Oxy-acetylene welding and cutting, including information on acetylene, oxygen, electric welding; a practical and complete work on the use and maintenance of apparatus, and the weling of various metals--including special castings and parts

Front matter

Class 1,S jX?- Book- M/&-

Gopiglit>J -/-fct4

COKflRIGHT DEPOSHi including Information on Acetylene, Oxygen, Electric Welding

Preface To First Edition

Some ten years ago the author started a welding" shop, using the oxy-acetylene process. He hardly knew how to light the torch, much less its operation. In this respect he was on an equal footing with a few other venturesome individuals in this country who had embarked in the same business, regarding which practically nothing was known. It follows that there were many failures and disappointments.

The author can well testify that "there is no royal road to learning," and yet in offering this treatise he is prompted by the belief that the man who goes ahead may smooth out some of the rough spots, and thereby assist those who come after.

Preface To The Sixth Revised And Enlarged Edition

This book has met with such a very cordial reception on the part of the public that the sixth revised and enlarged edition has just been issued, more than 30,000 copies of the previous editions having been sold. To the present edition much new valuable material has been added, which will be helpful to those interested in the art of welding.

In a work of this kind it is but fair to state that the author is indebted for suggestions and ideas to many individuals and writers.

P. F. Willis.

November, 1922.

Dedication

This work is respectfully dedicated to Mr. George L. Walker, a gentleman with whom the author worked side byside in the infant days of welding, and for whom, by reason of his patience, carefulness, skill and judgment a high regard and esteem was created.

CHAPTER I Acetylene

History. Generation. Properties. Sizes and Cost of Tanks. Hazards in Connection with Acetylene. Disadvantages of Compressed and Generated Gas. . . .7-26

Chapter II

Properties. Various Methods of Manufacture with Description of Each Process such as: Sodium Peroxide, Chlorate, Brin's or Barium Oxide, Lavoisite, Electrolysis of Water, Liquid Air. Effect of Temperature on Compressed Gas. How to Determine Contents of Cylinder Under Pressure, including Table for Same. Effect of Impurities in Gas 27-42

Chapter III

Requisites for Welding Torch. Difficulties in Manufacture. Flash-backs. Waste of Oxygen. Different Types of Torches with Opinions of Authorities. Chemical Changes Taking Place in Oxy-Acetylene Flame. Objections to Some Torches. Operation of Cutting Torch. Theoretical Amount of Oxygen Necessary for Cutting. Effect on the Steel 43-64

Chapter IV

Regulators and Reducers. Construction and Care. Gages. Goggles. Acetylene Generator. Important ConsiHpvqtions. Portable Generators. Directions vi CONTENTS

for Connecting up Tank or Portable Welding Outfit. Installation of Generator Plant 65-84

Chapter V

Necessary Tools for Repair Welding. Cleaning the Metal. Beveling. Pre-Heating Methods and Devices. Artificial and Natural Gas. Kerosene and Gasoline Torches. Furnaces for Pre-Heating. Expansion and Contraction of Metals. Melting Points of Metals. Regulation of Flame. Execution of a Weld 85-103

Chapter VI

Welding of Cast Iron, Steel, Brass or Bronze, Copper, Aluminum. Malleable Iron and Lead Burning. 104-121

Chapter VII

Welding of Sheet Iron. Welding of Connections. Machine Welding of Sheet Metal. Welding of Gas, Ammonia, Air, Steam, and Water Pipes and Mains. Tests and Costs of Same. Illustrations of Welding 122-140

Chapter VIII

Fire Box Welded to a Height of Three Feet. All Welded Fire Box. All Welded Door and Flue Sheets. Welding Less than Full Door Sheets. Welding of a Simple Crack, Patch, Cracks in the Throat Sheet of Boiler, Cracks in Side Sheets, Patches in Fire Sheets. Welding of Door Collars, Door Holes, Caulking Edge. Welding Sheet to Mud-ring. Welding Locomotive Flues 141-177

CHAPTER IX Welding of Various Pieces

Welding of Automobile Cylinder, Lug on Manifold. Repairing Scored Cylinder. Welding Arm of Alumi-

CONTENTS vii

num Crank Case, Crack in Aluminum Oil Pan, Fly- Wheel, Large Cylinders, Crank Shaft, Automobile Frames. Tempering. Finishing a Weld While Hot with a File. Clamps for Holding Sheet Metal Edges in Alignment. Welding Horse. Welding Dies, High Carbon Tool Steel to Low Carbon, Manganese Steel. Aluminum Soldering. Use of Oxygen for Removing Carbon. Cost Card. Receipt Ticket. Description of Welded Castings 178-217

Chapter XI

Spot, Butt and Arc Welding. Direct and Alternating Current Machines. Kinds of Electrodes. Specifications for Electrode Wire. Protection for The Operator. Information Required of Prospective User. Length of Arc. Preparation of Metal for Welding. Expansion and Contraction. Instructions for Beginners. Tables and Useful Information 226-248

FIRST EDITION Published November, 1916.

