Jul 29, 2009 · I attended a welding seminar years ago and the subject of how to prep cast iron for brazing came up. According to Hoyle, abrasive particles from the grinding wheel will embed themselves in the soft cast iron, contaminating the weld area. The welding rep made the comment " we haven't discovered how to weld rocks yet". Stuart

May 25, 2007 · I have an old machine that needs various cast iron repairs. All my research leads to the best fix being brazing with silicon bronze. I have a good oxy/acetylene torch setup, no TIG. I've welded and done some brazing, but am an amateur. I've done enough and watched enough videos I have no concern about technique or actually doing it.

Sep 4, 2015 · Cast iron will braze up fine with just the normal brass rods and flux. I use the kind that has the flux on the rod. I just finished a couple pump casings, both with about 14" of crack.

May 22, 2016 · There is a time and place for everything. I have Ni rod and Have welded cast iron for many years. Sometimes brazing is the best answer. Last week I fixed a flywheel for john Deer diesel engine . I brazed it. It had a worn pilot bearing hole. It was worn about 3/16 of an inch all the way around. A new one was $1150.00.

Mar 12, 2001 · Cast iron contains something like 3.5% carbon in the form of free graphite (which is why your hands get blackened if you are filing of machining cast iron). If you were to weld cast iron with carbon steel filler metal, the free graphite in the cast iron would be absorbed into the molten metal int he weld zone.

Oct 20, 2014 · The key to brazing cast iron is to get it absolutely clean first - start by cooking it to burn off any oil/paint, then grind as required to form a V joint. Grinding will leave a carbon film behind, so a trip through a cabinet sandblaster is needed to ensure totally clean cast iron.

Oct 20, 2014 · Years ago there was an excellent article in a hobby magazine on silver brazing cast iron. Preheat was somewhere around 1200 degrees and a torch was used to make up the temp difference of the part to the silver. The whole part was put sand and allowed to slowly cool. Years ago at the Engine shop, we had a welding technologies cast iron welding oven.

Oct 23, 2018 · These are very structural joints, attaching the base to a 2” thick cast iron plate, and brazing on flanges that will bolt the pieces together. I’m still not sure if gas or TIG brazing is the way to go.

Nov 2, 2023 · 1) BLUEFIRE 1/2 lb 9pcs Bare Bronze Brazing Rods Low Fume Copper Brazing Alloys Diameter 1/8” Length 14” Solid LFB Sticks for TIG MAPP Propane Torch Gas Welding Brass Carbon Steel Cast Iron Nickel Alloy

Feb 26, 2011 · Bronze filler (depending which one you used) usually exceeds the tensile of the cast iron. Many engine castings fall in the 40,000 lb tensile range, the low fuming bronze I use has a 60,000 tensile, and a nickel silver (brazing rod) I use is 80,000 tensile. So you should be good for strength if weld cross section is same as iron.