Top Gun 351 SWF, Руководство пользователя

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Electrode Wire Size Selection
The choice of Electrode wire size and shielding gas used depends on the following
• Thickness of the metal to be welded
• Type of joint
• Capacity of the wire feed unit and Power Source
• The amount of penetration required
• The deposition rate required
• The bead profile desired
• The position of welding
• Cost of the wire
A Word to Beginners
For those who have not yet done any welding, the simplest way to commence is to run beads on a piece of scrap plate. Use a mild steel
plate, around 6mm thick and a 3.2mm electrode. Clean any paint, loose scale or other contaminants from the plate, and set it firmly on the
workbench so that welding can be carried out in the downhand position.
Make sure that the work clamp is making good electrical contact with the work piece, either directly or through the work table. For light
gauge material, always clamp the work lead directly to the job, otherwise a poor circuit may result.
ARC Welding Technique
The Welder
Striking an arc
Place yourself in a comfortable position before beginning to weld. Get a seat of suitable height and do as much work as possible sitting
down comfortably. Don’t hold your body tense. A taut attitude of mind and a tense body will soon make you feel tired.
Relax and you will find that the job becomes much easier. You can add much to your peace of mind by wearing a leather apron and
gauntlets. You won’t be worrying then about being burnt or sparks setting your clothes alight.
Place the work so that the direction of welding is across, rather than to or from, your body. The electrode holder lead should be clear of any
obstructions so that you can move your arm freely along as the electrode burns down.
If the lead is slung over your shoulder, it allows greater freedom of movement and takes a lot of weight off your hand. Be sure the insulation
on your cable and electrode holder is not faulty, otherwise you are risking an electric shock.
Practice this on a piece of scrap plate before going on to more exacting work. You may at first experience difficulty due to the tip of the
electrode “sticking” to the workpiece. This is caused by making too heavy a contact with the work and failing to withdraw the electrode
quickly enough. A low amperage will accentuate this. The freezing-on of the tip may be overcome by scratching the electrode along the
surface of the workpiece in the same way a match is struck.
As soon as the arc is established, maintain a 1.6mm to 3.2mm gap between the burning electrode end and the parent metal. Draw the
electrode slowly along as it melts down.
Another difficulty you may encounter is the tendency that after the arc is “struck”, to withdraw the electrode so far that the arc is broken
again.
A little practice will remedy both the aforementioned faults.