Musings from a Military welding manual part 4
Part 4 to Musings From A Military Welding Manual I found from 1943.
How have times changed! The list of stick welding electrodes found in the War Departments 1943 issue of their Welding manual is quite short and thin. Though Stick (Shielded Metal Arc) welding was already well established as a welding for in the 1940’s the typical classifications we enjoy today with readily defined classes of electrodes made to a central standard was not quite so organized. The welding manual records 3 basic classes of welding electrodes: Bare, thinly coated, and heavy coated/shielded arc electrodes. It gives little discussion of the use of the bare electrodes. Obviously we know why now, with impurities, and arc instability problems that would be present, but it is curious that they would even devote a paragraph to the possibility of use of such an electrode. When I began reading the discussion on thinly coated electrodes, I suspected it would be a discussion of cellulose based electrodes. However, it surprised me that the electrodes in discussion were iron powder/titania based and would produce little to no slag. Their application would: 1) “Dissolve or reduce impurities such as oxides, sulphur, and phosphorus”, 2) “ Reduce the adhesive force between the molten metal and the end of the electrode…..making the flow of molten metal uniform and continuous” 3) “..Increase the arc stability by introducing materials readily ionized (changed to particles with an electric charge) into the arc stream.” I was held in suspense about this welding rod. I was wondering if this was an early version of a 7014 or a 7018. But the light coating and the “quite thin slag” does not seem to comply with modern manufacture of this electrode. The Shielded Arc (Heavy Coated Electrodes) were divided into TWO TYPES! The manual introduces the class of electrodes to say “ Shielded-arc or heavy coated electrodes are easily identified by their heavy extruded coatings.” Then it quickly breaks them into two basic types with an additional suggestion of a blending of the types. “The cellulose coatings and miner coatings, and combinations of both.” “The cellulose shielded types are derived from wood pulp, sawdust, cotton, or more recently from various compositions secured from the manufacture of rayon. The mineral-coated shielded types are manufactured from metallic oxides, which are often used in the form of natural silicates such as asbestos, and clay or in specially manufactured forms of silicates. Other materials for electode coatings are burnt sugar, gums, starches, and certain low melting point spars. The cellulose rods certainly do sound like modern 6010 or 6011’s, but the other classification with straight silicates do not sound familiar, especially asbestos…though I was aware that it had been a common part of welding rod material years ago. These rods were used to hold things together back them, no doubt many of the structures and machines made with them still in existinence, if not rotting in the weeds in some long lost jungle back then, so they must have been viable ways to weld, even if their health consequences were a little suspect. This section is chock full of tidbits and interesting notes about the composition and purposes of the electrode, but in looking over this I am glad that modern research and technology has been employed to make the modern classes of electrodes such as the E 6010, E6011, E7014, and E7018, not only to make our electrodes better suited to the task of welding, but also somewhat safer, though that is still a legitmate question in everyone’s mind about fumes and dust created by this process even today.
Look for our final installment of musings from a military welding manual next week.