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I've been temped to try this (soooo convenient...) but always chicken out. You've inspired me!
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Successfully welded cast iron
- Thread starter Braeden P
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But what difference in mechanical properties would you expect to see given that it is present as a fine powder? (I haven't noticed any graininess when using JP) It is there as a filler. It would be easier to make a fine powder from cast iron than steel but from a marketing perspective, epoxy steel has a nicer ring to it than epoxy iron.
But... The reason I chose to use "iron" rather than "steel" in my original post was that @Braeden P indicated that he was planning on adding cast iron dust to the JB Weld.
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The resin is slightly magnetic. The hardener isn't. There isn't enough iron present to provide a conductive path. I expect that the white color is the calcium carbonate filler listed in the MSDS.
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I have used steel welding rod to repair a cast iron manifold in the past. The primary issue is dealing with the brittleness of the white cast iron created when the weld interface cools. White cast iron is glass hard and glass brittle and as the weld cools, the metal shrinks and the less ductile cast cracks, If the part is heated to a red heat and allowed to cool slowly, the cast will become ductile gray cast and cracking is less likely.
I don't use the this when the part requires tensile strength but in compression, it does the job. I also don't use it when the repair is fighting a larger, more complex part of the casting where the thermal shrinkage creates stress. In my experience it works better than using nickle rod and peening the weld.
I use this process whenever welding any steel that contains a significant amount of carbon to prevent cracking at the weld site.
I don't use the this when the part requires tensile strength but in compression, it does the job. I also don't use it when the repair is fighting a larger, more complex part of the casting where the thermal shrinkage creates stress. In my experience it works better than using nickle rod and peening the weld.
I use this process whenever welding any steel that contains a significant amount of carbon to prevent cracking at the weld site.
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Do you guys live here in the USA? I mean we are the most litigious society (if you can call it that) in the world. Do you think JBWeld would risk IRON for Steel??? in this environment. I take it at face value, that it's steel (an alloy of iron and carbon and whatever else they decide to add).
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If this is a part under some stress, you'll probably see it fail. The carbon in the steel diffuses into the iron to give you an extremely brittle interface. CI CAN be welded with steel rods - I've done it like this before, too, but it's not optimal. By heating the piece like you did, the carbon may have diffused enough to really minimize the brittle region. Usually, CI is welded with a nickel based, zero carbon rod, so there is no carbon present to create the brittle area.
What does this part do on the shaper?
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Cast iron already contains 2 -5% carbon. It is the rapid cooling that makes it brittle. Essentially, it creates white cast iron in the heat affected zone. Heating and slowly cooling will anneal the heat affected zone, forming grey iron.
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This picture should help, I’m not good at describing.
It will only be in compression not tension so it should hold up.
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Looks great Braeden
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I’m finishing up scraping a 15x18” surface plate to scrape every part flat, it’s gonna look and work a lot better soon.
