The Iron Age 1934-10-04: Vol 134 Iss 14

YEAR SERVICE THE METAL WORKING INDUSTRY TAILORED FIT YOUR NEEDS Counter File 4 Specially Designed Berloy Air-Conditioning Cabinet YOUR problem involves the creation, manufacturing redesigning product built sheet steel, consult Berger. Here, one organization, over period half-century, have been assembled large group specialists and the most complete facilities for rapid and economical production sheet metal air conditioning cabinets, colorful boiler jackets, sanitary kitchen cabinets and hundreds other items have been designed and built Berger for clients whose names are nationally known...Even your only requirement expert advice, you will find interview with Berloy engineer adventure constructive thinking. THE BERGER MANUFACTURING CO., CANTON, OHIO Division REPUBLIC STEEL CORPORATION Table oneivin MANAGEMENT OCTOBER 1934 PROCESSES -:- NEWS THE IRON AGE...... OCTOBER 1934 Money spent for repairs plants must come out profits. Continual repairs are steady drain the funds that should stockholders. why all repairs in- volving the use sheet metal should studied, that the loss caused rusting may kept minimum. STOCKHOLDERS USE why Toncan Iron should viewed the light its ultimate cost—not merely the material first cost. Toncan Iron the most economical ferrous metal for industrial uses—ducts —roofing and siding buildings— gutters and downspouts—wherever rust corrosion cause rapid failure metals only slightly lower cost. true alloy refined iron, copper and molybdenum. resists rust better than any metal its price class, and surpassed only the stainless steels. ductile and easy work. lasts years longer, and consequently costs less—allows more for profits. More than ton Toncan Iron was used for the gutters and downspouts the Van Camp Oil Products Co. Ky. Permanence.” copy will sent request. GENERAL OFFICES YOUNGSTOWN, OHIO ALLOY AND CARBON STEELS TONCAN STAINLESS STEEL AND TUBULAR PRODUCTS BARS AND SHAPES AND COLD ROLLED STRIP PLATES BLACK, BLUE ANNEALED AND GALVANIZED SHEETS SPECIAL FINISH TIN PLATE NUTS, BOLTS, RIVETS, ETC. WIRE PRODUCTS DIE ROLLED PRODUCTS THE IRON AGE, published every Thursday the AGE CO. Publication Office: Cor. Chestnut 56th Sts., Philadelphia, Pa. Executive Offices: 239 39th St., New York, Y., Entered second class matter the Post Office Philadelphia under Act March 1879. $6.00 year Canada $8.50, $12. 00. Vol. 134. No. 14. Many uses for Toncan Iron are suggested Path ‘ | | | | | > | : a der Act THE IRON AGE October 4,1934 J. H. VAN DEVENTER G. L. LACHER W. W. MACON T. H. GERKEN R. E. MILLER Editor Managing Editor Consulting Editor News Editor Machinery Editor Pittsburgh Detroit Boston Cleveland Chicago Bditor Emeritus Washington Contents CODE 1934 Fed Up— Registration No. A-3:31 -01590 Avoiding Production Difficulties And Now the Light-Weight Street Car Production Problems Enameling Proposed Republic Steel Reorganization New Equipment Automotive Industry September Pig Iron Construction and Equipment Buying Index Advertisers 114 THE IRON AGE PUBLISHING COMPANY FRANK, President GRIFFITHS, Secretary BAUR, General Advertising Manager PUBLICATION OFFICE: Corner Chestnut and 56th Sts., Philadelphia, Pa. EXECUTIVE OFFICES: 239 West 39th St., New York, Y., ADVERTISING STAFF Member, Audit Bureau of Circulations Emerson Findley, 311 Union Bldg., Cleveland Member, Associated Business Papers B. L. Herman, 675 Delaware Ave., Buffalo, N. Y. H. K. Hottenstein, 802 Otis Bidg., Chicago Published every Thursday. Subscription Price: Peirce Lewis, 7310 Woodward Ave, Detroit United States and Possessions, Mexico, Cuba, Charles Lundberg, Chilton Bldg., Chestnut & $6.00; Canada, $8.50, including duty; Foreign 56th Philadelphia, Pa. $12.00 year. Single Copy Cents Ober, 239 39th St., New York W. B. Robinson, 428 Park Bidg., Pittsburgh Cable Address, ‘‘Ironage, Sweetser, 239 West 39th St., New York D. C. Warren, P. O. Box 81, Hartford, Conn. EIGHTIETH YEAR SERVICE THE METAL WORKING INDUSTRY at’s ate ical ver htly and its and full range special alloys, tool steels, stainless and heat resisting steels are immediately available through the Ryerson Steel-Service Plants. clude all the major specifications. Ten plants, strategically located, provide for immediate distribution throughout the principal industrial areas. All other steel and allied products are also carried for immediate shipment. Experienced organization and unequalled equipment assure dependability, ac- curacy and speed. Whether you need few pounds carload, your order will have our personal attention and will shipped once. Write for the Ryerson Stock Immediate Steel. JOSEPH RYERSON SON, INC., Chicago, Milwaukee, Cincinnati, Detroit, Cleveland, Buffalo, Boston, Philadelphia, Jersey City THE IRON AGE..... OCTOBER 1934 mon flati stall t the ton poun main othe City THE IRON AGE ... OCTOBER 1934 ESTABLISHED 1855 Vol. 134, No. Fed Up— people, matter how buoyant and ener- getic, can continue stand under unre- lieved tension. Reaction must come and, the case this country, has come. The feverish activity that has accompanied the creation the New Deal has been wearing. The failure planned economy work out according plan has been dis- appointing. Emotionally, America wants and needs rest. And yet the popular mood still relatively free from partisan bias. means everything that has been done the name the New Deal charged the debit side the ledger. The initial monetary moves the present Administration are generally credited with halting the cumulative de- flationary forces which had prostrated the banks, stalled industry and plunged the country into the depths despair. Subsequent action this sphere, although times disturbing confidence, has failed warrant the fears alarmists. And even today, the monetary policy, lack policy, Washing- ton probably not unorthodox critics repre- sent be. Final stabilization the dollar out the question long the course the British pound and other unanchored foreign currencies re- mains uncertain. While would futile deny that there are justifiable fears regarding our monetary program, especially relation the eventual possibility swollen debts driving into currency inflation, most the present dissatisfaction with the New Deal due the unhappy