[Farmall] Another O-12 project, part 5

[Karl Olmstead]

Spent hours and hours sandblasting today.  Still lots of parts to go.  Nowhere near painting yet.

Drilled out one broken bolt in the top radiator tank.  I finally got one right.  Never even nicked the original threads, and the drilled-out bolt came out as a little coil.

This particular O-12 has the screwed-on aluminum McCormick-Deering medallion on the radiator top tank, and both screws were stuck tight.  I thought about grinding the screw heads off in order to get the medallion off, but then I decided to try heat.  I knew that I couldn't use a torch on the heads of the screws; the flame would melt the thin aluminum medallion almost instantly.  So I heated up the bulges inside the radiator top tank, the extra material added so that the screw holes wouldn't penetrate the cooling system.  Had to spread the heat out; too dangerous to heat just a small spot on a casting.  To my amazement, the stuck medallion screws came loose easily after heating the top tank.  There's no doubt in my mind; heat is enormously more effective than any penetrating oil.  Just for fun, I heated up the nut on the radiator cap.  It, too, unscrewed easily.

I did set up an electrolysis system.  In keeping with my philosophy that 'anything worth doing is worth doing to wretched excess', I souped up the electrolysis process a bit.  I used a fairly large plastic tub and the first part to go in was the top radiator tank.  In order to make the water more conductive (and get those electrons flowing), I dumped a can of lye in the solution.  This does two things.  Sodium hydroxide makes a fine electrolyte, and it also chews off any grease or paint left on the parts.  Good chance to use my new battery charger.  Jacked up the voltage until I the meter was showing ten or fifteen amps of current.  That'll reduce some rust!  Should be done tomorrow.

No point in starting to paint until I'm done electrolyzing and sandblasting.  Quicker and cheaper to do the painting all in one batch.  To my surprise, this tractor seems to have been red right from the factory.  I'd been expecting to see gray paint, but all I found was two coats of red; a decent layer of original paint, and a really cheap, faded topcoat.  Serial number makes it a mid to late 1936 tractor; well before the official changeover.

The reason I'm sure it was red is that the front axles, inside the front hubs are red.  The tractor desperately needed new front tires; I'd been stalling on pulling the front wheels because the O-12 doesn't have rims.  Pulling the wheels means messing with the front wheel bearings.  I hate wallowing in 70 year old wheel bearing grease!  And now I have to find new seals.  After pulling the front hubs and driving out the bearing races, I used my backhoe to break the tire beads loose from the wheels.  I'll haul them into town tomorrow and get the tires taken off.  Then the wheels go on the pile of parts needing cleanup, sandblasting and painting.  Need to look up what 6.00 x 16 equates to in a modern tire.  Wonder what kind of tread the O-12 front tires originally had.  Two or three ribs?  All I ever see on them is old, bald car or truck tires.

Nowhere near the 'golden moment of turnaround' yet.  Parts are still coming off; nothing is going back on.  And this isn't a full restoration, just a preliminary fixup in order to create a useful tractor.  Full five-day workweek coming up; I won't be reporting in for a while.

Thanks for all the comments and suggestions!

-Karl