The Iron Age 1935-08-15: Vol 136 Iss 7

CHESTNUT AND STREETS, PHILADELPHIA, PA. Sales Offices 239 WEST 39TH STREET NEW YORK, Owned, Published and Copyrighted CHILTON COMPANY (Incorporated) Executive and Publication Offices, Chestnut and 56th Sts., Ps. MUSSELMAN, President FRITZ FRANK, Executive Vice-President FREDERIC STEVENS, Vice-President JOSEPH HILDRETH, GEORGE GRIFFITHS, EVERIT TERHUNE, HASTINGS, WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary FRITZ FRANK, President VAN DEVENTER Editor Managing Editor News Editor Machinery Emeritus Washington Chicago Cleveland Pittsburgh Detroit Boston Cincinnati Contents 15, 1935 Finishing Motion Picture Cameras and Projectors ...... Change Molding Method Reduces Cost Castings... Manufacture Ford Camshafts Modernization Niles Sheet Mill Trailer Frames Fabricated Arc Welding ............ lron Oxide Defects Porcelain Enamel Rate Activity Capital Goods Statistics Metal-Working Activity Construction and Equipment Buying ................. BAUR, General Advertising Manager DIX, Manager, Reader Service Member, Audit Bureau Circulations Member, Associated Business Papers Emerson 311 Union Bidg., Cleveland Published every Thursday. Hottenstein, Otis Chicage tion Price: United States and Pos- Lewis, Woodward Ave., Detroit sessions, Mexico, Cuba, $6.00; Can- Chilton Chestagt Sts., Philadelphia. Pa. $12.00 year. Single copy, cents. ; d n Galvanized Sheets That Are Easy Fabricate reason why Bethlehem Galvanized Sheets are being adopted for host products and cations the ease with which they are fabricated. Their soft, ductile base speeds shearing and bending operations, saving time the shop Their tight, evenly-spangled galvanizing, their uniformity gauge, are other reasons why many manufacturers and contractors prefer them. For superior rust-defiance use sheets copper-bearing Beth-Cu-Loy. Their copper content 0.20 0.30 per cent assures useful life from times long that ‘of ordinary steel, when exposed atmospheric corrosion. | THE IRON AGE ... AUGUST 1935 ESTABLISHED Vol. 136, No. Where A\ngels Fear ganization. coordinate the myriad separate activities which involve sell- ing product, making and showing profit requires ability high order plus thorough commercial and technical training. easy matter plan and manage the affairs successful industrial or- The details managing national economy are many thousands times more complicated than are those the largest industrial business organization. government has yet succeeded carrying out economy," for the simple reason that supermen the requisite ability and experience plan and manage these details have never existed and probably never will. Successful governments, heretofore, have recognized these human limitations and have governed best governing least. Today the trend the other direction. Men who are devoid managerial experience and who have been thrust into governing positions through the exi- gencies mob class appeal are attempting centralize power extent undreamed hitherto even emperors and czars. Such men are dangerous primarily because they are incapable recognizing their own limitations. Their mistakes, made through lack experience, poor judg- ment bad advice, are not acknowledged errors but are attributed organ- ized opposition enemies the people. Thus one instance the Jew becomes the target; another, the thrifty. Amateurism will not work the big business managing national economy any more than will succeed the smaller affairs private business. The reckoning may delayed, but bound come. Even the most inexperienced layman, given dictatorial power, could not ruin General Motors Steel overnight. But give him free hand and enough blank checks and would eventually put these giants their Ex-housepainter Hitler and ex-schoolmaster Mussolini did not lack ex- perience handicap them their ambitions assume detailed dictation national economies, but the people both nations, from present indications, will shortly have pay the piper. America cannot quided past experience, perhaps may impressed current happenings. wat 4 > a Pe li them. 0.30 4% iv a completed camera showing character the damaskene wrinkle finish. metal camera con- struction the problem coverings and fin- ishes necessitated special study. The public had become accustomed leather and leatherette cover- ings and was necessary, from the sales point view well that service, provide finishes that would meet all practical conditions, not alone well the older cov- erings but give something that was actually superior. may contended that after all camera, either the still movie type, spends most its time plush-lined case. However, camera accompanies people when they are play. During the hours being handled the usage rough, even abusive the point destructiveness. satisfactory fin- ish must one that can ap- plied effectively irregular sur- faces. should not necessary modify camera design suit ap- Finishing ZIEBARTH Secretary and general superintendent Bell Howell Co., Chicago must withstand high and low hu- midity, heat and cold and occa- sional ducking creek pond. should not easily scarred nicked. Particular attention now being given perspiration, inas- much known that perspira- tion some people definitely destructive many kinds finishes. Sales appeal must not over- looked. This problem qual- ity shop practices, the judicial areas are protected plugs and covers that are stored wooden blocks which are identified serial numbers. 