The Iron Age 1945-07-19: Vol 156 Iss 3

VAN DEVENTER President and Editorial Director BAUR Vice-President General Manager LEONARD Assistant General Manager HAYES Advertising Manager JOHNSON, Manager Reader Service and Market Research BAUR, Production Manager CLEARY, Technical Research and Promotion Manager ° ° Executive Offices Chestnut and Philadelphia 39, Pa., U.S.A. Editorial and Advertising Offices 100 East 42nd St., New York 17, N.Y., Business Managers New York New York 100 42nd St. 100 East 43nd Cleveland 1016 Guardian Bidg. Park Philadelphia Chilton 1134 Bidg. PEIRCE LEWIS WARREN Detrolt Hartford Conn. 7310 Woodward Ave. Box RAYMOND KAY Los Angeles 2420 Cheremoya Ave. Owned and Published CHILTON COMPANY OFFICERS AND DIRECTORS MUSSELMAN, JOS. HILDRETH, President GEORGE GRIFFITHS Vice-President EVERIT TERHUNE Vice-President VAN DEVENTER Vice-President BAUR Vice-President FAHRENDORF Vice-President WILLIAM BARBER, Treasurer JOHN BLAIR MOFFETT, Secretary JULIAN CHASE HARRY DUFFY BUZBY THOMAS KANE CHARLES HEALE WILLIAM VALLAR, Asst. Treas. Member, Audit Bureau Circulation Member, Associated Business Papers the Industrial Arts Index, Pub- lished every Thursday. Subscription North America, South America and Possessions, $8; Foreign, year. Single Copy, cents. ° Copyright 1945, by Chilten Company (inc.) IRON AGE Vol. 156, No. Editorial The Can and Can’t Doners Technical Articles Controlling Quality Steel Castings Plastic Tooling Procedures Precision Founding (Part Formation and Structure Iron Oxide Films Influence Overaging Aluminum Alloys Magnetic Holddown Chucks New Equipment Features News Front Assembly Line Washington West Coast Personals and Obituaries Dear Editor This Industrial Week News Industry News and Markets Contract Terminations Reach Billion New Business Offsets Terminations The Bogey Economic Maturity SAE Training Highway Construction RFC Subsidiaries Merged RFC Handle Surpluses Tool Engineers Advise Low Milling Speeds Patent Seizure Yields $150 Million Machine Tool Market Developments Nonferrous Metals News and Prices Iron and Steel Scrap News and Prices Comparisons Prices Week and Year Finished and Semi-Finished Steel Prices Warehouse and Steel Prices Iron and Steel Pipe and Tubing Prices Exceptions Steel Price Schedule Pig Iron and Coke Prices Bolts and Nut Prices Stainless Steel and Ferroalloy Index Advertisers July 19, 1945 112 114 116 118 120 124 132 136 144 146-7 148-9 150 152-3 154 155 158 159 160-1 258 ‘ | | | £ 4 | «| ° ° ° » ° ° +k Mahon’s reputation for fabri- cating finer welded machine bases from steel plate long standing. Today, that reputation has extended into scores other industries, pro- ducing endless variety products, ANT NOW FABRICATED FROM Welded steel plate fabrication, like many other methods and processes confined limited use before the war, has broadened out into widespread adoption. Industry after industry has found that many different parts and products could built better, faster and, many instances cheaper from steel plate. conse- quence, they have switched this stronger, smoother construction with its attendant savings scrap—in finishing time—and the elimination bulk and weight. Mahon has played prominent part this pioneering work—developing one the finest equipped steel plate plants the country. you are interested the possibilities welded steel plate fabrication—as applied your product—you will find the long and varied experience Mahon engineers very real assistance. Address inquiries STEEL PLATE DIVISION THE CHICAGO . | | i | PROD | | | a | | | | | | : Fabricators Machine Bases and Frames and Many Other Welded Steel 46—THE IRON AGE, July 19, 1945 nfined could conse- ith its and loping sted stance. ESTABLISHED 1855 ° ° July 19, 1945 ° VAN DEVENTER President and Editorial Director BAUR Vice-President and General Manager Staff Technical Editor ........ OLIVER ° ° News Editor JACK HIGHT © ° Associate Editors WINTERS ALBIN JOHN ANTHONY BARMASEL Editorial Assistants DAVIS LLOYD Pittsburgh Park Bidg. POST Chicago Otis Bidg. EUGENE HARDY ANSBORO Washington National Press Bidg. LLOYD Cleveland 1016 Guerdian Bidg. BRAMS Detroit 7310 Woodward Ave. OSGOOD MURDOCK WORTH HALE San Francisco 1355 Market St. Editorial ROBERT McINTOSH DEAN Buffalo FRAZAR Boston HUGH SHARP Milwaukee Toronto, Ont. RAYMOND KAY Los Angeles John McCUNE Birmingham ROY EDMONDS St. Louis JAMES DOUGLAS The Can and Can't Doners HERE are many different kinds people that pretty hard classify them except physical characteristics. And that not important mental outlook. course, you look inside people’s heads, you find ex- tremely varied range thoughts but and large you can put everyone into one two pigeonholes according his thinking. One these would labeled “The Can-Be-Doners” and the other “The Can’t-Be- Doners.” The residue, after this sifting, consisting those who don’t think all you could drop into the waste-basket except for the fact that they vote and therefore have hand determining national policies. The Can-Be-Doners must not confused with optimists who invar- iably wear smile and think things are hotsy totsy. Most Can-Be-Doners have sense enough recognize that things can very bad indeed not nearly good enough, but have guts enough determine make them better. One degree possibly degrees worse than the optimist the egoist. believes that anything can done, “but only and the Grace God.” glad that President Truman just Can-Be- Doner who believes surrounding himself with capable assistants the things that can and should done. have never known successful businessman, industrialist, inventor, labor leader leader our Armed Forces who wasn’t Can-Be-Doner. Nor have ever known business being built from the ground Can’t-Be-Doner, successfully perpetuated one. the other hand have seen many that have been utterly ruined because one these chaps crawled into control through upper story window in- heritance other accident. why all this foregoing fuss and furor about the Can’t-Be- Doners? You might say that they never have amounted anything anyway and never will. The answer that is, that the comparatively few Can’t-Be-Doners who are capable thinking have evolved philosophy that mighty attractive the millions more them who are incapable thought. the