Birdsall Marine Rides Perfect TIG Wave Featured In “Manufacturing Engineering” Magazine
February 15th, 2008
What started off with Bob “Big Bob” Birdsall Sr. building hot rod and boat componets as a hobby more than 25 years ago has grown into Birdsall Marine Design, a 27-person company located in West Palm Beach, FL.
Birdsall’s more than 100 distinctly crafted marine products adorn boats around the country. Boats owners from as far as North Carolina and Puerto Rico bring their boats in to receive the Birdsall touch. Weather the boat is involved in competitive sport fishing or just used for weekend recreation, Birdsall has the products and skill to customize or restore it.
“We manufacture different designs and perform as the fabrication that goes with our T-tops, leaning posts, towers, deck towers, rod holders, and back rest arms among many other different items,” says Bobby Birdsall Jr., company vice president. Birdsall evan has its own in-house machine shops, allowing them to perform all the tasks needed for custom jobs.
Anodized aluminum is used for about 85% of its products. Although anodized aluminum offers corrosion resistance and good appearance, it adds a level of complexity to the welding process, which until recently, doubled the welding time. Introduction of the Dynasty 350 AC?DC TIG inverter from Miller Electric Mfg. Co. (Appleton, Wi) has made the job easier and faster, cutting the welding time in half.
“Next-generation advanced square wave technology has cut welding time in Half.”
Anodizing, which closely resembles electroplating, converts the aluminum surface to aluminum oxide, which can vary from 0.0002 to 0.001″ (0.005-0.03-mm) thick. This coating is hard, dense and nonconductive. Unlike the rust on steel, aluminum oxide protects the base metal, providing increased corrosion resistance, excellent wear and abrasion properties, and a wide range of decorative finishes. Color varies with the thickness of the coating.
Very few welding operators can develope a technique and a machine that lets them manipulate the AC TIG arc so that it pentrates the anodized coating establishes a good weld puddle without adding so much heat that the puddle rolls out of the jointor the arc blows through the base metal.
However , aluminum oxide meltsat approximately 3600 degrees F (1982 degrees C), while the aluminum underneath melts at about 1200 degrees F (648 degrees C).
“When I first started welding, Iwas told you coudn’t weld anodized aluminum that you had to remove the anodization first,” says Bruce Sadd, Birdsall fabrication manager. Sadd started using a technique called “backing around weld,” which alowed him to weld the material without first removing the coating. In backing around the weld ,” which allowed him to weld the material without first removing the coating. In backing around the weld, the operator first directs the torch in one direction to heat up the material and disperse the anodization to each side of the puddle. Then the operator makes a pass in the opposite direction to actually perform the weld.
This technique takes a skilled welder and doesn’t leave room for error. Too much heat can burn or warp the component and cause it to be scrapped. “You get one chance to make a weld with anodized aluminum,” says Bob, Jr. ” You can’t go back and sand it or do much else to it to make up for a bad weld. The appearance would suffer.”
To perform their jobs, Birdsall’s seven welder/fabricators use a variety of Miller TIG machines, from a 23-year-old AB/P 330 to a previous Dynasty model. When Saad was recently asked to test a new Miler Dynasty 350 AC/DC TIG/Stick welder, he found out how easy welding anodized alumnium could be. The new Dynasty allows him to make the weld in one pass, not two. There is no longer any need to back around the weld. This saves 50% of the welding time and puts less heat into the weld , making it less likely to damage the component being welded.