results Governmental efforts the field economic control industry and agriculture. Agricultural control failed take 13 the elements into account. Industrial control failed take human nature into account. The theoretical concept adequate prices necessary foundation for adequate wages led maze administrative complexities, encouraged waves speculative buying, and unleashed bitter industrial strife. Governmental sponsorship col- lective bargaining, instead making for industrial peace, set motion nation-wide campaign for unionization. gain their ends, the national unions have resorted virtually all known forms per- suasion and intimidation. Like Chinese bandits, their flying squadrons have swooped down objec- tive after objective, leaving property damage and broken heads their wake. While terrorism this type has accomplished its purpose closing plants and keeping frightened men away from their jobs, has been abhorrent all who cherish civic peace and order. Law-abiding citizens are getting impatient with private warfare that prevents industry from func- tioning normally and robs willing employees the right work. They are beginning doubt the efficacy the countless intricate bureaucratic con- trols which business has become enmeshed. They are commencing question the wisdom class- room theorists attempting uproot long-estab- lished customs and practices and implant Utopian schemes. They have grown tired experimen- tation that stifles confidence and inhibits enter- prise. They are weary alike high-flown exhorta- tion and intemperate business baiting. They are fed up. LACHER, Managing Editor, The Age. it. Special Handling ZIEBARTH Secretary and General Superintendent, Bell Howell Co., Chicago PECIAL methods checking, list- ing and caring for tools and gages become imperative when accuracy finished products makes necessary the manufacture and marking tools STANDARD PROCESS RECORD for specific jobs. For example, hole may marked 0.1255 in., 0.0003 in. ream. For operation this kind out the question use stand- ard commercial reamer. oversized tool must stoned exact require- ments and then that tool must kept, until worn out, for that one operation. The Bell Howell Co., Chicago, works entirely within the precision field. plus minus tolerance 0.0003 in. common practice the OESTON Ne.| PART Ne the are Mill ste holes All tools and gages for specific machine operation are given serial number the planning department. These numbers, well design, part and operation numbers, are specified this standard process record. 14—The Iron Age, October 1934 a recision manufacture motion picture equip- ment, which must not only operate the satisfaction the buyers sin- gle but parts must changeable for quick and accurate re- placement servicing stations, some which are half way around the globe from the manufacturing plant. Degree accuracy demanded throws all tools into two general clas- sifications; namely, general purpose tools, and special precision tools. The former can handled customary many shops, but precision tools, al- ways kept for specific jobs, require special method avoid confusion, delays production, error, and maintain accuracy. This may em- phasized pointing out that from commercial reamers measuring 0.125, 0.126 and 0.127 in. there are made and stocked reamers ranging size from 0.123 0.127 in. Now then the method handling these special tools. the first place design each complete piece motion picture apparatus =... > 4 op eac Avoids Production Difficulties given design number and each part that goes into that apparatus given part number. the tool planning department the sequence operations determined and the number and kinds gages are specified. The operations are serially numbered and all tools and gages necessary for machine operation are given num- ber which designated tool serial number. This number refers the group tools and gages that are necessary for given operation. Thus further identify the tools under each serial number certain suffixes are All gages are marked with “N.” All cutting tools that wear use are marked with “X” and fix- tures are marked “F.” there are more than one any the above they are given serial number fol- given set tools and gages used specific job the numerals are never repeated although the letter suffix not the same. For example, under tool serial number 4682 there could not X1, and N1. These would num- bered serially, as, and old number once discarded never used again; thus the tool changed the new tool would marked X4, the already being attached the There also the problem keep- ing tools and gages together. has been solved the use wooden blocks that measure about in. in. in. Each block recessed hold the tools and gages for ABOVE blocks with eri number the front hold all the and gages for dl a given operatior LEFT storage and ready for use. This crib ad- acent both pro tion and parts dena men tc the manufacture motion picture equipment plus minus tolerance 0.0003 in. common. the Bell Howell plant large number precision tools and gages are always kept for specific jobs, and avoid con- fusion and production delays and assure maintaining the close limits demanded special method handling such tools has been devised, outlined here Mr. Ziebarth specific job, and these tools and the block move together from the tool crib the production department and back the tool crib. order follow through the markings let assume that have motion picture machine designated design and that one its parts designated part number 4402. The necessary tools and gages for operation No. which drill and ream, have been given serial No. 4682. The necessary equipment consists reaming fixture two special reamers and X3; standard com- The Age, October 1934—15 ee. oes. DESCRIPTION OF WORK RAW MATERIAL Parts and tools are routed the clearing department clerk this form goes the crib attendant who places the block truck with the parts forwarded the production department mercial reamer which carries only general stock number; and five depth and plug gages—numbers N7, N8, N9, N10 and straight-edge numbered N12. All these fit recesses wooden block which has the serial number stamped it. Each tool gage that fitted this block has stamped the serial number addition the