[SEL] Fairbanks Morse ZD Cracked Block - Best Way to Repair

[fero_ah at city-net.com]

Hi Folks,

Let me add a couple of thoughts to Tommy's JB Weld comments.  I've also had
great success with doing water jacket crack repairs using JB Weld.

Tommy's observation on the fluidity of JB Weld can be a blessing or a curse
depending on the nature and geometry of the crack / hole that you're trying to
repair.

The normal version of JB Weld (two-part in tubes) is actually fairly fluid, even
at room temperature.   That means you can get penetration into the crack (a
good thing) but it can also run out of the crack and down the block (not a good
thing).  http://jbweld.net/products/jbweld.php

For some geometries where the crack is vertical (and you can't lay the block
over) you might want to consider JB Stik.  Since you knead this stuff, you can
shape it and press it into place to add lots of options to the repair process. 
http://jbweld.net/products/jbstik.php

Finally, be aware of JB Kwik http://jbweld.net/products/jbkwik.php.  No engine
man's toolbox should be without this product for rally field repairs.  It can
make the difference between having a stationary engine or a runner for the
weekend!

See ya,  Arnie

Arnie Fero
Pittsburgh, PA
fero_ah at city-net.com

Quoting Judge Tommy Turner <lcjudge at scrtc.com>:

> JB works well and I've used it numerous times and can't remember not 
> having a good result.  Here's a few tips though to make sure others have 
> success also.  One is to make sure that the surface where the JB is to 
> be applied is free of dirt, loose paint, etc.  I usually take a die 
> grinder and try to "V" the crack.  It doesn't have to be wide or deep, 
> maybe 1/8 inch wide and a total of 1/16 to 3/32.  Then, after I vee it 
> out, I take some carb cleaner and spray the crack real well.  This will 
> help remove oil and grease that may be down in the crack.  Finally, I 
> apply a little heat.  Not a great deal, but hot enough that you can't 
> hold your finger on it or that its just hot enough that if you spit on 
> it, it would sizzle.  I've even repaired some (the 4 HP Columbus I've 
> got for one) with original paint and haven't burned it off.  You've got 
> to be patient.  The heat will do three things, one it will further 
> ensure that grease, oil, etc that may be in the crack will be driven 
> out.  Two, the heat will cause the crack to open a bit (maybe only a few 
> thousandths or two but that will be enough for the third thing it 
> does).  Three, heat will cause the JB to run like water.  When you apply 
> it to the heated crack, it will run in the crack to ensure you have a 
> good seal.  As I say, I've done this several times and its never failed 
> to seal the crack.  I even used this once on a small internal cylinder 
> crack that was around the rear of a cylinder.  I ran the engine for 3 
> years at shows after the repair and it never leaked.