Welding Stay Bolt Sleeves

The two images here are close ups of electric arc welding being used to restore damaged flexible stay bolt sleeves on the 2926 boiler, one literally accurate, the other taken into the abstract. Over a thousand flexible stay bolt sleeves have to be replaced due to rust.

Arc welding uses an electric arc to heat the boiler metal and the arc rod metal to create a puddle of molten metal on the boiler. Deposits of molten arc rod are carried in the arc into the puddle to form the weld. The process will build up a new layer of filler metal as needed. The heat of the arc vaporizes a chemical coating on the arc rod to create a plasma shield to keep atmospheric oxygen from attacking the molten metals. The ragged white area in each image is the plasma shield. You can also see the smoke from the rod coating and trails left from tiny particles of molten metal commonly referred to as splatter. The welder must maintain and direct the molten puddle created by the arc by constantly feeding arc rod into the weld, so these images are “action” photos, thus the double imagery of the leather glove in the right hand image.

The images were both shot with a zoom telephoto lens from a distance of 15 feet so I was not risking eyes or optics (crazy yes, stupid no). Digital cameras have a significantly narrower range of sensitivity to light than photographic film. To compensate, a process has evolved called HDR or high dynamic range photography. Three images were rapidly made of each shot, each taken at different exposure values, the detail unique to each exposure was blended with the other two to capture as much detail as possible in a single image for each shot.

The close up image set above shows a silhouette of an eroded stay bolt sleeve in the foreground. It will be restored by welding layers of new metal over the eroded outer housing after the rust is ground off.

Behind the arc and slightly to the right you can see where a new replacement sleeve is being welded in place. The new sleeve is made larger to fit over the damaged sleeve that was too eroded to be saved. Around the base of the new stay bolt sleeve you can easily see the layers or “beads” of filler metal created when the drops of molten filler metal froze in the puddle.

The image set below shows a larger area of the boiler with the welding cables, some of the welders gloved hand, and many more stay bolt sleeves. When I finished processing this HDR image set, it had an interesting flare pattern created by the optics of the lens. This image felt too dark and would only distract from the close up image. My curiosity got the best of me so the process of “what happens if I use a little of this and maybe a little of that will look good” took over. In Adobe Photoshop the options are endless . . .

Photos Copyright 2014 by Ron Taylor