number, F1, N7, that designates the make more than one set complete tools under specific serial number then letters are added the main serial number. For example, three sets are made then their serial num- bers would 4682A, 4682B and 4682C and all tools each these three blocks would carry the extra that gage 4682A-N7 will not placed the wooden block marked 4682B and therefore supplant the cor- DESCRIPTION Pgs. No.Pgs. Block NO. ROUTING ORDER ~VELLOW—DEPT. CONTROL —BLUE—TRAVELER —PINK —TOOL CLERK SCHEDULEO TO START SCHEOULED TO FINISH TIME ALLOWECO T-uP One copy TOOL STORAGE RECORD DESCRIPTION OF TOOL rect gage 4682B-N7. This method necessary order catch errors and locate the exact tool fault when several sets like tools are use. Small special tools that wear fast and are used often are made and stock- under maximum and minimum re- quirements and drawn out needed and put into the tool block. Clearing Department Routes Parts And Orders Tool Blocks The central tool crib, fitted with steel shelving, located close the production department and adjacent the parts clearing department through which all parts process must pass they from one oper- ation another. This clearing de- partment charge clerk whose duty route parts and see that each lot parts has with the right block tools for the next oper- ation. order from the production contract department having been re- ceived the clearing department the Serial No. | Section | Shelf , USED ON The tool storage record lists all tools bearing given serial number. This new form, in., provides permanent record the use and condition all tools, furnishing pertinent data for future use. 16—The Iron Age, October 1934 clerk there issues routing order the first operation. This made triplicate form designated No. 176, two copies going the produc- tion department and one copy the tool crib. This order shows the tool serial number. The tool crib atten- dant puts the tool block with the parts and the truck moved the proper production department for the opera- tions. materials direct from raw material stores the production de- partment the tool block detivered di- rect from the tool crib. When this operation has been completed the tool block complete with all its tools, put the truck and sent back the clearing department. The tool re- j 1s tio d ST Ni | Location When tool block returned the crib, inspector checks gages that are worn beyond given limits and ordering turned the crib and another tool block, needed for the next operation, withdrawn when the parts are move the next opera- Permanent Tool Withdrawal Records Furnish Pertinent Data each tool block withdrawn from the tool crib charged the production department which destined. old practice was place card, properly marked, file. When the block was returned the card was removed and destroyed. Thus permanent record the use the the tools are greased and placed the tool was kept. new plan employs form which contains pertinent data concerning given serially numbered tool. This kept permanent rec- ord. are indicated the date each time the block was taken out, the department which was deliv- ered, the date returned the tool crib and comments the inspector. This card will show the future how often the tool has been the produc- tion department and also how often needed tool room repairs and whether has been corrected per latest change order the part. each tool block returned from all principal dimensions, rejecting the tools acements when necessary. After inspection shelf, ready for immediate use. production department must first the inspector before being stored its shelf. the inspector’s duty check all principal dimensions and see that all tolerances are observed. must make note wear, and reject tools gages that have worn beyond given limits. When the inspector has finished his work, the block has its full quota tools and after proper greas- ing the attendant, placed the shelf with the assurance that when again needed, can used very short notice and that all tools and gages will proper condition perform work the desired accuracy. Joseph Strauss, chief engineer the Golden Gate Bridge now under construc- tion cisco, design for air tram system solve the traffic prob- lems for both San Francisco’s new bridges. The trams will capable traveling 100 miles hour with safety, and the system will include Merin, Ala- meda, San Francisco and San Mateo coun- ties. Photo Key- stone View. . The Iron Age, October 1934—17 ee rep } a Structural members the car are made Cor-ten the use standardized sub-assemblies, cars can built economically different lengths widths, given different truck centers and door arrangements and made single double ended. Welding used throughout, with the exceptior the bottom part the sides ETERMINATION rail- way executives regain lost patronage resulting special attention being given new street car design, with emphasis placed com- fort passengers, reduction noise, safety, speed, operating costs and con- struction costs. determine what the The car with stanchions, hand rails and grab handle public wants and what does not get arranged for greatest convenience standing passengers. Mo- the older type equipment, sur- tor-driven fan provides ventilation, air moderately cold vey was made the Electric Railway weather being taken over the motor resistors, heat from which otherwise wasted Presidents’ Conference Committee. outcome this investigation, several experimental cars have been built and one car Brooklyn has been reconditioned and equipped with new- type noiseless trucks. special in- terest, however, car designed under the direction Hirshfeld, chief engineer the Conference Com- mittee. This car was built the Chi- cago shops the Pullman Car Mfg. Corpn. represents the result tests modern cars conventional design and study features that would suit the greatest number car lines operating this country. contemplated that the new car can put into semi-mass production, there- lowering its cost contrast with the older designs which are essentially custom-built jobs. The car designed for one man op- eration, with entrance doors front and exit doors the center. exit door can fitted the rear, de- sired. The seating capacity 47. Four 50-hp. motors are used with con- trol for single-end operation. single trolley provided. Lighting indirect avoid shadows and glare, and 10-ft. candles are available the reading plane seated passengers. Trucks are designed with rubber springs and resilient wheels and are comparatively 7 4 Iron Age, October 1934 4 ‘ q q — 7 q 3 7 m Le ls q Le Now the Light- Street Car noiseless. Structural members are made pressings Cor-ten steel, product the United States Steel Corpn. Principal dimensions are follows: Length over Length body end Length over eaves ...... 