16—THE IRON AGE, August 15, 1935 sand casting which and | c | { Motion Picture Cameras and Projectors selection colors tints and vigilant check finishes other articles, whether like dis- similar character. For instance, only few years ago number camera manufacturers used baked finish that was described the word “crystal.” was rough finish, desirable camera be- cause its partly non-reflecting characteristics and because the camera felt secure one’s hands. The public liked only too well and time that finish became common, even cheaply made goods many descriptions, that longer belonged high-class merchandise. Once again the hunt was started for new finish. Bell Howell Co., Chicago, man- ufacturer amateur and profes- sional moving picture cameras, projectors and necessary tenances, broadly divides its prod- advent metal finish instead leather and leatherette coverings the production motion picture cameras and projectors has resulted the perfection methods applying and baking metal the Bell Howell Co. plant undercoat heavy-body rubber-finish enamel ered with tung oil base enamel which produces wrinkle fin- ish. Color effects are ob- tained spraying the da- maskene finish with lacquer. Plugs and covers are used protect areas that are not covered the enamel and lacquer. ucts into two classes. Cameras and projectors fall into one classifica- tion. These products fall into both skilled and unskilled and the case cameras abuse may unusually severe. the other hand, there that class equip- ment that used film work shops where all surfaces must smooth and easily kept free dust the possibility dust damage wet film that process. Aluminum die castings and gray iron sand castings are the two products most commonly coated. All these castings are normalized upon receipt from the foundry. They are slowly raised tem- perature 450 deg. F., which higher than any subsequent tem- perature reached the coating processes. This precaution nec- essary because absolutely es- 7 4 sand casting after having been sprayed and Note clean surfaces were protected. THE IRON AGE, August 15, | shop the necessary doors and window openings, the latter being covered with coarse filter mate- rial that air cleaned dust drawn from the main shop. The exhaust fan each booth discharges through short duet the outside the building. These. rooms are actually under slight vacuum. Once week vac- uum cleaner used clean the air filters. All castings, regardless the material which they are made, pass from final inspection after all machine work completed ovens where they are baked 400 deg. This heat removes oil and moisture, and further cleaning necessary before applying the various finishes. Aluminum die castings, such are used cam- and projectors, are given example apparatus that requires smooth finish. This fully automatic double printer used movie studios. booths are well lighted and each one ventilated suction system. sential retain all the refine- ments machine practices and small tolerances which are fun- damental work this character. not wholly impracticable normalize, then coat and finally machine part, but the finished part more likely have better appearance the finish applied last. least eliminates the pos- sibility minor damage during processing the shop. Another point that machine operators complain difficulty setting parts that have been coated before reaching them. Baking Ovens and Booths Protected From Dust The department which houses both baking ovens booths connected the main IRON AGE, August 15, 1935 what termed “damaskene” wrinkle finish. Plugs and Covers Protect Parts That Are Not Sprayed After the cleaning heat has been applied each casting examined for slight imperfections snag and tool marks. When neces- sary these are filled and the cast- ings are then taken bench { } front spray booth. Practically every casting has machined areas that must not sprayed. These areas, sometimes numerous single casting, are pro- tected specially made plugs and covers. Many holes are that ordinary pins are used plug them. Some round hole plugs are mede wood, and others are made brass. Covers for flat machined areas are made metal and are designed for snap fits that they will stay place. All plugs and covers. are fitted with knobs for ease placement and removal the operator. These plugs and covers having been designed for specific part are always kept together insert- ing them holes wooden blocks which are properly identified the part number. When part comes into the finishing depart- ment necessary for the oper- ator call only for the plug block. When delivered him, has that one block all the plugs and covers needed for the job hand. When large number plugs have set before spraying, helper stationed spray booth. The one who does the actual trucks that are pushed into the ovens. spraying assists placing and re- moving the plugs when necessary. Under Coat Rubber-Finish Enamel All plugs being place, the casting placed the spray booth and the under coat applied. This which used primarily for its qualities sticking the metal. The period air drying little consequence. The under coat having been sprayed on, all plugs and covers are removed and the casting placed tray ~ preparatory the baking opera- tion. standard practice this shop start baking operations with cold ovens, slowly raising the temperature the loaded oven, holding the heat for stated time, and then letting the product cool the oven. When load the castings has been sprayed with the under coat placed oven, the temper- ature brought 350 deg. F., which held for one half hour, and then the oven allowed cool, Covering Finish Has Tung Oil Base When the castings are cold, plugs are again fitted and the damaskene finish sprayed on. This heavy body enamel, the base which tung oil, and which ex- pands when placed oven heat. Here again the air drying period not important, when oven load sprayed castings has been oven which slowly raised 200 deg. and held that temper- ature for min. while the wrinkles are forming. the end (CONTINUED PAGE 85) THE IRON AGE, August 15, | + 4 4 | | ‘ : | | j 4 ABOVE tower lead saucer casting. The piece described in. inside diameter and in. depth. The body and flange are in. thick. After machining, the casting weighs 3670 ABOVE 3—Pulley rim cast plate with portion ging place assure correct diameter and depth body core. ° ° ° LEFT 2—Lead saucer mold swept-up. Two arms were used the comparatively shallow mold board assure rigidity and accuracy when pulling the sweep around. Molding Method Red in. thick, with flanged outlet ings, one brick time, was also branch diameter open- prohibitive, but necessary order ing. The weight the casting avoid bruising the face the after machining approximately castings account the metal’s EASTHAM 3670 Ib. extreme ductility. Briefly, when The foundryman favored with made loam, there was not suffi- all this company’s casting busi- margin profit the job, had for considerable time swept observer, whose duty became molds loam, alter matters, with the result that, CASTING pan saucer