Arc & spot welding
Automotive hand tools
Car enamel colors
Car paint colors
Car paint glossary
Car painting problems
Cleaning car upholstery
Infra-red paint drying
Interior automotive trim
Painting over paint
Paint surface preparation
Refinishing paint tips
Safe car spraying
Sanding, striping, rubbing
Shrinking sheet metal
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Users of oxyacetylene torches should properly protect their hands against contact and radiation burns. Gauntlet gloves are recommended to provide protection for the wrists. The material should be wear-resisting and not easily burned. Cotton fabric gloves, untreated, are dangerous and should never be worn when welding or cutting. The best welders' gloves are made of first quality horse-hide. Asbestos gloves are used in welding heavy preheated jobs and cutting risers from hot steel castings.
Fluxes are used in welding cast iron, brass, bronze, aluminium, nickel, monel, and the non-ferrous alloys in general, but are rarely or never required in welding low-carbon steel.
A flux is essentially a deoxidises. Low-carbon steel requires no flux because the oxide sometimes produced in welding remains in a molten condition.
But cast iron and the non-ferrous metals are welded at lower temperatures, and their oxides as a rule remain solid and tend to mix with the molten metal. Hence, the desirability of cleansing the metal with approved flux.
Airco-Atlas Cast Iron Flux is recommended for welding cast iron, and Airco-Marvel Welding and Brazing Flux, for welding brass, bronze, and copper and for brazing cast iron, malleable iron, and steel; Airco-Matchless Plate and Cast Aluminium Flux for aluminium plates and castings; and Airco-Napolitan Sheet Aluminium Flux for sheet and cast aluminium and many aluminium alloys.
The mechanical or physical properties of fluxes are important as well as their chemical properties. Intimate mix, proper proportions, and purity are essential to the best results. Fluxes should be kept in closed containers when not in use and should as a rule be used sparingly for the best results.
Special asbestos paper is used to cover castings when being preheated and welded, and while cooling down. Asbestos being an excellent non-conductor reduces the heat radiation and protects the operator; it shields the cooling casting from drafts and prevents rapid local cooling with consequent contraction stresses and danger of cracking.
The fragments of used asbestos paper make excellent packing for annealing steel forgings, dies, and tools.
Carbon blocks and rods are indispensable in building up shapes such as gear teeth, lugs and bosses on castings, and to protect threads in tapped holes. Carbon blocks and rods withstand the high temperature of the oxyacetylene flame. They are readily sawed and shaped with tools to any form required, and rods of correct diameter can be screwed into tapped holes, thus giving full thread protection.
The operator should dress in appropriate clothing for welding. A one-piece loose-fitting overall suit with button wristbands and close-fitting collar is recommended. Gauntlet gloves of good quality properly fitted and extending 2 or 3 inches above the wrists protect the hands and forearms from the heat. High, laced shoes with thick soles and sound. uppers are desirable to prevent burns from flying sparks and molten metal. Head covering is optional. Many welders wear a thin cloth cap, and turn the visor backward in a measure to protect the neck. The goggles and spark lighter have already been mentioned as highly desirable if not indispensable parts of the welder's costume and outfit.
Suitable wrenches for setting up regulator nuts, connecting hose and changing torch tips are necessary parts of every operator's equipment. Use of pipe wrenches and unsuitable screw wrenches should be prohibited. High-grade small screw wrenches are permissible, but drop-forged wrenches with openings closely fitting the regulator nuts and hose connections are recommended. If loose-fitting wrenches are employed the nuts will be damaged, soon making the equipment unsightly and possibly requiring replacements.
The cylinders of welding and cutting outfits should wherever possible be used in an upright position to protect the regulators and to insure the best results as regards quality of acetylene and convenience of operation. A two-wheel truck especially designed to carry an oxygen and an acetylene cylinder is desirable with all portable outfits. The truck has chains for holding the cylinders in place.
The beginner should practice setting up and connecting the torch, hose, and regulators in a certain order. The sequence of operations following is recommended because it follows a logical order, assures safety, and eliminates unnecessary movements.
Roll the cylinders on to the truck and chain them fast. Remove the valve caps and examine the screw threads on the outlet nozzles. Do not attempt to use a badly bruised screw thread or connection seat. A damaged thread is likely to spoil the regulator nut, and a jammed seat will leak. Damaged valves are a result of leaving off the valve caps in transit, and the damage generally happens after the cylinders have been turned over to the user. Co-operation to prevent damage to cylinders is always to the user's benefit.