7/8 in. Length between truck Height rail top roof Height rail top floor (empty car) ..... Height floor ceiling Diameter wheels ..... ft. The weight the new car de- livered 31,400 lb. Older designs ran high 50,000 lb., but recent years this has been reduced 40,000 lb. Now the weight has been lowered about 8500 the use special steel structural members and new truck design, and, general, the employment the lightest materials and equipment consistent with low first cost and satisfactory maintenance expense. The lighter weight, course, will result operating econo- mies. The first cost street cars vital importance. High investment per car means difficulty financing and long period for amortization. With the rapid progress being made the improvement competitive equip- ment, was not believed that any solution the design problem would satisfactory did not include ROGERS FISKE Western Editor, The Age provision for greatly reduced car in- vestment. This aspect the situation has been handled providing the de- sign for the greatest degree stand- ardization consistent with legitimate variation the requirements dif- ferent companies. The method adopt- was the use standardized sub- assemblies which can assembled produce cars meeting the requirements different operating companies. this way cars can made different lengths widths, can given dif- ferent truck centers, can made single double ended and can ETERMINED patronage, the Electric Rail- way Presidents’ Conference Com- mittee has designed new street car made Cor-ten steel and built the Pullman company’s shops. The car constructed standardized sub-assemblies and can put into semi-mass pro- duction, thereby lowering manu- facturing costs. Because its light weight, the car can oper- ated speedily and economically. Welding used improve the external appearance. Trucks are special design eliminate noise and weight. New methods lighting, heating, ventilating and interior arrangement are em- ployed give passengers maxi- mum comfort. given different door arrangements while still using standardized sub- assemblies. previously mentioned, all struc- tural members the car body are made Cor-ten steel sheets. Most these are pressed shapes, though some cross members the floor frame are channels made from sheet which are spot welded two pressed angles. Side and end sills are similar construction, are the posts and carlines. Side and roof sheets are made this special steel. The floor base %-in. plywood cov- ered with 3/16-in. Masonite, which also used for the side and part the head lining. Johns-Manville insula- tion used between the floor and the window sills. The trucks are special design eliminate noise and weight. The motor frame, which various steel members are attached, part the truck structure. The side frames are tubular construction, and steel springs any kind are used. Im- proved riding qualities and great re- duction noise have resulted from the use rubber springs and resilient wheels. Journal boxes are made fabricated sheet steel and have each side cylindrical section welded the box. Vulcanized each cylindrical section rubber cylin- der through which passes bar attached the side frame. The rubber cylinder also this bar. Therefore, slip occurs be- tween either the inclosing cylinder and the bar, the bar and the rubber. The Age, October 1934—19 n l- e- p- ‘it e- n- ly All seats face forward give maximum comfort passen- gers, view the high rate acceleration and deceleratior for which the car has been designed. Seats have divided cust ions upholstered with machine-buffed leather. rect avoid shadows and glare. Ten-foot 4) able the reading plane seated passe Experience far indicates that the life these rubber springs may from five eight years, inasmuch they are not subjected oil, sunlight overload. Bolster springs follow the design just described. Wheels are the sandwich type, employing two rubber disks. steel plate, containing dowels, vulcanized each side each rubber disk, one which mounted each side the wheel web which does not touch the wheel hub. This assembly com- pressed between two steel disks, one which permanently attached the hub and the other forced into place nut moving threads the hub. Welding has been used throughout the new street car, with the exception the bottom part the sides, “skirt,” which has been riveted. has been found that this part the car most subject damage colli- sions and wears out faster than other parts. Under existing conditions riveted rather than welded the car body. One reason for the use welding improve the car’s external ap- pearance. Prof. Hirshfeld points out that the conventional street car the past has looked like series pieces pinned together. The new design, adapting the general design the motor vehicle, gives the impression unity, strength and beauty. 