production which, careful trial, the saucers design, termed, the order the nature and extreme softness poured opensand molds received from company the metal involved, left much with satisfactory results, here- manufacturing explosives and desired. the first place, the inafter described. tower heavy contraction allowance 5/16 saucer casting; material, lead,” per ft. made easily yielding Opensand Mold Procedure shown Fig. The usual blue- mold imperative, cracking spindle socket-plate casting, print giving dimensions and other while cooling were Fig. was specifications accompanied each Another difficulty hard level into pit opened order, but pattern was fur- overcome closed loam mold the foundry floor, the upper face nished, possibly was local shrinkage, heavy the socket plate being set about when request for two three very little use, filling below the intended lowest these castings was placed the “burning up” treatment after re- point the proposed mold. The and diameter varied little. moval the casting from the mold spindle was then greased and low- The example chosen for descrip- invariably necessary. ered into the tapered socket, prior tive purposes in. inside diam- The cost carefully stripping attaching the mold sweep board eter, in. deep, body and flange brickwork away from the cast- the metal arms shown BB. 20—THE IRON AGE, August 15, 1935 | QY li | ABOVE 4—Sprocket design core arbor used the lead saucer castings. Three-point lift facilitates handling when assembling. ° RIGHT 5—Plan and views assembled mold for denitrating tower lead saucer. Cost Lead Saucer Castings Two arms were used the com- paratively shallow mold board assure increased rigidity and ac- curacy when pulling the sweep around, as, due the extreme fluidity and penetrating qualities molten lead, close, hard- rammed mold was necessary counteract the tendency the metal “strike” through the sand when subjected static pressure. tough facing sand consisting new Albany molding sand and floor sand about equal parts, stiffened with little clay and com- mercial dry binder with pitch base, gave added security when generously used the entire mold surface during ramming and sweeping operations. The outlet branch pattern shown correct height before level was reached, the outer face its flange being left open shown permit the branch pattern drawn backward before finishing FOUNDRY regularly re- ceiving orders for de- nitrating tower lead saucer castings had for consider- able time swept the saucer molds loam. Cost production was lowered con- siderably, with factory margin profit, changing opensand molds, herein described. the mold and inserting the branch core when finally assembling the mold. From the floor level the upper face the main flange, 12-in. 4-ft. 6-in. cheek flask part accommodated the remainder the mold, which, incidentally, was extended in. extra metal when truing the flange the machine shop, precaution this kind being advisable when pouring opensand work safe- guard the event the mold being fraction off the level. Sweeping and ations completed, and flat-joirt slicked from the edge the rim the sides the flask, the board and spindle were removed, the hole left the spindle plugged, and the mold finished. segment the flange cut out bandsaw, seen DD, Fig. facilitated finishing the joint the upper edge the rim. heavy coat plumbago blacking rubbed into the mold hand, well into that portion forming the outlet branch nozzle after the pattern piece was withdrawn, was followed wash soluton water and molasses, ratio about prior skin drying the whole area means charcoal fire, under sheet-iron cover. This milder, slower method was used pref- erence the oil spray burner reg- (CONTINUED PAGE 96) THE IRON AGE, August 15, | “ y 22—THE IRON AGE, August 1935 ABOVE shafts are impact tested this special machine. ASTING eliminated most rough machining operations and heat treatment. Success the cast camshaft depends getting structure with cam (chilled) and center shaft soft and strong). tion costs and marked improvement the quality the product have resulted from the manufacture alloy cast camshaft the Ford Motor Co. for its V-eight cars and trucks. Approximately 6000 camshafts are made each working day the Rouge plant the new process, which was introduced about year ago. Most the rough machining operations and the heat treatment savings produc- the camshaft, both which were necessary when forged cam- shaft was used, have been elimi- nated since the product has been the Ford foundry. The main bearings the cast camshaft now show Brinell reading 255 and the chilled cams 418. This means that the sturdiness the camshaft service, already more than ample meet all conditions, has been further increased. Perhaps the outstanding achievement technically has been the perfection the foundry proc- ess making the camshaft that has the desired hardness cer- tain places and desired machina- bility other places when cast, thus doing away with heat treat- ment. Incidentally, the cast cam- shaft the same design the forged shaft. Success the cast camshaft de- pends getting structure with the cam tip hard (chilled) and the center the shaft soft (machin- able and strong). the shaft cast ordinary green sand molds, the depth the chill and the strength and quality the gray iron core dependent the an- alysis the metal, the coke ratio, the pouring temperature and the amount moisture the sand. Analysis Mixture The cast camshaft the fol- lowing analysis: Carbon, 3.30 3.65 per cent; manganese, 0.15 0.35 per cent; silicon, 0.45 0.55 per cent; chromium, 0.00 0.25 per cent; copper, 2.50 3.00 per cent; and phosphorus, 0.05 per cent maximum. Two standard cupolas are used melt the charge, which com- prised 320 lb. Bessemer pig iron, 400 lb. camshaft back stock, lb. steel scrap and copper. The pouring tem- perature 2600 2650 deg. The cupolas are lined down in., the coke bed being in. high. Between each charge 8-hr. cycle 125 coke added. the fifth charge extra pounds i 4 3 4 } | | 7 | q me ify i @ to j i be d 4 in 7 j 3 And Cuts Costs Casting coke used. double charge other 12.30 Air pressure put about tons per cupola every hr. Hot metal tapped from the ABOVE PERATOR pulls ladle hot metal monorail conveyor point near pour- ing