[SEL] Fairbanks Morse ZD Head Repair Information Needed

[John Culp]

I had to remove some J-B Weld that had been applied to a cylinder wall 
to fix wrist pin gouges and hadn't been properly smoothed down. It 
looked good, but the high spots kept the rings from sealing. I got it 
out with a propane torch, but I had to get it HOT before it weakened 
and softened. Finally got chalky and could be chipped and brushed out. 
I was starting to worry about cracking the cylinder wall with the 
intense heat. When I replaced it afterward, I figured out a better way 
of getting a really smooth, level surface. Instead of rolling the 
surface of the fresh J-B Weld down smooth with something like a can (as 
I'd seen recommended on here), I applied it, let it thicken up for a 
few minutes, then took a piston ring, oiled it so the stuff wouldn't 
stick to it, and pushed it straight down the bore with the lightly 
oiled piston till it popped out the other end. Instant perfectly smooth 
bore surface!

In a "hot" head with no water jackets, the J-B Weld might get hot 
enough to break down. But I don't think it will in a combustion chamber 
wall adjacent to cooling water.

John Culp
Bristol, Tennessee, USA