20—The Iron Age, October 1934 Lighting indi- ‘ Candies ngers motor-driven fan. summer, air taken from the outside. moderately cold weather air will taken over the motor resistors, heat from which otherwise wasted. When colder weath- comes, electric heating elements will turned on. These are located the discharge air ducts between the fan and the car interior. Under these conditions part the air the car will recirculated. All heating convection, there being radiant heating units. All stanchions, hand rails and grab handles are arranged for greatest con- venience for standing passengers. Seats have divided cushions and are upholstered with machine-buffed leath- er. All seats face forward yield maximum passenger comfort with the higher rates acceleration and deceleration for which the car has been designed. Experiments showed that accelera- tion miles per hr. per sec. not uncomfortable the accelera- smooth. Accordingly special controls are used. The maximum free running speed miles per hr. Service braking deceleration conforms the miles per hr. per sec., and emergency brakes decelerate miles per hr. per sec. more. The brake system the General Electric Co.’s eddy current type arranged operate conjuncton with magnetic track shoes and hydraulically-operated drum brakes. The braking feature considered important for safety and factor maintaining fast schedules. or- der hold its place fast traffic, this car must accelerate accordance with the standards set the modern auto- mobile. Likewise must have braking facilities comparable with those the automobile order enable the car give speedy service and avoid accidents. Comparatively noiseless trucks are designed with rubber springs and resilient wheels The motor frame, which various steel members are attached, part the truck structure. Side frames are tubular construction. steel springs are used Journal boxes are made fabricated sheet steel, having each side vertical cylindrical section welded the box rij ‘ q n a p es: wi Production Problems Enameling ron and Stee LeROY ALLISON and MALCOLM CATLIN the material, enamels really are glasses. They are composed cates, borates and fluorides, which melt comparatively low tempera- tures and have fairly definite physical and chemical properties. general way, these characteristics are com- parable with those found glass— both products are brittle, relatively chemical resistant, have certain tem- perature range conditions, and on. These properties, course, are devel- oped variously particular cases, de- pending largely the application the finished product. The problem manufacturing good porcelain enameled ware quite dif- ferent, naturally, from that glass- ware production. The enamel glass must made fuse rigidly and ac- curately metal, and tempera- ture sufficiently low eliminate any possibility softening the base mate- rial. this process, metal and glass are inextricably interrelated, and important that the properties both well understood. the technical sense the nature This equally true for cast iron and sheet steel, well for all types enamels. Consequently, up-to-date enameling practice has brought about rigid control over all factors relating raw materials, whether base metal the frit. Enameling plants constantly are exhibiting greater re- finement tests for the phy- sical and chemical properties the materials, with similarly improved ef- ficiency methods for proc- essing operations. Product tests, like- wise, have been developed serve not only inspection standards, but accurate guides well, for detect- ing possible sources error manu- facture. While all porcelain enamels are similar nature (silicate glasses, noted), they differ widely actual practice according the ultimate con- ditions under which they are used. The exact character service has primary bearing the selec- tion materials and enameling plant procedure. With the large and con- stantly expanding variety porcelain OUNDING out series arti- cles enameling, both rolled steel and cast iron, the authors the accompanying concluding dis- cussion touch the parts played enameling technique the base metal well the composition troubles blistering, black-speck- ing and re-boiling come for some consideration. The first two articles the series appeared June and July and were devoted the remark- able growth the enameling in- dustry both the dry and wet process fields. The next two arti- cles were published the issues Sept. and and focused par- ticularly porcelain enameled buildings, including the place the scheme things the enameled steel house. enameled iron and steel products, this can readily understood. For instance, enamels used for out- door displays and signs, well those for more recently developed ex- terior architectural purposes, must have the ability resist the action atmospheric agencies retaining their original colors for many years without deterioration; such enamels, likewise, must not chip craze through normal wear the inevitable expansion and contraction accompany- ing the changing seasons weather, for such failure cover coats would expose the underlying metal the elements. the other hand, one the most rigid restrictions applying cooking ware enamels, for example (entire freedom from harmful chemicals might absorbed foodstuffs), does not obtain all with enamels in- tended for outdoor service. Similarly, these architectural enamels, they may termed, while designed neces- sarily resist the relatively slow “working” due continual weather changes, are not required withstand the severe shocks brought about through rapid heating and cooling, the case enameled cooking ware, stove and range parts, and the like. Intimate conditions normal and abnormal service must determined fully and accurately with such enamel- iron steel products bathtubs, sinks, barber chair parts, wall panels, lamp shades and numerous other specialties. Certain enamels, such those employed for sinks, table tops, pots, pans and on, must able The Iron Age, October 1934—21 a- a- nd nis ith to- and Dip Tanks Spray Booths The enameling plant the Detroit-Michigan Stove Co. illustrates what may called the typical layout. resist the abrasion scouring pow- ders reasonable degree, well shocks through impact falling dishes other articles; again, they must withstand the action fruit acids, cleaning compounds, etc., that otherwise would result permanent surface stains. Dealing with other enameled wares, such re- quirements these may not any importance whatever for satisfactory utility. From this brief outline some the varying conditions service, evident that the enamel ware manu- facturer confronted with the funda- mental problem developing enamels most effectively suit the work and purpose for which the particular prod- uct intended. This means literally the introduction every possible variable from the composition the base metal and enamel frit the un- predictable human factors entering into any complicated fabricating process. demands constant applica- tion and attention detail from raw material finished product. The remarkable growth the en- ameling industry recent years, has brought increasing cooperation all factors concerned—producers iron and steel