Cracked exhaust manifold

[fordfun]

I removed my manifolds to correct an exhaust leak, and found that the waffle section of the exhaust manifold has a crack in it. I had planned to sandblast and repaint all of these units if they are salvageable. I'd appreciate any help you can give me with these questions:
1 - Is the waffle section hollow and connected to the exhaust chamber? If not, I'm wondering whether I can just ignore the crack and proceed with refinishing.
2 - If it is connected to the exhaust chamber, can it be sealed in some fashion?
My concern here is that I suspect replacements for this type of manifold are not available so without it the Auto-Lite heater unit may not be usable on the replacement exhaust manifolds that are available.

I believe the exhaust leak was coming from a disintegrated copper gasket, both of which will be replaced.

Thanks for any help you can give me.

 

[Fullraceflathead]

You might try brazing it.

 

[pgerhardt]

I am no expert here, but picture #3 shows a hole in the heat exchanger very close to the crack. It doesn't look hollow to me. If solid one approach who be to drill a 1/8" hole at the end on the crack to prevent it from spreading and just check it each spring when you pull the heater off for the summer.

 

[Patrick L.]

I have a few just like it, well, hopefully without the crack. I don't believe they are hollow and yours doesn't seem to show any signs of being hollow and blowing any exhaust through it. The hole is to allow access of the distributor set screw. Braze it, weld it, drill it, whatever you want to do. I don't think I'd worry about it.

 

[JonC]

I had a similar issue a week ago and ended up brazing my maifold, It looked good but I guess the warpage that caused my crack was too much so I ended up buying a new repop. So the good news is brase worked in my case but warpage did it in.

 

[Bulligen]

The waffle design on the top is not open to the the exhaust gases as you can see by evidence of the hole for the distributor set screw. You do not have to worry about the safety of fumes gong into the passenger compartment. I would leave the crack alone just sand blast it and paint it and off you go!

 

[fordfun]

Thanks for all of your responses. I'll clean up the various pieces and proceed to painting them.

Bill

 

[WestCoast]

I Would drill a small hole at each end of crack, say about an 1/8th", v the crack a 1/4" wide and an 1/8 " deep, heat the part and braze, let it cool slowly