station, where metal transferred hand poured. Note inspector carefully checking pended from overhead monorail conveyor. operator pulls the full ladle hand point near the pouring station, where the metal transferred hand ladles poured into the molds. Two castings are produced each mold. There core the front end each shaft for the undercut the end the shaft aid machining and grinding the face. The mold conveyor oval shaped. Castings are poured the molds move slowly along this conveyor. Along one entire side the conveyor ventilating hood has LEFT ORTY-ONE chining operations necessary cast camshaft, com- with merly the camshaft. Here the main being rough ground centerless grinder. THE AGE, August 15, | i — 2 ts 3 been installed draw off gases from the molds and the shafts. the far end the conveying unit the shakeout. the space be- tween the shakeout and the pour- ing station battery modern molding machines, where molds are prepared for the casting oper- ation. Samples each heat are: taken pouring bars in. diam- eter. After cooling, the bars are fractured and the depth the chill noted. the chill appears in- adequate, powdered ferrochrome 0.25 per cent added the ladle. the other hand, the chill the test sample too deep, small amounts powdered ferro- silicon are added. operator constantly work noting the frac- tures and adjusting the chrome and silicon contents give the proper chill. flat vent, 1/32 in. thick and wide the cam tip, run in. from the point the cam start the chilling ac- tion the No. cam point, which near heavy section. Cams should file hard the tips. All camshafts are impact tested dropping 3-lb. 8-0z. weight in. the center main bearing, the shaft being supported during the test the end main bearings. The test severe that will break shafts with small cracks shafts which are too brittle. When the forged camshaft was used there were machining op- erations the rough forging. connection with the present cast camshaft, only machining op- erations are necessary: The only actual cutting operations are the machining the construction slot, the cutting the timing slot and making the centers for grinding the cams. the white iron hard tips the cams which are responsible for the maximum service given the cast camshaft. Over 809,000 cast shafts now are Ford V-eight cars the hands the public and difficulty has been experienced connection with them. Lateral Steel Reinforcement Strengthens Brick Columns SERIES tests recently con- ducted the department mechanics the University Wisconsin determined the prop- erties reinforced brick masonry columns and the results are con- sidered great importance the building industry. The tests showed that the effective strength re- inforced brick masonry column | 4 qt THE strongest column brick tested. Steel hoops placed the horizontal joints added the applied before the column failed. 24—THE IRON AGE, August 15, 1935 equals the sum three compo- nents: the strength the plain masonry, the strength the longi- tudinal steel its yielding point and the lateral restraint given steel hoops placed the horizontal joints brick column. Lateral hoops every joint served increase the toughness and some extent the strengths HIS reinforced column had lateral hoops. the columns. The yield point the %-in. steel rounds used the hoops was 53,800 per sq. in. The strength the fillet and spot welds the 10-in. hoops after heat- ing 900 deg. (1652 deg. F.) and straightening while hot aver- aged 58,900 per sq. in. bar cross-section. Spot welds alone did not prove satisfactory. brick masonry column had reinforcement. | | | | { | Model Kitchen Briggs steel plumbing division the Briggs Mfg. Co., Detroit, which just getting into pro- duction the company’s com- pletely rehabilitated Hamtramck plant, exhibited Chicago recent- the model kitchen shown this photograph. The kitchen cabinet sink example drawn metal construction which has started new trend plumbing style and utility. Sinks are available any color color combination desired; the enamel acid resisting. The small unit the left the sink dish-washing machine devel- oped Briggs. the right the sink the new styling refrigerator Briggs. the foreground round electric stove created Briggs engineers suggestion the industry. The stove rolls castors and per- mits cooking from any angle. The new drawn-metal plumbing ware and stove proved the out- standing sensation the national plumbing show, more than 40,000 persons having seen the exhibits. Briggs likewise displayeda model bathroom the plurabing show, with all the plumbing ware, including the bath tub, made stamped steel. The new plumbing ware streamlined and ultra-modernistic every detail. Building stylists believe that this new mode styl- ing will provide important ap- peal and stimulus reviving ac- tivity replacements and the construction industry. q 3 i THE IRON AGE, August a é” 1 3 4 § i ; i 3 j i 4 q 4 and Economy PRENTISS Cleveland Resident The Age tional manually operated sheet into mechanized and modernized well highly flex- ible plant, has been accomplished the Niles Rolling Mill Co., Niles, Ohio, which has converted the old Falcon plant that city into low-cost plant for the manufacture sheet specialties. The provision plant that will produce material the highest quality has been one the aims the company. Outstanding among the new equipment installed three-high roughing mill new type, which another indication recent trend toward three-high roughing mills. Another feature the two- high finishing mills which are fully automatic controlled, with mechan- ical tables, etc. Plant Completely Modernized Adopting the view firmly held many that there still place the sheet steel industry for mills that mechanization can reduce their costs that they can com- pete successfully with large four- high continuous mills, and that many orders are not large enough roll economically continu- ous mill, the Niles company devel- eped its plans revamp its plant with the most modern types mills, mechanical feeders and catchers’ tables, furnaces, convey- ors, annealing, continuous pack shears and other equipment or- der improve the quality the 26—THE IRON AGE, August 1935 product and effect saving labor costs. This plant, last oper- ated the former Empire Steel