defeatist doctrine economic maturity. Their thesis that nearly everything has been done that can done and that from now our economy must static instead dynamic. Old “Doc” Townsend California gave them the idea how popular this thought could his campaign for “Forty week after fifty.” Then along came Lord Keynes England, advocate accumulative national debt; Dr. Alvin Hansen, this country, echo the thought; and bad boy economist—but clever publicist, Stuart Chase, who wanted swap the Constitution for technocracy. These and hundred little brains the late and unlamented New Deal gave voice the doctrine economic defeatism. And into their camp swarmed motely assort- ment regimenters, regulators, political buzzards who hoped fatten decay and horde hand-me-outers. You who read this page, and the other pages this and other journals, whose function help people more are all Can-Be- Doners. And you will glad know that your belief bigger and better America substantiated facts. You can find them “The Bogey Economic Maturity,” George Terborgh, recently published the Machinery Allied Products Institute, 221 North Salle St., Chicago. It’s must for Can-Be-Doners. 4 SCHIEN MILLER | Inland scarfer work Inland “Flame Throwers” Help Make Better Steel Scarfing with oxy-acetylene important mills, where slabs and blooms, rolling procedure the Inland mill because heat, are scarfed clusters oxy-acety- helps assure satisfactory surface. lene torches. These then pass contin- some cases rolled forms, such the blooms uous sheet and strip mills. shown above, are hand scarfed before ship- one the many modern ment. other instances the steel auto- methods used Inland produce quality matically scarfed while hot and while steels, still the mill. Examples Inland Steel Company, Dearborn scarfing can seen the Inland blooming St., Chicago Bars Floor Plate Piling Plates Rail Reinforcing Bars Sheets Strip Structurals Tin Plate Track Accessories Sales Offices: Cincinnati Detroit Indianapolis Kansas City Milwaukee New York St. Louis St. Paul 48—THE IRON AGE, July 19, 1945 News Front July 17, 1945 The new postwar jeep announced this week will combinal vehicles the low price range which production starting. cultivate certain row crops which the tread width not suitable. the the jeep has drawbar pull 1200 and the highway pulls trailer load 5500 with adequate reserve power for grades. Marketing will through stre ened organization. Despite the close approach United Nations troops tin producing regions the East Indies, will minimum two years after conquest before quantities tin can exported into the United States. Meanwhile, can ticipated that restrictions the use tin will drawn even tighter WPB. While chromium has long been considered critical material WPB, imports reported have dropped significantly during the past half-year due the ment import certificate that artificially limits importation. member the SPB has proposed that western corporation, publicly finance established for purchase and operation Geneva, and perhaps Fontana. Gen od not purchased western corporation, possible that the government sider closing it. new study the Geneva Steel potential markets, Dr. Mahoney stresses portance the western tinplate market divided between canners and dominated eight integrated steel companies. His conclusion that Geneva should complement and not compete with other steel plants. suggests that the sale price the plant could based value per ton usable capacity, and periodically reappraising the value plant according percentage capacity the market could absorb. Postwar plans Canadian manufacturing industry call for widely dispersed construction. $1.5 billion expended for war plants believed that most plants can utilized for postwar industry. There some speculation among members the SPB that coast aluminum plants might converted into steel fabricating plants and become part western steel industry, and that shipyards might make excellent auto assembly British industrialists have far-reaching plan assist the revival and sequent maintenance export trade. The industries have establis their own organization for conducting market research and maintaining trade int gence service throughout the world. This British Export Trade Research Organization, the so-called Betro, will headquarters and branches every overseas territory. London also will "flying squad" expert research personnel ready overseas short notid carry out market research any given territory. The Skoda Works, Pilsen, Czechoslovakia, was hard hit Allied bombs almost the last day the war. The Czech Ministry Industry reported the plant about per cent ruined, but such reports always bomb damage and later iny gation shows the plant for the most part superficially damaged. had been drawn within the Hermann Goering combine, and now "maste enterprise" has, like many other plants, become State enterprise.. Foreign holders Skoda have received assurances that they will receive indemnity full nationalization decided upon, which very likely. The recent exchange French currency for new issue notes dropped ing circulation from $11,800,000,000 $8,000,000,000, roughly one third whole circulation. This exchange has weeded out the notes destroyed looted, those held black marketeers and otherwise improperly acquired. And: now that exchange practically completed, the stage set for capital levy and tax. Used tractor the postwar jeep appears able about everything 4 ? q f 4 | q ries aul | Controlling Quality UALITY control when applied steel castings means that the character and overall prop- erties are consistently and uniformly maintained from casting casting according predetermined standards. The quality level involved, such chemical, metallurgical, soundness and other casting properties, dic- tated the intended service require- ments. Therefore, since design and application steel castings covers wide and diversified uses, the basic specification requirements must ad- justed accordance with satisfactory service performance. The quality level degree perfection each casting design should definitely established *See also ASTM Tentative Standard Radiographic Testing Metal Castings. ASTM Tentative Standard A272-44T, Magnetic Particle Testing and Inspection Steel