SECOND EDITION Published December, 1917

THIRD EDITION Published November, 1918

FOURTH EDITION Published December, 1919

FIFTH EDITION Published September, 1920

SIXTH EDITION Published November, 1922

Chapter I Acetylene

History — Generation — Properties — Sizes and Cost of Tanks — Hazards in Connection with Acetylene — Disadvantages of Compressed and Generated Gas.

What is Acetylene?

A hydro carbon gas composed of equal volumes of carbon and hydrogen. By weight it is composed of 93% carbon and 7% hydrogen.

When was it discovered?

In 1836 by Davy, an English chemist, and Berzelius, a Swiss chemist.

From ivhat is Acetylene obtained?

From calcium carbide.

What is Calcium Carbide?

It is a substance, hard like rock, of a grayish color, and possessing a slight crystalline structure.

When ivas it discovered?

In 1892 by an American chemist, named Willson, at Spray, N. C.

How is it manufactured?

Lime and coke in the proportion of 56 parts by weight of the former to 36 parts of the latter are fused or melted together in an electric furnace. It is cooled and crushed and is then assorted as to size by means of screens.

How is Acetylene obtained from Calcium Carbide? .

When calcium carbide and water are

brought together, acetylene is formed.

This is accomplished as follows :

The calcium in the calcium carbide combines with some of the oxygen in the water and forms first calcium oxide or quick lime, and then calcium hydroxide (slacked lime). The carbon in the calcium carbide combines wth some hydrogen from the water to form acetylene, the chemical symbol of which is C 2 H 2 .

Is there more than one method of bringing the Carbide and water together?

Yes, there are three methods.

Name them.

First, water to carbide; second, recession ; third, carbide to water.

Explain each method.

The " water to carbide" method consists in allowing water, drop by drop, to fall upon a body of carbide. This was the earliest method of generating acetylene and its adoption was due to the fact that it was easier to control the flow of water than it was the feeding of the carbide; especially as the carbide first put on the market was not uniform as to size.

The "recession" method consists in allowing water to rise, coming in contact with either a mass of carbide or successive layers of carbide.

The "carbide to water" method consists in feeding the carbide in small amounts into a large volume of water.

Which is the best?

The ' i carbide to water. ' '

Why?

After generation is impossible and purer gas is produced. Again when carbide and water are brought together heat is evolved.

Now this heat can be considerable, sometimes reaching 1000° F., or it can be negligible, depending entirely upon the amount of water. If there is a sufficient amount of water both the carbide and the water will be kept cool. It has been found that if for each pound of carbide, one gallon of water is supplied, the temperature is kept down — in fact, cannot possibly exceed 212° F., and in practice never goes that high. The "carbide to water" method is the only one that guarantees a sufficient amount of water to assure cool generation.

What effect does heat have on Acetylene during generation?

If the heat should rise high enough, what chemists term polymerization takes place. By this is meant that the acetylene undergoes a change and is transformed into other gases, such as benzol, styrolene, etc. These latter gases require for their combustion a different amount of oxygen than does acetylene, and their flame temperature is not so high.

A temperature that would produce polymerization, would also be hazardous, and if there was any mixture of air with the gas, an explosion would likely result.

Is it possible to explode Acetylene?

Yes.

How?

First, when mixed with air in the proper proportions — 3% to 58% of acetylene to the rest air — and in the presence of a spark or flame.

Second, at a pressure of 24 pounds it is possible for it to explode without any air mixture, in the presence of spark or flame.

Third, when compressed in an ordinary container to 30 pounds or more it may explode without any air mixture and without a spark or flame. Neither concussion or shock are necessary to produce the explosion. An explosion of this character is generally attributed to decomposition, although some claim that it is due to impurities in the carbide, such as sulphur and phosphorus forming combinations which ignite spontaneously.

Is it possible to compress Acetylene to 25 pounds or higher safely?

Yes.

How?