for this line output, manu- facturers frit individual com- position materials, and the enameler. Some the exceptional developments and accomplisments date can traced readily this joint cooperative effort. Today, the steel and iron mill constantly calling the enameling plant for technical information and re- search that will work the best in- terests all concerned, assisting develop and perfect the best base metals for porcelain enameled prod- ucts. Porcelain Enameling Two Main Classes The porcelain enameling industry may divided into two main groups, (1) plants producing enameled articles fabricated from relatively thin sheets 22—The Iron Age, October 1934 iron and steel, and (2) plants manu- facturing cast iron enameled prod- ucts. The enameling other metals, such gold and copper for jewelry and decorative purposes, older and quite significant branch the in- dustry, but hardly considered this digest mass production gen- eral porcelain enameled products. Considered briefly, the fundamental porcelain enameling plant consist forming the product, either casting pressing and punching, the case may be; cleaning the rough piece ware sand-blasting and pickling; applying the first ground coat enamel; drying and firing the product this stage; applying the next cover coat; and finally, firing the piece second time, followed in- spection, sorting, packing, shipping, Porcelain enameling differs distinct- from other types metal-finishing, such japanning and galvanizing, the firing processes. Enamels are melted the metal under intense heat, almost sufficient fuse the base material itself. While practice neces- sarily varies for different enameled products, the average firing temper- Fusibility Coefficient Expansion atures sheet steel iron ing plant range from 800 900 deg. C., for the first coat enamel, and from 750 850 deg. C., for the second enamel coat application. the other hand, the initial coat enamel cast iron fired generally 900 1000 deg. C., may required, and sec- ond cover coats such material, from 800 900 deg. The first ground coats ename! usually are applied wet liquid, either spraying, dipping slush- ing, the case may be. Cover coat application differs; enamels sheet steel generally are handled wet, while those cast iron are applied dry powder, which adheres firmly the hot ground coat, the application being made this stage the process. Again, firing practice and equipment for this purpose vary suit the char- acter product bulk output, and other controlling factors produc- tion. Bathtubs and similarly large en- ameled pieces are fired box-type furnaces, with the use enameling forks for handling the ware both and out the furnace unit, first for the ground coat firing and immediate- following, for cover coat applica- Elasticity and Compressive Strength Chemical Resistance Si0, The combinations the three different essentials the enamel batch are confined small areas indicated Opacity NaF Cof, Furnace Oryer f t] sil tion. Smaller products, such cook- ing ware and the like, are fired gener- ally continuous-type furnaces, the material being moved through the unit mechanical conveyors. The entire enameling operation re- quires but comparatively short space time. general practice the en- ameled pieces are air-cooled with reasonable speed and are then ready for cleaning and subsequent routine handling. Continuous furnace units offer certain amount retarded cooling during the firing process, but Ferro continuous enameling this can calculated readily for the final cooling the ware, which developed with desired rapidity. Number Enamel Coats least two, and frequently three coats enamel are applied both for cast iron and sheet steel products. The first ground coat provides the metal base with the actual protective coat- ing, readily understood, and were not for the demands appearance, this initial enamel application would quite sufficient for average condi- tions life and wear. The second cover coat gives the opaque white, color finish, may desired, ac- curately concealing the metal and the undercoat enamel, and allowing, well, for any necessary artistic treat- ment the finished product. matter fact, little effort has been directed the problem developing ground coat enamel that would itself provide the de- sired white colored finished surface. abate. The saving material and processing costs would considerable, large part required plant processing would eliminated automatically. Germany, particularly, there have been numerous attempts this direc- tion; some these have been fairly successful but far from the ultimate, indicating, however, possibilities the future. Technical enamelers have found simple matter perfect enamel frit and process cover metal sur- face effectively and yet adhere the urnace the plant the Florence base material properly. date, least, the experiments brought the desired attainments, and consequence, the second cover coat continues standard practice all commercial enameling operations. These two enamel coatings generally are sufficient the case darker colors. obtain good white finish, well lighter shades, third coat enamel frequently necessary. Further, decorative motifs, numerals, legends, trade-marks, etc., ex- ecuted porcelain enamel, involve ad- ditional applications and operations, but these general follow the lines the initial coatings and ordinarily present unusual problems, except- ing possibly for some special artistic embellishments individual features certain finished ware. The difficulty developing single enamel coat combining both protection and essential covering base mate- rial would indicate that the func- tions the two enamel coatings are not alike. After years practical enameling, experimentation and tech- nical discussion, the exact behavior the two enamel coats has not been definitely determined general un- derstanding and mutual agreement. Enamel chemists certainly are not accord with their views this par- ticular subject. quite evident, however, that the initial enamel coat- ing takes vital part causing the liquid enamel adhere properly the metal base under heat influence, acting the same time more Co., Kankakee, III less elastic interlayer between the metal and the succeeding cover coat. Enamel Adherence Metal