Corpn., was modern full-finished, auto body, manually-operated plant the time was shut down 1931. The Niles Rolling Mill Co. purchased this plant and has con- verted into up-to-date mech- anized plant the expenditure nearly $500,000 new equipment. terne, galvan- ized and sheets will the specialties made the re- equipped plant, which was placed operation the middle July. However, the products will include full range sheet finishes and widths in. wide and from gages. The three-high roughing was installed substitute for the conventional two-high mill order effect economies taking heavier reductions, get uniform gage and quality, and increase production. This mill will use sheet bar in. wide com- pared with the usual 12-in. bar, and the management expects able increase this 24-in. bar and has hopes cutting down the number passes necessary for breakdown from five three. Backtracking Material travels one direction the new layout, thus avoiding backtracking, while ease chang- ing from one product another adds flexibility. One all the finishing mills may con- veniently operated one time. Practically the old hot mills, consisting roughing and eight finishing mills, have been scrapped and replaced two fin- ishing mills, one combination fin- ishing and roughing mill and one three-high roughing mill which will produce 5000 tons per month. While three the four mills were rebuilt, little from the old mills was used except the housings. Roughing Mill Three-High Unit The three-high breakdown unit 56-in. mill capable roughing four pairs sheet bar per minute. Two bars are broken down time, being first given two single passes and then three matching The three-high roughing mill balanc | ' 8 a | | > passes. 16-in. wide sheet bar reduced five passes No. gage breakdown the desired thickness for the finishing mill. Operations are based 16-sec. cycle from the start the cycle the five passes the beginning the next. The roughing mill and also the three finishing mills are driven 1600-hp. General Elec- tric motor r.p.m. and the sequence operations the mill. The front and back tables, the screwdown and the furnace con- veyors are synchronized the basis the motor speed. The mill and its tables were built the Continental Roll Steel Foundry Co., Pittsburgh and Chi- cago. The mill has fully balanced top and middle rolls and said the first fully balanced three- high roughing mill installed the United States. The top and bottom rolls are driven and the center roll floating roll. The top roll bal- anced spring suspension and the center roll mechanical mech- anism. This middle roll raised and lowered motor-operated eccentric which actuates four rods located along the inner posts the mill housing, one each corner. Rolls Balanced Prevent Slippage Balancing the two rolls, claimed, will prevent slippage and spalling the center roll and as- sures better control than the fric- tion driven three-high mill. also claimed that with the top roll driven, heavier draft can taken the back pass than with friction-driven mill. Being wet mill, pointed out that the shape the bar can better con- trolled than the ordinary two- high mill. The mill expected make per cent reduction the sheet bar both the top and bottom pass with slippage. production 1700 1800 pairs 8-hr. shift, approximately tons, expected this mill. The top and bottom rolls the three-high mill are in. diam- eter with 56-in. face. The roll neck diameter in. The working center roll in. diameter 58-in. face and has 12-in. diameter neck. Bearings for the top and bottom rolls are Ryertex water type. Anti-friction bearings are used the middle roll. Clark-Type Screwdown Control The screwdown drive consists two motors, one for each screw, coupled together. The screwdown control, which the Clark type, semi-automatic and is, stated, the first installation this type screwdown control the United States. The control per- mits the taking five seven passes through the mill. Con- trol the mills, tables, furnace conveyors and screwdown two operators, one located each side the mill. The control equipment was supplied the Clark Con- troller Co., Cleveland. The roughing unit has sta- tionary table front and tilting, air-cushioned back table, and the speed the tables, previously stated, synchronized with the mill speed. The mill and tables are interlocked that pass can not enter the mill unless the back catching table its proper position and the position the center roll controlled the posi- tion the back table. Bar-Heating Furnace Has Capacity The bar-heating furnace, which natural-gas fired, ft. long and has the capacity for heating tons per hour. This furnace and also the pack-heating furnaces are the Flinn Dreffein type and were built Wean Engineer- ing Co., Warren, Bars are stacked crates the bar shear and carried overhead crane Mathews Conveyor Co. grav- ity conveyor extending along the side the furnace, which they move the charging erd the furnace. Another gravity veyor front the furnace moves the bars the point where THE IRON AGE, August 15, 1935—27 din Modernization Niles Sheet ° ° ° balanced top and middle rolls J they are picked the furnace conveyor chain. Emerging from the furnace, con- veyors carry the bars the sta- tionary table front the rough- ing mill, and after the mill makes complete cycle passes the break- downs are delivered another con- veyor the charging end the finishing furnaces. Automatic Mechanical Feeders and Catchers Serve Finishing Mills The two finishing mills are served automatic mechanical feeder and catcher tables built the Wean Engineering Co., War- 28—THE IRON AGE, August 15, 1935 ren, Ohio. the steel goes doubler the catcher side the finishing mill and re- turned the charging end the pack furnace roller conveyor that, starting beneath the floor front the doubler, extends along the side the pack furnaces and carries the sheet back the charg- ing platform for second passage through the furnace and again the finishing mill. The pack fur- naces are the chain type, ft. long, with capacity tons per hour each for single heating, tons for double heating. The third mill the finishing department roughing and finishing mill for starting with the sheet bar and rolling material gage and heavier that finished one heat- ing. This