Castings. IRON AGE, July 19, 1945 that production castings can definitely fixed standards accep- tance. Records show that quality control steel castings for railroad use started many years ago. Regular pro- duction castings were subjected severe overloads and often tested complete destruction. These tests af- forded the engineer and steel foundry- man fundamental information the quality the casting, the effect variable degrees external and internal defects, well valuable design data. With these test results, coupled with actual service records, standards acceptance for railroad steel castings were formed and are now reasonably well understood. Many railroad castings are service today after years satisfactory per- formance, yet these castings may con- tain surface and internal defects varying proportions. These defects amination aus- tenitic steel casting. This example production work subject 100 per cent radiographic examination. are not considered injurious, whereas similar defects highly stressed airplane landing gear, for example, could not permitted. Highest quality steel castings, ap- proaching level perfection, are not only being produced, but have filled large place the war When the highest level casting quality and uniformity desired, the production such parts requires: (1) Strict adherence design prin- ciples for directional solidifica- tion (2) Exacting process controls for manufacture (3) Non-destructive inspection for the standard quality quired. The highest standards for casting quality require more confining and ex- act process controls each operation, since the quality must engineered into the casting and cannot.be de- rived inspection means alone. order assured the high qual- ity desired, certain extra special methods inspection are involved, such radiography, magnetic parti- cle surveys other searching non- destructive tests for hidden discon- tinuities the minutest nature. Naturally, these special operations add appreciably the cost the manu- facturing process, and since economic considerations cannot neglected, the desired quality level must carefully selected with that factor mind. Steel castings, like steel ingots, are subject surface and internal de- fects. These defects must found and removed when required, but un- like billets blooms, must also filled proper repair welding. Satisfactory repair welding can ac- complished with rods capable pro- ducing comparable physical properties after final heat treatment. Failure observe the proper con- trol and design requirements leads defects the following character: Refractory mold sand defects Internal shrinkage Cracks and tears Gas porosity Slag, etc. Inspection for quality several years ago depended largely upon visual ex- amination alone. Other tests for 4 | | 4 ~ ressed ample, ap- are filled gram, asting the es: prin- difica- for re- asting ex- ration, neered qual- special volved, parti- non- liscon- add manu- onomic ed, the refully id. ts, are found un- elding. ac- pro- perties con- ter: ects years ual ex- Castings soundness were destructive and obvi- ously not used production castings. Visual examination still remains effective means quality inspection for commercial grades steel cast- ings; however, when the requirements become more exacting, other methods inspection are employed. Radiographic Tests The most common and presently ac- cepted method non-destructive test- ing radiography (Figs. and 2). Details procedure need not in- cluded here since excellent technical articles are Since 1926, when some the first high pressure cast steel fittings were X-rayed, Gam- ma-ray (radium) techniques, Fig. have been developed for the heavy sections castings involved. The cost films and the operating expense has limited this mode inspection castings. Recently radiog- raphy has been accepted some foundries working tool for the RIGHT 3—Magnetic particle test high pressure, low alloy valve body during the cleanjng process. Surface de- fects, when present, are easily disclosed that would not found normal visual inspection. Operators are checking the internal areas for bore defects. ° ° BELOW inspection pilot casting for high pressure, high temperature steam service, showing pro- cedure used for complete coverage flange with one ex- posure. ° ° ° JOHN JUPPENLATZ Chief Lebanon Steel Foundry, Lebanon, Pa. Although many non-destructive tests are now commercial use for checking the steel castings, high quality something that must built into the product rather than inspected into it. Many inspection checks, while too costly except for the most critical castings, serve prove pilot methods which can maintained production under proper controls. complete exploration all pilot cast- ings before entering production. With such practice pilot castings, the foundry aware shrink- age other defects and may improve methods make design changes overcome these difficulties before pro- duction started. This method quality control has definitely raised the general quality level that may expected from steel since properly controlled repetitive methods should yield equally sound castings without the expense 100 per cent radiographic inspection. Radiographic with proper interpretation are essen- tial and must clearly understood both the foundry and user. Incom- plete knowledge lack workable standards for acceptance can easily defeat the useful purpose this test. The magnetic particle test within the past decade has gained promi- nence inspection method appli- cable magnetic types castings. The American Society for Testing Materials has adopted tentative standard’ for this method technical articles are available the subject. The magnetic particle test primarily limited surface defects only. When the proper flux density applied with subsequent magnetic powder application, surface discon- THE IRON AGE, July 19, ° ° y ai 4—An alloy heat resisting casting being inspected the method. Surface defects, which are cracks this instance, fluoresce with brilliance that would not disclosed visual examination alone. tinuities are quickly indicated buildup the magnetic powder. casting may completely surveyed with lower overall cost than ra- diography. some instances, sensi- tivity the magnetic particle test greater than radiography