What You Should Know about SMAW!

Written by Thomas Yoon

In shielded metal-arc welding,repparttar intense heat from an electric arc is used to melt and fuse metals to form a weld. It is one of repparttar 116110 oldest and most widely used welding processes. Although used chiefly for joining iron and mild steels, shielded metal-arc welding is well suited to maintenance tasks becauserepparttar 116111 equipment is relatively inexpensive, simple to operate, and can be used for welding many different kinds of metals.

Below, you will find explanations describingrepparttar 116112 shielded metal-arc welding process and howrepparttar 116113 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.

Howrepparttar 116114 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 fromrepparttar 116115 welding machine is used to form an electric arc betweenrepparttar 116116 tip ofrepparttar 116117 electrode andrepparttar 116118 work.

Welding is started by touchingrepparttar 116119 end ofrepparttar 116120 electrode torepparttar 116121 base metal, then liftingrepparttar 116122 electrode about ľ inch. This forms repparttar 116123 arc, which produces temperatures up to 5550įC. The intense heat atrepparttar 116124 arc area instantly meltsrepparttar 116125 base metal and begins to burnrepparttar 116126 covering offrepparttar 116127 electrode and meltrepparttar 116128 core.

The melted core becomes filler metal forrepparttar 116129 weld andrepparttar 116130 decomposition ofrepparttar 116131 flux forms a protective gaseous atmosphere aroundrepparttar 116132 arc area. The gas forms a shield against contamination from oxygen and nitrogen inrepparttar 116133 surrounding air. Additional shielding is provided byrepparttar 116134 electrode flux, which forms a deposit called slag.

The shielding gas is ionized, and conducts electricity and maintainsrepparttar 116135 stability ofrepparttar 116136 arc.

Welding Voltage and Current

Either direct current (DC) or alternating current (AC) is used. The arc voltage or working voltage isrepparttar 116137 voltage present inrepparttar 116138 welding circuit while an arc is struck and welding is being done. The arc voltage ranges from 15V to 40V depending onrepparttar 116139 arc length.

The open circuit voltage isrepparttar 116140 voltage generated byrepparttar 116141 welding machine when no welding is being done. Open-circuit voltages are normally set between 50V and 100V, but drops torepparttar 116142 arc voltage level when an arc is struck and welding begin.

Arc Length

In any electrical circuit, there is a correlation betweenrepparttar 116143 voltage, current andrepparttar 116144 resistance. The best results are normally obtained with an arc length aboutrepparttar 116145 diameter ofrepparttar 116146 electrode.†

Whenrepparttar 116147 arc length is increased, less current flow occurs because ofrepparttar 116148 increased resistance. The result is a cooler arc and a greater tendency to spatter. There will be less penetration ofrepparttar 116149 weld, increased exposure to oxidation and contamination, and an erratic, unstable arc.

Whenrepparttar 116150 arc length is reduced, less resistance more current flows with less voltage andrepparttar 116151 arc becomes hotter. With thin material,repparttar 116152 heat can melt a hole inrepparttar 116153 welding, porosity, and undercutting ofrepparttar 116154 adjacent base metal.†


For DC machines, this is important. Whenrepparttar 116155 electrode is negative andrepparttar 116156 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 ofrepparttar 116157 electrode,repparttar 116158 weld puddle being broad and penetration intorepparttar 116159 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

Most AC power sources contain a transformer that steps down line voltage torepparttar 116160 level required for welding (normally less than 100V)

Melt & Pour Glycerin Soapcrafting: What You Need to Know

Written by Lisa Maliga

Crafting melt & pour glycerin soap looks effortless and isrepparttar perfect gift to give any time ofrepparttar 116109 year. Better yet, why not just start making and selling it? Apparently, some over-enthusiastic people think that because glycerin soap is so easy to craft; it can be sold with little to no preliminary testing. After youíve made your first batch you might be just beginning your way to rivaling Primal Elements, yet youíre nowhere near ready to sell.

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 justrepparttar 116110 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. Donít purchase soap base that doesnít have any ingredients listed. The manufacturer is required by law to list whatís in that soap base. If youíre shopping online, make certain thatrepparttar 116111 ingredient list is posted onrepparttar 116112 web site. If not, go to another site.

As with food,repparttar 116113 ingredients listing on soap bases begin withrepparttar 116114 most prominent component listed first. For melt & pour glycerin soap base youíll want to seerepparttar 116115 word GLYCERIN withinrepparttar 116116 first two or three ingredients. If not, you might just not have a great product, or you may have a coconut soap base. Thereís nothing wrong with coconut soap, itís just a bit heavier than glycerin soap, and itís not translucent.

Soapy Myths The most common myth is that glycerin soap doesnít contain lye. Yes it does. ALL soap contains lye. Lye is mixed with fats and water and inrepparttar 116117 case of melt & pour, other clarifying ingredients such as sugar, alcohol, propylene glycol and sorbitol. The soapy fact here is that once you purchaserepparttar 116118 glycerin soap base YOU donít have to use any lye. And thatís whatís so appealing to us.

Not 100% Glycerin Soap Time and again Iíve read of people who claim they use 100% Glycerin soap. Thatís impossible as it would be a jar of a clear, sticky plant-derived substance thatís devoid of lather and cleansing ability. What melt & pour soap contains is 100% plant glycerin Ė 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 Ė as well as its shorter lifespan inrepparttar 116119 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, whatísrepparttar 116120 difference?

A fragrance oil contains up to 200 components to make it smell like a fresh-baked slice of chocolate fudge brownie, a luscious ripe raspberry, or a just-picked jasmine flower. Fragrances often contain natural ingredients, but also a lot of synthetic ones. Theyíre created in a lab, and are less costly than essential oils. They are also more plentiful. Another advantage is that you can obtain your favorite perfume or cologne for just a few dollars an ounce!

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