Base Enamel ground coat adherence steel cast iron, other base metal, subject constantly under technical presenting basic problem that has concerned nologists for many years. rather contested topic enameling theory. Enamelers earlier days did not realize the importance the ground coat connection with adher- ence metal base, believing that the function such coating was pre- vent the carbon the iron from reducing the zinc oxide used render opaque the cover coat enamel. Later on, however, when was found possible make enamels opa- que with other, and non-reducible ma- terials, the fallacy this theory was evident. For instance, the only function the ground coat was protect the zinc oxide, intimated, The Age, October 1934—23 4 1- yr ‘he als are the the use other oxides would have as- sisted materially solving the prob- lem the one-coat enamel; but this was found impossible make the cover coat alone adhere the surface, and the importance the ground coat bonding interlayer became more and more apparent. Further trial and error proved that cobalt and nickel oxides were highly essential chemicals bringing about proper adherence ground coat, and while most the theories offered explanation have proved rather er- roneous, cobalt and nickel remain primary components every ground coat enamel composition. Recent find- ings indicate quite clearly that these materials are indispensable for this purpose. should noted, however, that they function only certain amounts for any given ground coat. other words, beyond such point, not possible improve adherence increased content these chemi- cals. Investigation enamel adherence metal base has been hindered the past through the difficulty ascer- taining the exact chemical reaction that takes place between enamel and iron, due the thin sections which must examined. But more recent study with the petrographic micro- scope and the X-ray has disclosed valuable data actual occurrences the interfacial layer. Thus, for prac- tically the first time, theory may based careful observations rather than conjecture. These investigations have shown that during the fusion the enamel - the metal base and the subsequent cooling, alpha-iron crystals are devel- oped within the enamel, and quite likely that this needle-like structure, formed, tends unite the metal and glass, least gives definite aid that direction. Steel manufacturers are familiar with this character metal absorption and the subsequent precipitation the metal from the melt. The reciprocal oxidation and reduction reactions taking place be- tween iron and other metals open- hearth slags case point. Further studies the manner which these alpha-iron crystals are formed the and the effect commercial enameling processes their development present research project considerable importance. possible that the secret ground coat adherence will shown exist the control the formation, size and distribution these crystals. Factors distinctly affecting such for- mation would governed ground coat enamel composition, nature base steel iron, temperature and rate firing, and rate cooling. regard the latter, many ex- perienced enamelers have maintained the past that slower cooling range than customary general enamel- ing plants would far improve the adherence the enamel coating, and future technical findings along this line may tend justify such con- tention. Base Metals not many years ago that sheet steel enamelers encountered much difficulty obtaining suitable base material—sheet steel essen- tial physical qualities withstand the heavy action punching and press- ing, and the strains imposed rapid heating and cooling the enameling process. result, the percentage defective ware was considerable. Through the active research and co- operation different steel mills, this picture has been changed entirely. Suitable base stocks have been devel- oped meet all standard demands, and sensing the possibilities, num- ber the larger mills now specialize sheet steel especially for enameling service. the present time, despite greatly increased requirements im- posed deeper drawing and more intricate product shapes, the enamel- ing plant can readily secure desirable steel stocks from sizable number sources. The chemical properties the steel used for this purpose are less im- portant than the physical character- istics, generally known the industry. recognized fact that steel and iron, well other metals, suitable for various types finish will not serve all for high grade celain enameling. illustrate the vital importance good base metal, recent experience enameling shop using sheet iron particular interest. This plant encountered considerable trouble and loss through black-specking and re- boiling ground coat enamel during the firing the cover coat material. casual check processing pro- cedure indicated lapse customary Transferring work and from conveyor and edgers the plant Detroit-Michigan Stove Co., Detroit. 24—The Iron Age, October 1934 The fire Sta con wal ope the fac cor the ay a The continuous gas- fired dryer, United States Stamping Enameling Co, Moundsville, Va., continues through the wall into the pickling room. care cleaning, dipping and firing operations. became evident that thorough investigation would re- quired. The large number variable factors involved made necessary complete study the different phases production. The ground coat enamel was check- ascertain right type for the purpose, correctly milled and applied proper thickness—all fac- tors that might lead the source the difficulty neglect was evidenced. The cleaning the base metal, well drying and firing ground coat likewise were investigated; the sheet iron was checked source, gage, etc. Elimination these dif- ferent operations one one, follow- ing careful inspection, finally disclosed that the source trouble was the base metal being used. Sheet iron from three different sources showed defects, while such material from three other dicated such difficulty had been experienced. Further check was made trial run, which the various iron samples were enameled and fired under identical conditions. Rejects with the material showing inherent defects through previous analysis, ran per cent, while with the ac- ceptable sheets these averaged only