due the plane the defect, which gener- ally right angles the surface. Small cracks only few thou- sandths inch depth are re- vealed that X-ray would not un- cover. course, defects this na- ture are not normally visible the eye. The magnetic particle test, the other hand, has not proven any particular value disclosing internal defects and therefore does not replace radiography, but rather supplements it. The magnetic particle test applied usually only the 52—THE IRON AGE, July 19, 1945 higher types quality castings, Fig. where service requirements justify the added expense. Fluorescent Method The fluorescent method inspec- tion now being applied both non- magnetic and magnetic types cast materials. This method useful for the determination surface defects only. Internal defects are not dis- closed and therefore the method similar the end result the mag- netic particle test. The equipment required not extensive, nor any part the operation difficult. The casting inspected im- mersed in, sprayed with, pre- pared highly fluorescent, light, water soluble, penetrating oil. After ap- proximately min. soaking period, the oil allowed drain from the casting and the excess oil the sur- face washed away with warm water. The casting permitted dry and then ready for examina- tion darkened room under vio- let-ray light (black lamp), with without the use developing pow- der being dusted over the Any surface defects then appear fluoresce with degree brilliance accordance size and direction (see Fig. 4). Other non-destructive tests such hydrostatic and air pressure tests are employed the steel foundry. Proof tests static loading point just below the yield point, with measure- ment any permanent set, are often made rough finished castings. Supersonic inspection steel cast- ings one the newer methods non-destructive testing, which when further developed and understood should become more widely used means the determination sound- ness, Foreign reports have fre- quently discussed this commercial method test; however, details and its scope use are present lim- ited this country. Jig gaging production castings final inspection used, Fig. means insure adequate stock for machining, including the proper fit the casting into machine tool fixtures. Individual layout procedure, with thorough checking dimen- sional tolerances and wall thickness, always recommended practi¢e pilot sample castings. difficult indicate limits dimensional toler- ance blanket manner but plus treated, high tensile alloy casting being jig-gaged target fixture be- fore shipment. This inspection insures proper and ade- quate finish allow- ances with overall dimensional toler- ances suitable for subsequent produc- tion machining op- erations. | | q if 4 he at , the nina- vio- pow- ection ich are Proof just often stings. cast- ods when rstood used sound- nercial and lim- Fig. stock proper tool cedure, dimen- ckness, ti¢e icult toler- plus minus per cent plus minus 1/16 in. wall thickness the thinner wall sections has been accepted for certain classes steel castings. Close dimensional tolerances are only pos- sible with proper patterns and other auxiliary equipment. Design Precautions Quality steel castings are not de- pendent upon non-destructive testing methods alone. Quality castings be- gin during the early stages design. Close collaboration between the de- signer and the steel foundryman Pattern equipment used for casting. Cope and drag pattern boards are shown with heading and gating carefully planned for cast- ing meet radio- for internal sound- ness. Note the pad- ding required un- der each riser for directional cation. This pad- ding must re- moved during cleaning room op- erations. vitally important, but only too often neglected. Good practical designs which permit the foundryman carefully plan his production meth- ods, with directional possibilities built into the design, are essential for highest quality. not possible, for example, feed metal from thin sections thick sections, since the thinner section freezes early, while the heavy section still molten. Directional solidification in- volves controlling the rate solidifi- cation that freezing will normally occur the thinnest cross-section and gradually progress from that point toward the heaviest cross-section in- volved, which then may adequately fed with hot metal from suitably placed riser. With the tapering and blending wall sections built into the original design, sounder castings with freedom from internal shrinkage can produced. Other methods in- directly controlling directional solidi- fication are available, such the differential thermal gradients result- ing from the planning heading and gating, effective chilling areas padding (tapering) sections which must removed exemplified Fig. Designs with avoided, these often result “hot tears.” Blending streamlin- ing heavy sections into lighter sec- tions always desirable, well the avoidance abrupt angles with inadequate fillets. Proper designs al- ways afford the foundryman the op- portunity adequately feed the cast- ing for freedom internal shrink- age. Good quality castings cannot produced from every design and should not expected. Many com- plex “impossible” steel casting de- signs can best produced with two more castings welded into unit. Process controls actual foundry operations are not only desirable but essential for the highest quality lev- els. Each and every step produc- tion must fully controlled coincide with the previous the sub- sequent operations. Properly made pattern equipment equally important design. From this point on, the quality the casting remains the hands and head the steel foundryman. must carefully plan his methods heading, gating, molding and pour- ing. The most preferable method heading and gating incorporate these essential parts the rough casting the pattern equipment usually mounted integrally board, Fig. This step leaves little the individual molder’s judgment and insures duplication the meth- ods subsequent castings once good practice has been established. has been pointed out that other phases are under process control such molding sands, cores, analysis metal with other metallurgical quali- ties, including pouring rate and tem- perature the molten