Below, you will find explanations describing shielded metal-arc welding process and how welding machines and accessories are set up and used. You will also find information on selecting an electrode. The personal safety equipment and precautions are also described.

How Process Works

A typical SMAW outfit consists of an electric welding machine, two welding cables, a ground clamp, an electrode holder, and a covered metal electrode. Electric current from welding machine is used to form an electric arc between tip of electrode and work.

Welding is started by touching end of electrode to base metal, then lifting electrode about ¼ inch. This forms arc, which produces temperatures up to 5550°C. The intense heat at arc area instantly melts base metal and begins to burn covering off electrode and melt core.

The melted core becomes filler metal for weld and decomposition of flux forms a protective gaseous atmosphere around arc area. The gas forms a shield against contamination from oxygen and nitrogen in surrounding air. Additional shielding is provided by electrode flux, which forms a deposit called slag.

The shielding gas is ionized, and conducts electricity and maintains stability of arc.

Welding Voltage and Current

Either direct current (DC) or alternating current (AC) is used. The arc voltage or working voltage is voltage present in welding circuit while an arc is struck and welding is being done. The arc voltage ranges from 15V to 40V depending on arc length.

The open circuit voltage is voltage generated by welding machine when no welding is being done. Open-circuit voltages are normally set between 50V and 100V, but drops to arc voltage level when an arc is struck and welding begin.

Arc Length

In any electrical circuit, there is a correlation between voltage, current and resistance. The best results are normally obtained with an arc length about diameter of electrode. 

When arc length is increased, less current flow occurs because of increased resistance. The result is a cooler arc and a greater tendency to spatter. There will be less penetration of weld, increased exposure to oxidation and contamination, and an erratic, unstable arc.

When arc length is reduced, less resistance more current flows with less voltage and arc becomes hotter. With thin material, heat can melt a hole in welding, porosity, and undercutting of adjacent base metal. 

Polarity

For DC machines, this is important. When electrode is negative and work piece is positive, this is called Straight Polarity. The opposite of this is Reverse Polarity.

DCSP or direct current straight polarity is characterized by faster melting of electrode, weld puddle being broad and penetration into base metal is relatively shallow. This is used when fast welding speeds and high deposition rates are required.

DCRP or direct current reversed polarity results in a hotter arc, making deeper, narrower weld puddle. This is used for structural welding, multi pass welds, and applications requiring deep penetrations.

Most electrodes are designed to be used with only one polarity.

Power Sources

Your Soap Base Melt and pour soap base is premade. This means that you can buy a small amount, cut off a piece, and use it to wash your hands. However, most of us see this as just first step into creating wonderful looking bars, slabs, domes, rounds, squares or rectangles of colorful and/or beautifully scented soap.

This can only be done if your soap base is well made. How can you find out? First of all, stay away from soap base with a very long list of ingredients. Don’t purchase soap base that doesn’t have any ingredients listed. The manufacturer is required by law to list what’s in that soap base. If you’re shopping online, make certain that ingredient list is posted on web site. If not, go to another site.

As with food, ingredients listing on soap bases begin with most prominent component listed first. For melt & pour glycerin soap base you’ll want to see word GLYCERIN within first two or three ingredients. If not, you might just not have a great product, or you may have a coconut soap base. There’s nothing wrong with coconut soap, it’s just a bit heavier than glycerin soap, and it’s not translucent.

Soapy Myths The most common myth is that glycerin soap doesn’t contain lye. Yes it does. ALL soap contains lye. Lye is mixed with fats and water and in case of melt & pour, other clarifying ingredients such as sugar, alcohol, propylene glycol and sorbitol. The soapy fact here is that once you purchase glycerin soap base YOU don’t have to use any lye. And that’s what’s so appealing to us.

Not 100% Glycerin Soap Time and again I’ve read of people who claim they use 100% Glycerin soap. That’s impossible as it would be a jar of a clear, sticky plant-derived substance that’s devoid of lather and cleansing ability. What melt & pour soap contains is 100% plant glycerin – and usually at around a 20% rate. Some soap bases contain more, others less. But even at about 20% that is what helps this soap achieve its clarity and its softness – as well as its shorter lifespan in tub, sink or shower.

F.O. Versus E.O. First off, learn what do these initials mean. F.O. = Fragrance Oil. E.O. = Essential Oil. Now, what’s difference?