served continuous bar and pack furnace. The two finishing mills and combination mill have been equipped with con- tinuous The cold-rolling equipment con- sists three separate drives with Packs are sheared Streine pack shear made the Streine (CONTINUED PAGE 98) LEFT finishing mills are served ical feeder and catcher tables. BELOW ARS crates the bar shear and are then transferred overhead crane which moves them the charging end the furnace. Here an- moves the bars point are picked the conveyor chain the bar heating furnace. tic the pa 16. | Trailer Frames Fabricated A\rc Welding NCREASED strength and lighter weight, together with savings cost, are said result from the use welded steel construction the manufacture trailers the Available Truck Co., Chicago. Three sizes trailers, namely and ton, are built the com- pany. Standard frame lengths are 16, and ft. respectively, but other lengths are available. Frames all models are in. wide and in. deep rear and in. deep front. Standard mild shapes are used wherever possible construc- tion the trailers. The frames IG. trailer frame the plant the Available Truck Co., showing clamps used for holding struc- tural gether. consist two longitudinal mem- bers and six cross members. Spring brackets are bar steel electrical- welded. The main longitudinal members range length between and ft., depending the size the trailer. These members are in. wide all models, with thickness 3/16 in., in. and 5/16 in. re- spectively, for the and 10-ton types. Cross members are 41%, 41% and 41% in. Widths are in. each case. The thickness cross members the same that the longitudinal members. Construction these trailers extremely simple, consisting mere- assembling the frame chan- nels, squaring them and clamp- ing place. sufficient number clamps and spacers are used order assure correct dimensions and proper alinement. With the various members clamped posi- tion, they are tack welded together various points. (See Fig. 1.) The clamps are then removed and the whole frame welded into one rigid piece steel, shown below. Shielded equipment supplied the Lincoln Electric Co., Cleveland, employed the welding. 2—A complet- frame con- structed entirely shielded arc weld- ing. Increase strength, with sav- ing weight, was obtained. THE IRON AGE, August 15, 4 Copperhea CONSIDERABLE number articles have been written about the copperhead defects which occur times porcelain enamel. Most these articles have been based few plant experi- ences and the control methods which are given are those which prevented the defect certain plants. many different things have been proposed for cure that the information confusing unless the fundamental aspects such defects are kept clearly the fore- ground. hoped that this discussion will tend clarify some the previously published work through presentation the fundamental considerations which account for the formation copperheads. some, this presentation the mechanism may not new, but there appears recorded discussion the mechanism which study. Thus this discussion of- fered order give under- standing the fundamentals copperheading. Copperheads are so-called ac- count the bronze copper color which often exists these defects. Crystals iron oxide have been identified the cause bronze copper color. Not all copper- heads are this color, but many them may appear gray iron oxide spots with free scale the center nearly covered with enamel. Thus copperheads may defined those defects enamel which are caused local spots excess iron oxide. They are the spots which show iron oxide either gray material which has never dissolved bronze colored spots which result from crystallization iron oxide from enamel. There occur, course, all degrees oxidation from little none excessive amounts, and thus there may all degrees copperhead- ing defects. 30—THE IRON AGE, August 15, 1935 4 q Underfired ground coat enamel. The light area the metal and the dark area enamel. Note the undissolved iron oxide the junc- ture. Taken 500 diameters. this point would well give description the normal firing conditions enamel order clearly understand the forma- the regular normal ground coat firing process, there oxidation the surface the sheet layer, the thick- ness which few ten thou- enced such things particle size the enamel, thickness coat, duration time the ware the temperature range be- low the fusion range the enamel the time that the metal exposed the oxidizing at- mosphere the furnace well the nature the metal itself. quite well known that the dried ground coat, the iron be- fore fusion, exists layer made particles packed together. During the first short heating interval, moisture and gases are liberated. This moisture was not freed the previous drying because chemical combination. result the film enamel cracks much the same clay bed drying and the shrinkage will crack. The gas evolved also forms openings. Oxidation Proceeds Until Enamel Fuses ground coated panel which has been fired fairly hard one end and fire other will show stages burning. Thus the ap- pearance various stages fir- 2.—Underfired ground coat enam- 500 diameters. Note the bubbles the enamel. There still some undis- solved oxide the interface. | | | | | ° ing h the cee air : 4 ope | ere 4 | \ | | ' | | ing the enamel and particularly the crack crevice stage may noted. Oxidation the metal pro- ceeds through the infiltration air the metal through these openings. This oxidation proceeds until the enamel has fused cov- ered the surface. Methods have devised whereby the enamel glass and the metal itself may polished cross sectionally and intact that their structures may microscopically examined. cross-section one sample enamel and meta! much underfired state shown Fig. The light area the metal and the dark area the much undissolved iron oxide exists between the enamel and the metal. Another much underfired sample shown Fig. with many small bubbles and undissolved oxide the interface. the enamel fuses, there first formed solid mass with practically bubbles. Then small bubbles begin form and are liberated escaping from the enamel, and fusion continues the iron oxide layer absorbed the enamel. Fig. shown section sample where the iron oxide has been dissolved, forming layer which appears