metal (Fig. 7). After production under known conditions, the pilot casting sub- jected visual and non-destructive examinations some the previ- ously outlined methods. this sample has failed the quality THE IRON AGE, July 19, 1945—53 4 ng in his all | for grade desired, changes are usually made the basic foundry planning requests are made the customer engineering department for ad- design. Once the pilot sample casting has met the quality requirements, production may start and under the same controlled meth- ods, similar quality castings may reasonably expected. After periodic non-destructive test- ing, internal soundness can easily compared with the condition the pilot casting, thereby assuring that production castings are equivalent quality, all other process controls are maintained. previously stated, sand, refractory other blemishes may occur which are usually sur- face origin. These minor defects must located, removed and prop- erly repaired welding with weld- ing rods which produce physical properties comparable those the parent cast metal after final heat treatment. Heat Treating Factors Under process controlled opera- tions, may assumed that sat- isfactorily sound casting produced which dimensionally cor- rect and ready for subsequent heat treatment. Heat treating practice 54—THE IRON AGE, July 19, 1945 should conducted under well con- trolled conditions, uniformly heated and properly constructed fur- naces. Simple annealing treatments are still satisfactory for lower tensile strength requirements, but within the past few years, homogenizing, nor- malizing, quenching and tempering (or any combiriation) trolled conditions has had influ- ential effect the use and perform- ance high tensile steel castings. Cast armor good example where exacting controls for quality must maintained the heat treatment, since ballistic testing each casting not possible. course, after heat treatment, physical properties the castings are checked process control meth- ods such tensile, impact, hardness and other tests. Hardness tests are often taken percentage cast- ings from each heat treatment batch and when required 100 per cent the castings are inspected. Visual final inspection all cast- ings essential. Additional inspec- tion high quality castings may en- tail 100 per cent inspection one more the foregoing non-destruc- tive methods. When stisfactory qual- ity consistently found and main- tained, the frequency testing may substantially reduced. Inspection any method adds burden upon the ultimate cost the casting which turn reflected into the cost. Unnecessary inspection therefore waste manhours and should held minimum. This can accomplished thorough understanding the service require- ment, with specifications properly written for the grade quality needed. Interpretation acceptable stand- ards the casting quality the utmost importance. often, inexperienced inspectors have IS. 7—Checking the pouring tem- perature with optical Mold as. metal has been pro- duced under proc- ess controlled con- ditions. misinterpreted requirements ac- ceptable standards quality which directly resulted the scrapping many useful castings, excessive amount rework and repair. The acceptable standards therefore should carefully considered, clearly de- fined and mutually agreed upon be- fore undertaking any commitment. Quality steel castings can and are being produced large way. Some designs cannot economically made nor can reasonable quality level maintained. Close collaboration the designer and the steel foundry- man, with mutual understanding all requirements, should tend ele- vate the quality steel castings with properly coordinated steel foundry process control methods. > | | | 4 5 a q 4 q \ ; quire- operly juality stand- too have tem- ith pen pro- ac- which cessive The should tly de- be- ent. are Some made evel ion ding ele- with OOLS made plastics can often put into the produc- tion line shorter interval than the case with steel, and the economy attained through the employ- ment plastics especially impres- sive where contours are involved. Re- search done the Lockheed Aircraft Corp., Burbank, Calif., for period two years has resulted some un- usual techniques for handling the plastics, their fabrication with other materials and the incorporation different type plastics the same tool. For purposes this article may convenient discuss first the characteristics and fabricating meth- ods certain plastic materials which have proven time savers Lock- heed and subsequently give the se- quence application methods and materials the construction sam- ple tools. The plastics are treated here the following order: Thermosetting casting resins (such Baker’s casting resin). Phenolic impregnated paper base laminates (Dilecto, Panelyte, Rich- lite). Phenolic impregnated fabric base laminates (Panelyte, Micarta, Pheno- lyte). Colloid treated base lami- nates (Celastic). Glass base laminates Thermoplastic casting materials (Tenite Plastalloy and Ethocel). Baker's Casting Resin Thermosetting casting resins often referred “phenolics” are used making such tools master tool- ing models, formed router blocks, drill jigs, gages, saw jigs, shaper blocks, scribe jigs, and forming dies. Phenol-formaldehyde, resin made the reaction phenol and formaldehyde, basic plastic for thermosetting casting resins that are manufactured under numerous trade names, for example, Baker’s Casting Resin. The synthetic resin obtained Plastic Tooling Procedures The many advantages that may derived from plastics the fabrication such tools formed router blocks, forming dies, hydropress form blocks, scribe jigs, weil jigs for drill, punch and saw, are presented together with sample applications effort provide yardstick which the different types plas- tics materials may measured for individual applications. the first this two-part article the author techniques for handling thermosetting casting resins and laminates having paper, fabric and Fiberglas bases. ° thick liquid state; for casting, acid catalyst and filler are added. The ac- celerated reaction the acid catalyst the resin with the aid heat causes polymerization. The filler, which usually redwood flour as- bestos, makes the casting less expen- ° ° plaster mold made