Matt in NY Posted January 5, 2009 Share Posted January 5, 2009 Cracked right through the firepot on both sides of the grate. The gap is probably an 1/8 inch. What to do? Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 5, 2009 Share Posted January 5, 2009 How good are you at welding cast iron? If not skilled enough to take a shot at it yourself you can splint it with strap steel screwed to it across the crack. Before you do anything drill a stop hole at the end of the crack to keep it from running further. Frosty Quote Link to comment Share on other sites More sharing options...
Lysdexik Posted January 5, 2009 Share Posted January 5, 2009 Stop holes are a life saver on cast. Frosty, would you weld with Hi Ni rods? I have torch welded them with broken piston rings as filler, but never had a go at "Old Sparky". Do you pre heat? Paul. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 5, 2009 Share Posted January 5, 2009 Yeah, drill stop. Grind cracks till they're good and clean well beveled where closed. Make a fire with charcoal briquettes and lay the forge pan over it and preheat to around 400-450. Weld with Hi-Ni 98%+ rod at recommended amperage, I do this so seldom I have to check every time. Weld in short passes, 1" weld, 1" gap (called it skip welding when I was a kid and for the life of me I can't remember what it's called now) Or splitting the gap, 1" weld at each end of the crack starting with the widest, then 1" weld in the center, then 1" weld centered in each gap, etc. till closed up. Ping and relieve. Leave it on the fire at 400-450 and bury in ashes or perlite and come back in the morning. Wrapping with Kaowool if you have enough works too but leave the fire going. Cross your fingers when opening it up after it's cool. Oh yeah, holding your tongue just right while welding is imperative! Frosty Quote Link to comment Share on other sites More sharing options...
ironrosefarms Posted January 5, 2009 Share Posted January 5, 2009 (edited) My rivet forge was cracked when I got it, I drilled a stop hole and put a piece of strap at the same thickness as the cast iron across and bolted it on. This has held for about 12 years many of which was aggressive years of forging. I did not attempt to weld it, this repair was cheap, easy, and doesn't have as much luck required in it... What I have noticed is when I'm bringing the forge up to forge welding temps for very long the crack would "swell" open slightly but the strap would "swell" with it and did not cause further breakage. James Edited January 5, 2009 by ironrosefarms Quote Link to comment Share on other sites More sharing options...
Matt in NY Posted January 7, 2009 Author Share Posted January 7, 2009 The crack is all the way through; cracked in half, but is still very stable. It has 4 holes that are designed to hold a heat shield. (I know right where we left that sheild too. Covered a hole that was dug to put in a telephone pole 35 years ago. Never got the pole up and my folks moved. I convinced them that I had a use for the forge though so they brought it to the new place; my Grandfather's place a mile away.) I'm thinking of making a ring around the top and bolting it in place using those holes to bolt it on. I know I'm not up to that yet. Then I figured I could bolt a couple straps in toward the grate. Maybe have somebody fill in the rest by braizing. Quote Link to comment Share on other sites More sharing options...
Thomas Dean Posted January 7, 2009 Share Posted January 7, 2009 The crack is all the way through; cracked in half, but is still very stable. It has 4 holes that are designed to hold a heat shield. (I know right where we left that sheild too. Covered a hole that was dug to put in a telephone pole 35 years ago. Never got the pole up and my folks moved. I convinced them that I had a use for the forge though so they brought it to the new place; my Grandfather's place a mile away.) I'm thinking of making a ring around the top and bolting it in place using those holes to bolt it on. I know I'm not up to that yet. Then I figured I could bolt a couple straps in toward the grate. Maybe have somebody fill in the rest by braizing. I would bolt straps as mentioned above and use a straps around the bottom as well. I would not braze up the cracks, no need, the straps will do the job with no problem. Brazing would be a waste of brass and gas. I have a cast forge that I use for demos repaired this way. (see photos in my gallery) I had a forge several years ago that had been welded/brazed by the previos owner. First fire I built in it I heard that distinctive POP when it broke at the repair. The previous owner "repaired" the pan but never had a fire in it. I straped it and had a year or 2 of forging before I sold it. It was my first (and only) forge at the time. Quote Link to comment Share on other sites More sharing options...
Matt in NY Posted January 8, 2009 Author Share Posted January 8, 2009 Sounds good and thanks to all. I hope to have this forge for some time. It was my greatgrandfathers Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 8, 2009 Share Posted January 8, 2009 I should've been clearer. Just because I could weld one up (probably) successfully doesn't mean I would. I'd put the strap splints on it if given the choice. I'd never try brazing a casting this size without a brazing oven. Even then there're no guarantees when you build a fire in it. Frosty Quote Link to comment Share on other sites More sharing options...
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