded up the frames, the upholstery people repaired the spring stuff and fixed whatever needed fixing on them.

The jump seat tended to sort of lean you over and out of the truck. Somewhat like sitting on a beachball. I checked and they’d added a kind of sway bar inside the spring set. How cool!

Then they were shipped back to Andy’s powder coating shop. Everybody around here uses this shop. Skagit Powder coating. Very popular with the locals.



Pink rims. I finally had to break down and do some painting. Last time I couldn’t see where I was painting because grey primer is the same color as sandblasted steel. So, I asked for red primer. When I was a kid people had red primer. I guess its not cool anymore, they only had grey.

“Well, can you pour some red pigment into the grey primer for me?” And that stopped them.

“You want me, to put pigment, in the primer?” No one ever understands when I ask for something just a little bit different. As you can see, in the end, I got pink primer. And it worked great.



The next day I shot them with the olive drab. I was able to let them dry all day on the line before bringing them into the garage to dry in the warmth. That night the first rains came. I made it just in time!



Turns out that this paint I’m using needs to dry, not just overnight, but over two nights to get really hard. I had the last batch mounted too soon and some of the paint was scratched off. These I let dry for two nights and they went together much easier.

The local Les Schwab tire center does these for me. I was telling them that I’'d brought in some tires to be mounted and they asked if they were more of my army truck tires. “Oh!” I figured they’d not remember, with the massive flux of customers going through there.

But then I started thinking about it. I’'ve brought them thirteen tires to be un-mounted. They were successful with twelve. Then I brought them ten tires to be mounted. And it turns out, I’'m the only customer that has them do tires like this. I guess that’s why they remember. I should drop by and give them a ride in the truck some day, as a small token of my gratitude.



Meanwhile back in the garage..

Remember last installment we left off with not being able to get the Trunnion bearings preload set correctly. (The bearings that the wheels turn back and forth to steer on.)

We’'d gotten to the point where putting the smallest shim onto our shim stack would set the bearing preload too tight, whereas swapping for the second smallest would set it too loose.

What to do?

I spent time doing other things while I thought about how to solve this. A lot of plans involving micrometers, computers, database, scary math and sorting algorithms were pondered. And then, just this afternoon, it came to me. “Duh! Put the second smallest in there making it close but a little loose. Then, sand the thickest shim from the stack (strongest, easiest to work with) ‘'till the preload comes into spec.



I had lots of sand paper from the boat building days. All I needed was a flat surface. And here are these nifty flat topped shop stools..

I trimmed a piece of sand paper to stick to the top of the shim to make gripping it possible. And sanded away. Every minute or so I’d rotate the shim 90 deg to even out sanding variances.

Amazingly it worked!

Originally, shooting for a torque between 25-27 ft-lbs, I was getting 18-30+ ft-lbs. Now I was able to sand, check, sand, check sand, and step it right into spec.

NOTE: I ended up using 120 grit sand paper.



The plan was to just re-attach the drag link to the steering arm. (Repairing, not restoring.) The drag link was a mess. Covered in tar and road yuck. Chunks of something hanging out of it. They must have entertained themselves by driving this poor machine through hot tar on the weekends. Seems to be more than its fair share under here. And, when I pulled out the inside bits to unhook it, I found them in the wrong order.

Sigh..



Drag link out, pulled all apart and a couple days, back burner time, cleaning everything. Then, looking at the diagram from the manual, I realize that it’s not actually symmetrical. One end is further in than the other. Better keep track of that too.



After some time figuring out how the leather & felt dust covers worked, I was able to get it all back together like the picture in the book showed.

Preload set, steering arm back in place, drag link installed, tires ready. The rest of the parts are off at the powder coaters.

Next is to re-install the grease/dust wiper on the back of the knuckle then clean up and bolt on the tie rod.

Of course there’s also the passenger side to do.

This is taking forever!