from plaster shells taken model. MARIS Manufacturing Research, Lockheed Aircraft Corp. Burbank, sive and more re- sistant fracture. The plastic cast- ing hard, in- flexible material sufficient strength for its recommended appli- cations. chemically inert, and insoluble. The usual solvents, alcohol, benzine, turpentine, lacquer thinner, EXPERIMENTAL PLASTER SHELL the into ion and This rough tin — 4 A . te al € ~~ THE IRON AGE, July 19, 1945—55 ABOVE 2—Approximate contour the inside mold surface reproduced plywood core. RIGHT 3—Procedure for casting master tooling model. After mold removed, the casting lacquered and checked templates. will not materially affect it; nor will water, oil, gasoline. Its color variable, depending the pigment the resin. The sur- face identical the mold surface. Castings may made conform any shape contour. The meth- ods and formulas vary with the type tool and its intended application. Various fillers react differently the catalyst, altering physical properties the casting, compressive strength, shrinkage, and on. As- bestos flour, asbestos fiber, red- wood flour have been found resist RIGHT 5—Showing two uses being made completed master tooling model. BELOW 4—With water lines and butt lines scribed it, the casting now known master tooling model. 56—THE IRON AGE, July 19, 1945 FOR CONTOUR PHENOLIC POURED BETWEEN FRAME, the acid, and when used fillers with the aid covert product have eliminated after-shrinkage completely. Molds for casting the plastic may made from plaster, wood, metal, glass, cardboard, the plastic itself, combination any the same. Plaster wood have been found most satisfactory because the ease working. The plastic will re- produce the finest detail the mold. cellulose nitrate cellulose ace- tate butyrate lacquer generally used parting medium between the plastic and mold surface except BULKHEAD CONTOUR CHECKED TOOL FIXTURE TAKEN FROM MASTER glass molds where medium needed. thin coat wax placed the lacquer aids the removal the casting from the mold. prepare the plastic for castings, the following general procedure followed: The amount resin, filler, and catalyst carefully calculated. The resin then drained from the container into metal mixing bowl and the filler thoroughly mixed into the resin, electrical motor driven cake mixer being used. The catalyst then added and the whole thor- oughly stirred. PLASTER TAKEN FROM MASTER WHEN FEMALE CONTOUR REQUIRED FOR PATTERNS ETC. * Py 7} | 4 laced the ings, filler, lated. the bowl into riven thor- After thorough stirring, the plastic poured into the mold. Precautions are taken avoid trapping air casting the trapped air results flaws. most molds air vents are provided. The plastic poured into the lowest part the mold forcing the air out works its way up- ward the top. Castings are left stand room temperature from hr. before oven curing, allow air bubbles rise the top surface and permit exothermic heat chemical reaction expended. The castings are baked oven 170 deg. for several hours depending upon the vol- ume the castings and the thick- nesses and materials the mold sec- tions, through which heat must pass penetrate the plastic. general, the castings are removed when they are hard and solid; overnight cure usually sufficient. Insufficient oven heating results weak, brittle, cast- ings; over-long heating does not ap- preciably harm them. The combina- tion heat and acid reaction the catalyst solidifies and hardens the phenolic. The castings are cleaned with de- natured alcohol after removal from molds, and sealed with lacquer sealer. Machining the castings done with wood working tools and machines. Machining the phenolic, involves the same speed, depth cut, that govern work any dense but slightly brittle material. castings where ex- cessive machining contemplated, the use redwood flour filler preferable that asbestos tends dull machine cutting tools. Practically all tools made ther- mosetting casting resin are con- structed with wooden core and faced with approximately %-in. thick layer phenolic the working sur- face the tool. The phenolic when east directly wood, adheres se- curely. Thus, the wood has three- fold purpose: (1) lightens the tool, (2) affords satisfactory founda- tion for thin layer plastic (the thin cross-section plastic cures more rapidly than solid casting) also suitable base which brackets, hold-down fixtures and accessories may attached, and (3) eliminates all initial Illustrated the series sketches (Figs. 1-5) the general sequence operations making plastic master tooling model. full seale plaster model loft the inside outside mold line the skin airframe assembly. Be- cause the plaster model not dimen- sionally stable over long period time, and because dimensionally stable plastic has been developed, duplicate the plaster model made plastic used for permanent reference. Fig. plaster shells are taken from the plaster model. The shells are constructed that they will form into closed mold with only the top open. Care maintained construct- ing the shells insure adequate re- inforcement and eliminate possible CUTAWAY APPLYING 16. base nated laminates are for guides tools such the router block illustrated The rough core positioned the mold and properly fastened avoid possible shifting. Previously prepared thermosetting casting resin poured into the mold, completely sealing the wooden core with phenolic. The cast resin al- lowed stand room temperature for the necessary number hours required permit air the mix rise the top surface and permit exothermic heat from chemical reac- tion expended. SHOWING METHOD PHENOLIC LAMINATE ROUTER BLOCK USING PHENOLIC LAMINATE warping which would distort the con- tour; also wall thicknesses mold are held rather constant fa- cilitate even heat distribution. The inner surface lacquered prevent plastic from adhering. Fig. waterproof plywood core shaped correspond the approximate contour the inside mold surface. Space allowed for plastic, between the core and mold surface. The core constructed laminating sheets plywood and rough sawing the edges simulate the respective contour the mold section. Dowel pins are properly lo- cated hold the core proper posi- tion the mold. Air vents are pro- vided advantageous points. After