The container is first filled with a porous substance, such as asbestos cement. It is then further filled with an inflammable liquid called acetone. This liquid, acetone, has been found to possess the peculiar quality of dissolving or absorbing 25 times its volume of acetylene at atmospheric pressure and continues to do this for each atmosphere of pressure (15 pounds) it is put under.

While the asbestos cement apparently fills the tank, in reality, on account of its porosity, only 20% of the space in the tank is occupied by the asbestos ; acetone to the amount of about 43% of the capacity of the tank is then added. This leaves about 37% of the contents of the tank for acetylene as it is taken up or dissolved by the acetone. This absorbing or dissolving quality of the acetone is so remarkable that it may be well to compare the amount of acetylene that a tank of one cubic foot capacity would contain under fifteen at-

Fiff. 1 Commercial Acetylene Co.'s Tank

mospheres (225 pounds) and the amount the same size tank will contain under the same pressure but with the gas dissolved. In the first instance there will be approximately fifteen cubic feet of gas. We simply multiply the cubic contents (one foot) by the number of atmospheres (fifteen).

In the latter, however, there will be about 161 cubic feet, or roughly estimated at about ten times as much gas as in the first tank. This is obtained as follows :

The amount of acetone is about 43% of the contents of the tank whose capacity was assumed to be one cubic foot. Therefore, the acetone occupies .43 of a cubic foot. At atmospheric pressure the acetone dissolves twenty-five times its volume of acetylene, so that in this case at zero gauge pressure there is in the tank .43x25 or 10.75 cubic feet of acetylene and at 225 pounds pressure there will be 10.75x15 or 161 cubic feet.

Does Acetylene exercise a toxic action if air containing a large proportion of it is breathed?

The best authorities agree that acetylene itself possesses very small poisonous qualities, so that the danger of breathing it is practically nil. This is because it is almost free of carbon monoxide.

How much Acetylene will a pound of carbide produce when made with a generator?

Conservatively 4% cubic feet for the lump size and 4% cubic feet for the very small size. One carbide manufacturer claims five cubic feet and another 4.8 cubic feet, but iheir figures cannot be obtained.

What is the present price of carbide?

Five and three-quarter cents without a contract; from 5 to 4.8 cents per pound with a contract, according to consumption.

What is the cost of Acetylene per cubic foot made from, a generator at above prices for carbide?

Not to exceed l 1 ^ cents per cubic foot or

$1.25 per 100 cubic feet.

What is the price of dissolved or compressed Acetylene?

From $2.45 per 100 cubic feet to large users to $3.00 per 100 cubic feet to the average consumer plus freight on the full tank and on the empty tank returned.

Taking into consideration the freight, what is the average cost of "tanked"

Acetylene?

Four cents per cubic foot.

What size or capacity of Acetylene tank

shoidd be used for welding? '

Jnder no circumstances should a tank

of less capacity than 100 cubic feet be used.

A tank should not be discharged at a faster rate than one-seventh of its capacity per hour. This means that a welding tip should not be used on a 100-cubic foot tank if it consumes more than 15 cubic feet per hour. The use of small automobile tanks should be discouraged, only the very lightest work can be done and the cost of the gas is considerably more than it is when using the regular welding cylinder.

When would you advise the use of "tanked" Acetylene?

When only occasional welding or cutting is done or where portability is desired.

When ivould you advise the use of a generator?

When stationary welding or cutting is done, using about 200 cubic feet of acetylene or more per week.

What is the saving over tanked Acetylene per 100 cubic feet?

The difference between $1.25 for generator gas and $4.00 for tanked gas, or $2.75.

Has the tanked gas any disadvantages? Yes.

Name them.

(1) Inconvenience and delay in shipping tanks.

(2) No assurance that you receive full amount of gas in tank.

(3) Some gas always remains in the tank.

(4) The solvent (acetone) mixes with the acetylene and produces a bad weld.

(5) Certain make of tank not your property.

(6) Likelihood of leakage from tank greater than from generator on account of higher pressure.

(7) Lack of sufficient gas to finish a job.

(8) Hazard.

Explain each of the above.

INCONVENIENCE AND DELAY IN SHIPPING TANKS

The inconvenience and delay incident to shipping tanked acetylene is a serious problem. Delays in shipment will necessarily occur, and they usually occur when the welding plant is most needed. But, with the very best possible time, it is usually two or three days before a full tank is received. One of the important values of a welding plant is readiness to serve. Anyone familiar wth custom welding realizes that 75% of the repair work must be gotten out in a hurry. It is rush work, and your value to the customer increases when you are in a position to at all times take care of the work promptly.