dif- ferent from the other enamel when ° ° ° 3—A normal enamel seen sec- tionally 500 di- ameters. The so- called layer iron oxide so- lution with the enamel extends from the juncture. The enamel shown here the dark area, whereas the base metal the light area. ° Porcelain NAMELERS usually exer- cise their art under care- fully controlled conditions. Nevertheless, occasional de- fects will appear. discouraging copper- heading, the reddish brown spots which often ruin sheet iron ground coat enamels. The author herein discusses the factors causing this iron oxide defect, and reviews the various practices which copperheading. examined the microscope. This has been called “hazy” layer, and solution iron oxide the enamel. has different light-re- flecting properties than the other portion the enamel. the firing proceeds, the bub- bles the enamel layer become fewer and larger until, the firing period, they are the average about one-third the thickness the enamel coat approximately one-thousandth inch diameter. Peculiarly, most all the bubble distribution toward the outer surface the ° CANFIELD American Rolling Mill Co., Middletown, Ohio enamel above what has been called the hazy layer. Longer firing bubbles, some which are prac- tically large diameter the thickness the enamel coat itself. These, course, are sources weakness and may indicative that the enamel was fired rather hard. High Oxide Causes Crystals interesting that layers iron oxide may covered enamel, but good adherence de- veloped only when the free iron oxide has been practically all absorbed the enamel. the enamel able readily dissolve all the oxide, good adherence may obtained while, with excessive amount oxide, poor adherence may expected. Ex- cessive amounts oxide may cause crystals form enamel. The desirable enamel structure one with little undissolved oxide the interface and with the so-called hazy layer penetrating about one-third the way from the metal the surface the ground coat enamel. generally considered essen- tial that some iron oxide formed during the firing order that good adherence obtained. considered that iron oxide dis- solves the enamel and, with the aid the adherence oxides, at- tacks the metal give mechanical and chemical attachment. Before the structures copper- heads are discussed, one series experiments might advantage- ously commercial enamel was fused with iron oxide crucibles with iron present. Mixtures varying amounts were made. These melts were milled pass through 200-mesh screen and cones made each. The softening points were determined THE IRON AGE, August 15, ° ° ; ; q : : 1460 1340 1100 4.— Effect iron oxide enamel. Note that the enamel has critical softening point which deter- mined the quan- tity iron oxide Per Cent(Iron Commercial Low Borax Enamel (16.8 Per Cent per min. and the softening point determined the point which the cone tip reached the base. These relative softening points with different enamels gave curves such shown Fig. The softening point plotted against per cent weight iron oxide the enamel. noted that small per- centages iron oxide lower the softening point the enamel and that further amounts iron oxide have little effect until the soften- ing point sharply increased. Iron oxide about per cent will raise the softening point far above the range ordinary enameling temperatures. With the compositions where the softening point raised the presence iron oxide, was noted microscopic examination that crystals iron oxide begin ap- pear, and the higher the softening point the greater the increase quantity oxide crystals. IG. the upper left shown solution 16.8 per cent B,O, and per cent higher percentage iron oxide (22 per cent) causes sepa- ration some iron oxide crystals, shown the upper right view. the left shown enamel con- taining per cent iron oxide. Note the many crys- tals which have separated. All microphotos 500 few photomicrographs will lustrate this more clearly. Fig. shows section through one the cones which contained enamel with 16.8 per cent B,O, and per cent appear this concentration, the enamel able hold solu- tion this quantity oxide. The same enamel composition (Fig. with per cent shows some iron oxide crystals separated cause saturation. The same enamel composition with per cent iron oxide has many separated crystals. For comparison, Fig. shows enamel composition with 22.5 per cent and per cent which few crystals iron oxide have separated. This same enamel composition with per cent iron oxide also shown. readily noted that this enamel able dissolve more iron oxide and the fusion range correspondingly in- creased account the increased boric oxide content. Oxidation Occurs Three Degrees The mechanism which the iron oxide crystals form some- what follows: The iron oxide more higher tempera- tures than lower temperatures and when more oxide has dissolved while the higher temperature than could dissolved the lower temperature, then crystallization separation iron oxide crystals will occur cooling the lower temperature. Thus, the concen- tration amount iron oxide dissolved and its different solubil- diameters. 1660 1540 | 1500 = c 1380 300 1260 c | 32—THE IRON AGE, August 15, 1935 6.—Enamel composition having higher boric oxide content. the left the iron oxide content per cent and the right the content per cent. The increased boric oxide content enables the enamel dissolve more iron oxide. ity the different temperatures control whether crystallization will From the fact that iron oxide crystals have been identified copperhead structures iron oxide crystals cause the fusion point raised, reasonably follows that the presence the relatively infusible oxide crystals the explanation for the rela- tively infusible mass that exists most copperheads. For convenience discussion, oxidation may considered oc- curring three degrees, namely, normal oxidation, oxidation insuffi- cient saturate the enamel even cooling, and excessive oxidation. The first degree oxidation may considered the nor- mal layer oxide which forms the early stages the enamel ground coat firing. The action this the normal firing process has already been discussed. The second degree oxidation may considered the forma- tion mounds iron oxide local spots thicker layer and not sufficient quantity satu- rate the enamel even the lower temperatures. this oxide exists mounds, may dissolve and 8.