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I Forge Iron

Can't find it


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Hi everyone,
I give my apologies up front. But I searched for a certain thread and didn't find it. Some time ago I saw a thread on how to find out if truck leaf springs are cracked or not. I remember that there were several steps to it, but one of them was to spray white paint on them to help reveal any cracks. I am trying to get my forge set up again after our move to our own home this summer (our first home :D ) and I have some broken semi truck leaf springs out in the scrap pile. Since they are already broken, I would like to check for any other cracks before I start heating and pounding and having hot steal fragments flying in all directions from a shattered piece. This may be a rather ambitious idea for my skill level, but I would like to make an axe out of a piece of it. Any help you can give would be wonderful.

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Glenn is right on the one method of detecting the crack. It involves a u shaped electromagnet that is placed against the surface of the steel. Then you sprinkle iron powder on the steel between the poles of the magnet. If there is no crack the iron fillings just line up evenly between the poles of the magnet in the classic pattern. If there is a crack, then the filings line up as if there were four poles instead of two and you will see the line of the crack between each set of the two additional fields. Basically two separate magnetic fields with the crack as the dividing point.

Another method involves a special die and developer. The die is first sprayed on the steel and allowed to soak. It will penetrate into any cracks in the surface. Then a developer is spray on and the die will change colour. Any cracks will have a lot more dye than the surface and will be a lot more intense in colour and will show up quite clearly. I am not sure where you could get the dyes but if you did a search on "Non Destructive Testing" on the net I am sure there will be plenty of suppliers that would show up.:)

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