per cent. While proper gage extreme importance base metals enameled, the thickness mate- rial the case issue was not fault; the heavier stocks developed much trouble those lighter gage. Similar experiences connection with cast iron have shown enameling shops this character that the com- position castings great im- portance the production good ware. Foundries have learned that the cupola charge must analysed carefully for the development pro- per castings for this nature fin- ished product. Improper casting com- position may lead readily blistering, black-specking and other serious en- ameling defects. Scrap metal employed must clean, and chemically the cupola mix must mea- sure certain definite require- ments for later effective Standardized and accurately con- trolled cupola practice recognized today the starting point good cast iron enameling, the three most important factors being careful anal- lyis the cupola charge, kind and grade scrap metal employed, and grade pig iron used. Stove manu- facturers, among others, have learned through experience, sometimes costly, that castings applicable japanning are not all suitable for porcelain enameling processes. Enamel technologists have been giv- ing considerable study recently the subject proper base metals, result the apparent relation such costly enameling troubles blister- ing, black-specking, re-boiling and other more minor That many such troubles are purely phy- sical quite evident from findings date. Adequate pickling raw metal shapes another matter prime moment the preparation surfaces for enameling. Shop dirt, rust, draw- ing compounds, grease and other ex- terior blemishes for perfect surface must removed. Proper thickness base material, well uniformity thickness, are other important con- siderations designing the shape and contour the product. one part the material thicker than an- rapidly should the furnace, with the result that the enameled coat- ing that point will not fused completely properly. Where welding employed, seams should developed near pos- sible the thickness the main part the product shape, prevent under-heating the enamel the joints. Ware design, evident, should perfected avoid sharp corners and what may termed, raw edges, the enamel mix will have tenden- run thin such points, likely exposing the metal showing color difference. These are some the fundamental factors, briefly stated, that are well recognized today essential guides successful enameling practice, il- lustrating the definite necessity for comprehensive understanding raw materials and their characteristics. previously noted, porcelain enameling The Iron Age, October 1934—25 Frit smelters and rotary dryer the plant the United States Sanitary Mfg. Co., are gas fired. involves considerations that are not all significant with other types finishing. Blistering With Cast The problem blistering has been one particular concern cast iron enameling plants. The defect, ap- parently, related the base metal employed, although some tech- nologists maintain that this trouble due gases evolved from the enamel itself, and entrapped when the mate- rial hardens. Latest studies indicate this phenomenon developed through the presence certain car- bon compounds close the surface the casting, these uniting with the oxygen the furnace gases pro- duce gases which blister the enamel. Certain iron seems reasonably free from harmful amounts this par- ticular form carbon, others show evidence concentrated form the surface only, while again, there are iron castings with such character carbon well distributed throughout the unit. the latter case, the removal the surface layer sand-blasting not very effective. Research shows that likely that the total volume gas evolved from the iron this way not impor- tant causing blistering, the fact that matures critical point the enamel fusion. Moreover, and rather unfortunately, appears that the same conditions responsible for this harmful and annoying blistering effect may also promote the desired Iron Age, October 1934 adherence the porcelain the metal base. result recent investigation, Emerson Poste, enamel consultant, has concluded that the most desirable type iron for enameling service one relatively high silicon (2.6 per cent). should not analyse more than 0.8 per cent sulphur, will contain phosphorus dependent the pig iron used, about 0.5 0.6 per cent man- ganese, and not over 3.4 per cent total With good foundry practice, this compositional guide should pro- duce non-blistering Such character raw material, pointed out, being employed suc- cessfully for the manufacture en- ameled stove parts. Change silicon content suit different total carbon content might essential for other types castings enameled. Bubbling Plants given over sheet steel en- ameling have been troubled consider- ably with another serious defect, which may may not related blistering, just discussed. This has with the re-boiling bubbling the ground coat, frequently occurring during the firing the succeeding cover coat. The bubbles develop dark spots, impossible eradicate conceal, even with number sub- sequent cover coats. maintained some enamelers that the definite solution this major problem would assist practically all other en- ameling difficulties encountered processing, neglecting those relating shapes and colors, which are rather individual themselves. the case blistering, there decided difference technical opinion the source the gases apparently responsible for the bub- bling. Some enamelers maintain that these gases emanate from the metal base, while others hold that the en- amel, itself, causes the gas formation. Further, there are students the subject who believe that the gas devel- opment individually not much the trouble the physical expan- sion the gas due corresponding physical stresses under the action the furnace. special committee was organized recently the American Ceramic So- ciety for the sole purpose thorough- investigating this important prob- lem, and some definite findings and recommendations are anticipated the near future. Enamel Batch and Composition Good base metal alone only phase good enameled ware, for the proper compounding the enamel glass equal, not still greater importance. While comparativ