THIS OLD BUS

So, it's been a busy week.  I still have a full-time job, which really hampers the Bus renovation.  Last Saturday I had 50 yds. of fill gravel brought in to level the spot where the Bus will eventually be parked.  I leveled it out with my 1952 Ford 8N tractor (the 50's were great.  They built some good shit in the 50's.  I know.  I was there).  Monday UPS delivered a 5 gal bucket of Shell Rotella T1 50w oil.  It's one of only two recommended oils for the Detroit Diesel.  It took me two weeks to find this stuff.  As I said in an earlier post the engine takes 27 quarts.  That's 5 gallons plus 7 quarts.  I ordered two 5 gal. buckets, paid $214.00, including shipping, but only got one bucket.  I waited a couple days to see if bucket number two would show up, but not so.  I called the place where I ordered it, they said one bucket was delivered to me and the other to somebody else.  Apparently they weren't interested in five gallons of 50w oil and refused delivery.  The place I ordered from sent the other bucket out today.

I discovered a major structural failure where the left rear suspension attaches to the aluminum monocoque body.  This is a perfect example of galvanic corrosion.  Galvanic corrosion occurs when two dissimilar metals are held in contact with each other.  Moisture acts as an electrolyte between the two metals - in this case steel and aluminum.  The aluminum becomes the anode and the steel, the cathode.  Ions from the aluminum try to migrate to the steel, according to the Law of Nobility (nothing to do with kings and queens).  Steel is "more noble" than aluminum.  As the aluminum ions leave the elemental aluminum, they are oxidized - becoming aluminum oxide - a white powder.  In the photo, the big triangle piece is aluminum.  Inside the rectangle the aluminum was riveted to the steel and has corroded to expose the steel suspension arm that it was riveted to.  If you look close, you can see 6 or 7 rivet holes.  I cut off the rivet heads (not as gruesome as it sounds) and punched them out (not as violent as it sounds).  One hole is above the last "O" in corrosion.  The 6 holes inside the rectangle are what attach the suspension to the body.  Not good that the aluminum was totally gone.  Trying to weld this back together would result in a weaker fix as all the corroded aluminum would have to be cut back to solid material and then a patch welded in.  It would be very difficult to make these welds as strong as the original material.

THE FIX - First I went to my local metal supplier an bought a piece of 3/16 aluminum plate.  I then cut it to match the entire triangle of aluminum inside the riveted angle stock.

Then I sprayed the old and new aluminum with undercoating to separate the two aluminum sheets (as even with two pieces of aluminum, one is nobler than the other, and will suck ions) and to separate the steel bolts and washers from the new aluminum sheet.  Then, I bolted the sheet inside the angle stock.  The six bolts inside the yellow rectangle are the ones that attach everything back to the steel suspension components.  The rest bond the old and new aluminum sheets together.  I then sprayed everything one more time with undercoating.

WOW!  Sorry, I sorta got carried away with this little project.  Total time including getting the new aluminum about 5 hours, but I know this fix will outlast me.

NEXT - THE CONTROLS TUNNEL