NO ASSURANCE THAT YOU RECEIVE FULL AMOUNT OF GAS IN TANK

With tanked acetylene you must depend upon the correctness of the companies recharging the cylinders. A gauge on the tank will only indicate the pressure of the gas — not the quantity of gas. No one but the recharging people can tell how much gas is in a cylinder as the amount of gas depends not only upon the size of tank and the pressure, but also upon the quantity and quality of the solvent — acetone — in the tank. It takes a smart man that can look through a steel tank and tell haw much acetone is on the inside, and there is no way for the customer to measure it. No one questions the honesty of any of the firms engaged in the filling of acetylene tanks, but their employees are human ; they are likely to make mistakes; and as a matter of fact they do sometimes make mistakes.

SOME GAS ALWAYS REMAINS IN THE TANK

•

With tanked gas you never get all the gas out of the tank. A quite considerable amount of gas remains and is shipped back to the recharging station to be resold to you in vour next tank.

THE SOLVENT ( ACETONE ) MIXES WITH THE

ACETYLENE AND PRODUCES

A BAD WELD

When tanked acetylene is used, the gas from a full tank will produce an excellent weld, but as the pressure and the amount of gas in the tank is lowered, the acetone or solvent comes off also, adulterating the acetylene, contaminating it with a hydro-carbon of less heat units and consequently lowering the temperature of the name. This acetone also contains impurities which affect the strength of the weld. That the acetone is carried off and burned with the acetylene is evidenced by the fact that one of the refilling companies at one time made a charge of 2c per ounce for whatever loss of acetone was shown when the tank was returned.

A CERTAIN MAKE OF TANK NOT YOUR PROPERTY

Acetylene tanks are simply loaned by one of the different concerns compressing acetylene* under a "Service Agreement," for which they charge, and you are compelled by the agreement to get your recharges from them. You do not own the tank. It is not even leased to you. You simply pay a certain amount for the privilege of buying their gas and you cannot go into the open market and buy your acetylene.

LIKELIHOOD OF LEAKAGE FROM TANK GREATER

THAN FROM GENERATOR ON ACCOUNT

OF HIGH PRESSURE

The pressure of the gas in the high pressure generator cannot exceed 15 pounds. The pressure of the gas in an acetylene tank is at least 225 pounds, and maybe more. It must be obvious that the likelihood of leakage is greater under the higher pressure.

LACK OF SUFFICIENT GAS TO FINISH A JOB

It often occurs that a welding job comes in which will take a fair amount of gas. Perhaps a part of the gas in your tank has been used on other work and not enough remains to do this particular job. What are you going to do? You can use what gas is in the tank to partially weld the casting, then send your empty tank in and write or wire for another full one. This means th^t the casting cools down and you have lost your heat, which is expensive ; besides, distortion often occurs on account of this cooling when only partially welded. You could send the partially full tank back at once and order a full tank, but this means loss of gas in the tank returned.

HAZAKD

Any power-producing agency has inherent hazards, and acetylene is no exception. A generator of good design and workmanship possesses no greater hazards than a compressed or dissolved acetylene tank. Some tanks have exploded; so have some generators ; so that any claims to the contrary, it is a stand-off between the two on the question of hazard.

What are the disadvantages of a generator?

First, there is a slight variance in pressure of the gas between locking and releasing the motor. This necessitates occasional adjustment of the flame by means of the torch cocks. This is largely overcome by means of a special regulator.

Second, recharging the generator and removal of sludge requires about twenty minutes. The indolent may offer this as an objection.

Third, cost of generator is much more than cost of a tank.

Fourth, some precautions must be taken to prevent freezing in winter.

Fifth, generators should not be moved when rilled with carbide, and used for portable work.

Sixth, generator house should be provided, which necessitates an expense.

What fuel gas is best adapted for welding?

Acetylene.

Why?

The temperature of an acetylene flame when burned with oxygen is in excess of 6300° F. This is a temperature exceeding by over 2000° F. its nearest rival, hydrogen. It is the flame temperature that counts in welding and not the B. T. XL's of a gas.

What are some of the gases that have at various tunes tried to compete with Acetylene?

Hydrogen, Blau gas, Wolf gas, Thermolene, Oxy-carbo, etc.

What are the objections to the above?

First, it is impossible to do heavy welding unless these gases are enriched with acetylene.

Second, usually, the cost of doing such work as is practical, is more than it would cost using acetylene when all factors, such as labor, are considered.

Why does Acetylene, when burned with oxygen, give us the hottest fuel flame known?

