Expert: Brad Sears - 1/19/2011

Question
Brad, I am also an "expert", but on Model A s.  I have a block with a freeze crack in it and it looks like it was repaired maybe 20or30yrs ago. I have had the car for 10yrs and three hrs ago some epoxy came loose and there was the crack. I think it was welded or grazed and then, when that failed, they put the epoxy in. It lasted a long time. I have been using marine tec or Tex , which is a neat product.  I have had to do it over twice in the last few yes. I have another engine on the way, but how can I get this one repaired?  What is the good technique you used in the past?    It runs great but I can't trust my repair. Can I trust a guy to weld it up?  
I was looking over the other experts work and thought I would ask.
Thanks, jack

Answer
Hi Jack:
Over the years the best repair procedure that I have found is the one that starts with drilling a small hole at each end of the crack. That will stop the crack from spreading. Now I have a box of tapered like pipe thread bolts, about 1/4 inch in diameter. Starting at one end of the crack drill and tap a hole so that you can insert one of these bolts. Then with a cut off wheel in a Dremil cut the bolt off flush. Now drill and tap a hole next to the first one that overlaps, install a bolt, and cut it off flush. Continue until the crack is stitched. I then coat the repair with JB Weld, sand and paint. I do not like welding on a block because of localized heat and the possibility of distortion. Once these are inserted they stitch together.