the preliminary curing partial polymerization has taken place, the mold and casting placed oven and the final set curing takes place. This operation takes sev- eral hours depending the volume the mold (Fig. 3). The mold then removed from the casting after has been taken from the oven. The casting subsequently cleaned, lac- quered and checked for accuracy with templates. Finished castings are not always dimensionally accurate especially they are large and the tolerances small. Molds sometimes lose dimen- sional stability during oven curing the plastic. When this condition exists the plastic model may THE IRON AGE, July 19, we 7 wae \ q ROUTED PART splined templates using scrapers and sanders providing the model oversized; additional resin may added and cured with heat lamps the casting undersized. Fig. water lines, butt lines, and reference lines are scribed and known master tooling model. The completed plastic master tooling model demonstrating typical methods obtaining die contours, and method obtaining contour check fixtures for checking production tool- ing illustrated Fig. 7—Formed router block constructed types plastics, wood, plywood, Masonite, Kirksite and steel ° ° ° 9—A portable showing process for embed- ding hinges, bush- ings, and pins Ce- lastic layers. this illustration the lami- nate has been used for the nest and drill plate. Parts designated ters the illustra- tion are follows: A—Celastic sheets, B—drill bushing, —cellophane, embedded hinge, part, bushing pins. ° ° ° colored for visual aid. Reference lines were transferred through the operations from the plaster model, the plaster shells and finally the plastic casting. The casting at- tached suitable steel base. After lacquering, the tool complete, and 58—THE IRON AGE, July 19, 1945 Furthermore, the master affords permanent dimensionally stable model that can used establish contours checking gage, tool contour tem- plates, cast patterns, blue blocks and fixtures, and establish trim lines and hole locations jigs. Laminates the phenolic impreg- nated paper base type are manufac- tured under several trade names such as, Dilecto, Panelyte, Richlite, etc. The tools that are made of, par- tially made these laminates, are: Hydropress and hand form block, such are used form flanges and jog- gles and are free double contours; drill jigs such junction boxes; router blocks—the laminate being used guide bases for pin routers. Best applications are for single plane contoured tools and for structural combination with other materials. The processes used making the laminated phenolic plastics are very similar; basically they are: (1) The manufacture the thermosetting synthetic resin, (2) the impregnation the paper and (3) the pressing and the impregnated sheet the use heat and extremely high pressure. When the impregnated sheet sub- jected heat and pressure the sev- eral individual layers paper and phenolic are compressed and cured into dense homogeneous mass. The laminates are manufactured wide variety grades, depending the paper base and the resin con- tent, and the reaction the ingredi- ents. Each specific grade intended for specific use and formulated possess definite characteristics. Some grades are primarily intended for electrical insulation applications and possess very good insulating qualities while other grades are made serve mechanical capacities, and are strong and tough. The grades de- signed for mechanical applications are employed for tooling Lockheed. The finished surfaces these lami- nates are attractive, they are supplied with dull, semi-gloss, and ished finish. The colors are black, and natural which varies from light brown dark brown. Standard sheet sizes are: 38, 43, thicknesses from 0.010 2.0 in. in- clusive.* The laminates rigid, materials having relatively high tensile strength (8000 per sq. in), compressive strength (3400 Ib. per sq. in.) and flexural strength (16,- 000 per sq. in.).* They are di- mensionally stable. For most prac- tical purposes they may consid- ered chemically inert, insoluble, and infusible. The usual solvents such alcohol, benzine, turpentine, lac- quer thinner, have effect them nor does water, oil, gasoline. The light weight the laminated plastics (approx. that alumi- num) makes their application tool- Dilecto Grade Quoted. | | | 4 4 2 q . ° ° ° | | ‘4 — } ifac- such tc. par- are: such jog- tural the very The tting ation and high sev- cured nding con- ended istics. ended ations lating made and de- are lami- pplied and light 43, and in. in- hard, high sq. (16,- di- prac- oluble, such lac- ect alumi- tool- ing preferable that metals, when the performance satisfactory. Machining qualities the plastics are very good. They can sheared, sawed, shaved, punched, milled, turn- ed, drilled, reamed, threaded, sanded and stamped. machining, practi- cally the same rules apply ma- chining brass. Highest possible speeds and the use carbide tipped tools are recommended the manufactur- ers. Fabric Base Laminates Phenolic impregnated fabric based laminates are manufactured under trade names, among them Panelyte, Micarta, and Phenolite. These lami- nated sheets are used conjunction with other materials make tools such as, horizontal router blocks, the fabric based laminate being used the guide, shown the tool illustrated Fig. They are also used bases for attached tool accessories, for example, hold-down clamps. The fab- ric base has excellent holding quali- ties for screws, pins, etc. The processes used making these laminates are basically the same those used making the paper base laminates except that fabric used place paper. Like the paper base laminates they are manufactured wide variety grades depending the base material used, the resin con- tent and the reaction the ingredi- ents. The grades intended for me- chanical applications are the ones re- ferred this article. The laminates used Lockheed are made high grade, heavy weave, cotton fabric base, and are strong, tough and abrasive resistant. They are obtainable sheet sizes thicknesses from 0.015 in. and including 2.0 in. The finished surfaces these lami- nates are semi-glossy and are usually natural color which light brown. Like the paper base lami- nates, for most practical purposes, they may