Broadly speaking, the gas which has the greatest amount of carbon and the least amount of hydrogen will give us the hottest flame. Acetylene contains by weight 93% carbon, almost approaching gaseous carbon. There is another property which acetylene possesses, which assists in increasing the flame temperature, and it is the fact that it is an endothermic compound.

What is meant by an Endothermic Compound?

It is a compound whose formation from elementary substances is attended with -absorption of heat. The electric furnace has made the manufacture of carbide practicable. Authorities differ as to whether calcium carbide, when formed, absorbs or liberates heat, but they are agreed that when carbide and water are brought together slacked lime and acetylene are formed and that the former liberates heat, while the acetylene absorbs heat. When the acetylene is burned, this absorbed or stored-up heat is liberated, and helps to increase the flame temperature.

What is it that limits the temperature of the Oxy-Acetylene flame?

The dissociation point of carbon monoxide— (CO.).

What is meant by the dissociation point of an inflammable gas?

It is the temperature at which the gas refuses to unite with oxygen.

At what pressure does Acetylene liquefy?

At 26 Atmospheres (282 lbs.)— At 32 Degrees F. At 40 Atmospheres (588 lbs.) — At 70 Degrees F.

What is Copper Acetylide?

It is a compound which is formed when acetylene is exposed for a considerable time to copper.

What properties, if any, does this compound possess?

It is explosive.

What lesson do we learn from this?

That under no condition should copper be used when it will come in contact with acetylene.

What is the density or specific gravity of Acetylene?

Assuming air to be unity or 1, it is .91 for acetylene. It is therefore slightly lighter than air.

Does Acetylene, ivhen burned, give off any Ultra Violet Rays?

It does not, so that no harm can come to the eyes from this score. However, it must be remembered that any bright light will in time tire and weaken the eyes so that it is strongly recommended that smoked glasses be worn.

What is the weight of a cubic foot of Acetylene?

.069 of a pound.

How many cubic feet of Acetylene does it take to weigh a pound? 14.5 cubic feet.

What is the ignition temperature of a mixture of Acetylene and air?

About 805 °F.

What concerns manufacture Carbide?

American Carbolite Company.

Canadian Carbide Company.

Union Carbide Company.

Gas Tank Products Company.

What companies furnish compressed Acetylene?

Commercial Acetylene Weldiiig Company.

Prest-O-Lite Company.

Searchlight Company.

What is the policy of each company with reference to furnishing the gas?

The Commercial Acetylene Company seldom sell any of their tanks. They usually loan them to responsible people without charge. They furnish tanks having a capacity of 125 cubic feet, 250 cubic feet and 500 cubic feet.

The Prest-O-Lite Company manufactures two sizes of tanks, one of which contains practically 100 cubic feet of gas and the other 300 cubic feet. They charge under a service agreement $37.50 for the small size, and $75.00 for the large size tank.

The Searchlight people charge $37.50 for the small tank, and $75.00 for the large tank.

Each of these companies will refill only their own tanks.

Which compressed Acetylene companies offer the best propostion to the user?

All three companies now loan their tanks if a contract is obtained in which the consumer agrees to purchase the gas for one year, return the tank in good condition, and to pay a rental charge of usually 25 cents per week if the tank is kept longer than 90 days. About 20% more is charged for the gas in * 'loaned' ' tanks than is charged where the tanks are owned by the user. The prices charged for the gas is practically the same by each company, so that the only thing to consider in most cases is service and freight charges.

Are there any hazards in connection with Acetylene?

There are some who believe in minimizing the hazards in connection with acetylene. The writer does not belong to that school. Any sensible man realizes that any power-producing agency, whether it be steam, electricity, gasoline or acetylene holds within itself possibilities for good or evil. It would seem that one way of avoiding accidents with acetylene is to apprise and thoroughly familiarize one's self with its properties. "When properly handled, acetylene will unite in a molten mass, a 6x6 inch iron beam, and the same power which accomplishes this wonder of yesterday will play havoc if one becomes careless and .refuses to follow a very few simple and common sense rules. Millions upon millions of feet of acetylene, both tanked and generated, are used yearly with but a trifling number of accidents as compared with the installations.

A few acetylene tanks and generators have exploded. Where the explosion occurred inside the generator, it was seldom of a serious character. Where considerable damage results it is usually caused by the gas leaking out in considerable quantities in the room from the tank or the generator and mixing with the air. Never under any circumstances try to find a leak with a lighted match. Elsewhere we will advise more fully as to the care that should be observed when working with acetylene.