—Two sectional views—at diameters above and 500 diameters the right—of raised cop- perhead. Note that the excess oxide less than for the depressed copperhead shown Fig. pressed copperhead. The dark area enamel. Photo taken 500 diameters. the bubbles, leaving darkened spot and what might called ously noted that small amounts iron oxide lower the softening point and these dark spots the enamel are where local oxide spots have dissolved and the enamel give dark, depressed, bubble-free spots. The iron oxide this spot has usually all dis- solved and remains solution and noted that there are other causes similar appearing depressions enamel and that the appearance such spot not absolute proof that iron oxide was the cause, The third degree oxidation may considered that amount oxide which will overload the enamel. This amount may high- localized and give copperhead structures iron oxide defects. There may present only suffi- cient oxide saturate the enamel and form few crystals cools, but often there sufficient oxide saturate the enamel the enam- eling temperature and leave some undissolved the interface. The oxidation may have been sufficient leave exposed scale around which the enamel has attempted flow. The essential difference “raised” and “depressed” copper- heads the amount excess ox- ide present. Those depressed have larger local spots excess oxide. THE IRON AGE, August 15, 1935—33 4 . = 4 i : 4 ‘ H i J section through depressed copperhead shown Fig. Fig. shows two views sec- tion through raised copperhead. oxidation the chief difference. should also noted here that general bronzing surface the ground coat result gen- eral excessive oxidation rather than excessive local spots. When ware de-enameled, found that copperheads leave the metal etched slightly pitted condition. This irregularity occurs even though the copper- heads may have been produced several different causes. The amount pitting apparently dependent the amount oxida- tion and reaction dissolved oxide with the metal. The etched pit may ring with essentially roughen- ing the center. Such pits may produced various degrees disturbance use pin the dried ground coat before firing. Excessive oxidation decreases the fluidity the enamel, which ex- plains the etched pit structures. The metal attacked only where the enamel can dissolve the oxide and remain relatively fluid, thus the attack around the edges spots excessive oxidation. The pitted effect not the cause the defect, but the result and evidence excessive oxidation. Many Causes for Copperheading explanation all specific cases copperheading iron oxide de- fects. is, however, beneficial discuss some observations spe- cific cases order that preventive measures may readily devised after consideration the mecha- nism formation. The diagnosis the specific cause often obtained only after few directed experiments since the actual evidence usually de- stroyed during the ground coat firing. There may enumerated many different specific causes copper- head defects. Some these are insufficient cleaning, thin enamel coat, metal surface, improper dry- ing, heating rates, furnace atmos- pheres, enamel characteristics and plant processing conditions. These are inter-related through obtaining the condition whereby excessive local oxidation may occur. occurs, 34—THE IRON AGE, August 15, 1935 usually the first changes effort control are made with the cleaning process. The effect cleaning the metal insure that the enamel will wet the surface well slightly roughen it. smooth surface does not wet readily enamel does rough surface. The function the clean- ing process remove dirt, grease materials which the early stages firing will tend open the enamel coat and promote excessive oxidation. considerable number obser- vations have shown that most cop- perheading prevented good cleaning practice. Often, merely scrubbing the surface the ware the enamel slip will prevent the excessive oxidation either re- moving material from the surface and giving thorough wetting increasing the weight enamel carried. Instances copperheading also have been noted which one metal surface was less readily cleaned than another the surface carried less enamel than another and the excessive oxidation occurred the less readily cleaned metal. Instances copperheading have been noted which one metal stock showed excessive local oxida- tion more readily than other stock being run the same time. the greater instances the cause was insufficient cleaning the metal surface with the some- times added condition that the metal carried thinner coat is, therefore, desirable that the cleaning process such that the surface slightly at- tacked and left clean. There have been many instances which attempts use thinner coat have resulted many spots excess oxide formation. Merely increasing the weight ground coat has eliminated the trouble. The metal surface, above, factor the weight enamel carried and this affects the oxidation. Carbon the sur- face will tend promote excessive oxidation keeping the enamel open. This may noted some cases primary boiling. Heating Rate Important Rusting from improper drying will tend give spots excessive local oxidation. quite inter- esting that the hollow ware in- dustry mottled effect produced some the ware production some localized rusting. These rust spots are controlled found additions the slip. This mottled effect from rusting ob- tained the fact that the oxide, and the enamel fires down differ- ently the various areas. The rates heating the metal through range below the fusion the enamel affect the quantity oxide formed. well known that oxide defects are more readily produced some furnaces than others and this appears re- atmosphere. Firing tools and fur- nace load are also factors heat- ing rate and influence the oxida- tion. Different furnaces have sometimes given different results the same stock and this prob- ably was associated with heating rate. Several experiments are recorded that moisture the furnace at- mosphere affects the oxidation the Wet ware entering the furnace and non-ventilation the furnace have some cases been associated wit