considered chemically inert, insoluble, and infusible. The usual solvents such alcohol, ben- zine, turpentine, lacquer thinner, have effect it; nor does water, oil, gasoline. The base lami- nates are hard, rigid materials, pos- sessing greater strengths than the base. Tests Panelyte 900 (flat with grain) give 12,200 lb. per in. tensile strength, 40,000 Ib. per sq. in. compressive strength and 20,300 Ib. per sq. in. flexural strength. They are dimensionally stable and light weight, approxi- mately the same the paper base laminates that aluminum). This factor makes their application PLASTER REMOVE PART BASE SPR APPLY LAVER AND POUR PLASTER FORM BACKING... PLASTER CELLOPHANE 200 LAY PART REQUIRED DEPTH.. LAY CELLOPHANE OVER CELASTIC.. APPLY PRESSURE WITH Fig. forming drill plate Celastic (fabric base colloid treated tooling desirable where applicable. Machining qualities the plastic laminates are good. They may sheared, sawed, shaved, punched, milled, turned, drilled, reamed, tap- ped, threaded, sanded and stamped. machining, practically the same rules apply brass. Highest pos- THE IRON AGE, July 19, 1945—59 OPERATIONS woo PART BASE . 7 A « . j S CELLOPHANE —_ FRILL q j 10—Formed router block with Celastic hold-down plate. Formed sheet metal part nested and held position shown, and excess flange trimmed. sible speeds and the use carbide tipped tools are recommended the manufacturers. The fabric base laminate recom- mended guides for router blocks (Fig. where the contour singu- lar, because its resistance abra- sive wear and its heat forming quali- ties. may formed with radius times its thickness heating When has cooled will retain the formed shape. Thin sheets, about in. thick, are formed and glued to- gether with Phenoglue. The thin sheets facilitate forming and the laminate builds strength. not recommended for multiple contours compound curves due the fact that heavy equipment would required form the material. recom- mended that Celastic, Fiberglas resin-impregnated laminates con- sidered these more difficult appli- cations. general, the fabric based lami- nates may used place the paper based laminates, where greater strength required and/or where simple forming necessary. Fig. formed router block, combination tool used pin router and horizontal router, and con- structed wood, thermosetting cast- ing resin, Celastic, Panelyte, Mason- ite, plywood, rolled Kirksite and steel. Heat forming grade Panelyte was formed and attached cylindrical side act guide for horizontal router bit. Dilecto furnished guide for the horizontal router bit the other side. Dilecto being cheaper, was used because forming was neces- sary. The bottom made Mason- ite with Kirksite embedded for guid- ing the pin router. Masonite will chip when used for guides, while the other hand Dilecto could have been used eliminating the necessity in- serting the Kirksite critical wear- ing areas. Celastic backed with ma- hogany comprises the hold-down. ° part side the Celas- tic hold-down plate showing how pre- cisely contours and have been incorporated the plate. Since this tool was made, has been discovered that Fiberglas laminate adapts itself this type equally well and less expensive fabricate. Here featured the combinations plastics obtain light, quick, in- expensive tools. These plastics made possible the fabrication tool, which when used conjunction with the routers, opened new and faster method trimming the part shown. Previously the part was hand trim- med with overpress template used pattern. The part now trim- med complete this one tool. Celastic Celastic the trade name col- loid treated fabric; the composition cotton flannel impregnated with mixture Pyroxlin and fire re- tardant. Pyroxylin trade name cellulose nitrate solvent such ether. The treated fabric semi-stiff like and resembles heavy blotter paper appearance. When solvent applied, such ethylacetate, any Pyroxlin solvent, this fabric becomes soft and pliable, and may shaped quickly and eas- min., but preferably overnight, will gain rigidity the Pyroxylin solvents are used. The solvent evaporates leav- ing the Celastic the formed shape. Using special covert solvent devel- oped Lockheed will gain rigidity deg. The latter solvent polymer- izes rather than evaporating thus adding strength the Celastic. (Also, shrinkage, which occurs when other solvents are used, practically elimi- nated. This factor paramount importance building certain types tools, for example, drill plates.) Celastic adheres any material in- cluding metal. Cellophane and/or covert lacquer are used parting mediums, these materials stick Celastic but not adhere other materials. Laminating requires the simple operations submerging the sheets the solvent and laying successive sheets one upon another until the de- sired thickness obtained. Metal bushings, hinges, etc., may fitted their respective positions during the operation. Slight pressure, convenient means, are applied and then the lami- nate baked polymerize the sol- vent previously mentioned. When cured, impossible delaminate and edges not chip. The material hard and rigid, light weight (one-seventh the weight steel) and has very good strength qualities. The co-efficient thermal | — 4 60—THE IRON AGE, July 19, 1945 other sheets essive de- Metal fitted enient sol- When ninate rigid, weight rength expansion nearly parallels that alu- minum. Initial shrinkage and after- shrinkage are practically nil. Oil and water have effect it, but the common solvents do. Virgin sheet Celastic may cut like cloth with or- dinary scissors tin snips. Lami- nated Celastic has very good machin- ing qualities, may sawed, drilled, filed, tapped, and lightly sanded. Operations performed making drill plate are explained Fig. These operations are basic and the operations are simiiar for all appli- cations which are date, hold-down plates and drill plates cages. Fig. shows portable drill jig with hinges, bushings and pins embedded Celastic layers. use the formed router block, Fig. 10. consists wooden nest block with face, Celastic hold-down plate, plywood base, Dilecto bottom guide plate, steel and maple wood ac- The Celastic hold-down plate (Fig. 11) weighs only one-sev- enth much steel hold-down the same size. follows the cont