cracked fire pan repair

[Bo T]

Just got some blacksmithing tools from a seller. One item is a cast iron coal (fire) pan for a forge. I'll need to put in a tuyere and ash dump and the air inlet. There is a crack in the pan running about 2/3 of the way from the outside edge to the hole at the bottom (2 or 3 inches from the hole). I've never repaired cast iron. I'll put an inch or so of refractory in the pot before using. I've read that there is a nickel rod that will work with an arc welder on the cold iron. I've also read that brazing is pert near as strong. I've also read about something called castalloy that can be used at propane torch temperatures. The iron appears to be @‌ 1/8" thick. I did some oxyacetylene welding in my youth. I've never brazed or arc welded although I am thinking about learning some stick welding. Do you guys think brazing or castalloy will hold with the refractory protecting it from the heat? Would MAPP or propane get the thin iron hot enough for higher temperature brazing? I don't mind coming out a little upside down on this as I consider it a "learning experience". On the other hand, I still need to buy beans and potatoes. And I'd like it to work. 

[wpearson]

on that forge i would bolt a piece of steel over or under it

[ironwolfforgeca]

Steve's Welding here -- I Hate cast Iron !! but it can be welded ?? depending LOL-- I have done enough over the years

MY thought Trash the cast Iron Its not worth the fix !! make forge outa steel !! you're better off ! cast WILL crack again !

If you want to fix it -- Braze It ! that learning curve is easier than arc welding Unless you can weld ? THEN theres the Prep

Like I said steel is better & then you're done !

[BIGGUNDOCTOR]

I agree with Steve. I have also done a bit of cast repairs when I had my shop. Some grades weld really nice, some are non weldable. Brazing is a surefire fix. I don't like the E99 rods, I preferred the higher grade rods, but they run around $50 a pound. Then you have the preheating, welding, peening the welds as they cool, grinding, welding, peening, repeating several times,........post heating, and then the slow cooling in an insulator like gray wood ashes, then checking it the next morning to see if it all held together.

What condition is the rest of the pan? Pics?

[arftist]

Some cast can be welded some can't. Candidates for unweldable include pieces which have been burned too hard for too long. 

2. You don't know how to weld but you want to weld cast iron? No, you are wasting your time. Way too many ways to go wrong.

3. You want to braze a firepot? Nope. You can do it, then watch the pretty gold colored stream when it melts out. Don't care about the clay, too close to the fire. 

Best answer so far is bolt a piece of steel over it, unless you provide pics which show otherwise.