How to Weld: Metal Identification Basics

By Andrew Pearce
Published on November 8, 2012
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“Farm and Workshop Welding” by Andrew Pearce instructs the novice metal worker on how to weld, cut or shape metal — a practical guide to have around a homestead. 
“Farm and Workshop Welding” by Andrew Pearce instructs the novice metal worker on how to weld, cut or shape metal — a practical guide to have around a homestead. 
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Blast furnaces make pig iron, which is high in carbon and impurities. Hardness and brittleness increases as carbon content goes up. Steels in the lower reaches of the carbon league are weldable on the farm. So are those in the middle, though they need greater care over rod selection, joint preparation and subsequent cooling. High carbon steels are unweldable by normal methods. Adding dashes of other elements to carbon steels gives a wide range of tougher alloy steels.  
Blast furnaces make pig iron, which is high in carbon and impurities. Hardness and brittleness increases as carbon content goes up. Steels in the lower reaches of the carbon league are weldable on the farm. So are those in the middle, though they need greater care over rod selection, joint preparation and subsequent cooling. High carbon steels are unweldable by normal methods. Adding dashes of other elements to carbon steels gives a wide range of tougher alloy steels.  
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 A sash cramp’s cast iron endplate welded to the central mild steel beam for more rigidity is an example of a job using dissimilar steel electrodes. 
 A sash cramp’s cast iron endplate welded to the central mild steel beam for more rigidity is an example of a job using dissimilar steel electrodes. 
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Surry pump’s cast steel shear plate resurfaced to near-original dimensions is an example of a job using dissimilar steel electrodes. 
Surry pump’s cast steel shear plate resurfaced to near-original dimensions is an example of a job using dissimilar steel electrodes. 

Almost anyone can learn the craft of welding, Andrew Pearce argues in his straightforward and handy guide to do-it-yourself metal work, Farm and Workshop Welding (Fox Chapel Publishing, 2012). In this excerpt from the book’s introduction, Pearce gets things started by explaining the compositions of different alloys and the properties of different metals.

Buy this book from the MOTHER EARTH NEWS store: Farm and Workshop Welding.

What Is Welding?

It’s the process of joining materials using heat. In fusion welding, joint components are heated until they melt together or are positively fused by pressure. Blacksmiths use heat and hammer blows, but here we’re more concerned with getting heat alone to do the work.

This heat will come from either an electric arc, a gas flame, or in the case of plastics, from a hot air gun. Filler is usually added to the joint from an electrode or separate rod. Non-fusion welding techniques like braze (or bronze) welding and soldering use heat too, but not enough to melt the metals that form the joint.

Metal Identification

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