Document Ex2Op1RzkMvD02qxvgn36JEpR

LAINTZFF'S EXHIBIT TECHNICAL BULLETIN GYPSUM J OATH: March 1972 ' BULLETIN NO- 5702-A WALIBOARD ACCESSORIES - JOINT TREATMENT PRODUCTS . JOS PROBLEMS AND REMEDIES Successful joint.treatment of gypsum wellboard surfaces requires particular attention to proper mixing instructions, weattier conditions, and job application techniques. MIXING INSTRUCTIONS When the recommended mixing procedure for dry powder compounds Is not followed, potential problems which may result include: ' 1. Poor Bond This may occur because of incomplete solution of binders or nonuniform dispersion of the powder. 2. Mealiness The condition described os mealiness often is the result of thinning out or letting down ofter mixing. This can be avoided by allowing the natural thinning which occurs when the powder dissolves to take place before final dilution to working consistency. 3. Graininess This is often the result of improper dispersion of the powder throughout the mixture. Mixing the material at o thick consistency initially will force a more complete blending of material. A thin mix does not provide adequate shear forces to break up lumps rapidly and properly disperse the lumped materials. 4. Dry lumps Often dry lumps, particularly in the Finishing Compound, ore the result of powder which has not been mixed thoroughly. The above mixing technique will minimize this problem. 5. Pin Holes Very frequently, pin holes in the Finishing Compound are the result of spotty or erratic dispersion of the powder in the wet paste. 6. Poor Workability This is an oil-encompassing term which is hard to define. However, it is not uncommon to blame workability variations on the material when octually the material was poorly mixed. Proper mixing procedures will assure maximum workability characteristics. -- - 7. Short Open Time Excessive thinning of the compounds can affect the open time. This con be alievioted by proper mixing procedure, . 8. Shrinkage Shrinkage is exaggerated with a thin mix, or by slaw drying conditions. KAISER GYPSUM CO.. INC..300 LAKESIOE ORIVE-O AKL AND. CAL. 04604 ON V I V J 'ibOifttCAl. JUUfTIN S702-A March 1972 Poge 2 JOB PROBLEMS AND REMEDIE5 F.ven with the um of properly mixed powder compound* and factory pre-mixed compound*. Job problem* eonoriie Are ro extremes In weather condition* and job-application techniques. Among the more common problems, with probable causes and suggested remedies ar preventions, are the following: .' . Suggested Remedy ar Prevention Problem . .1 Wet paste lumps Probable Causes Ory Powder Compounds Pre-Mix Compounds Poste frozen in storage. Thawing of paste before use does rot eliminate lumps. Incomplete mixing.. Remix botch; mixing should be done by sifting powder into wafer) stirring vigorously and remixing offer 30 minutes; recommend mechanical mixing. Do not allow compound to freeze in storage. Mix thoroughly before use to remove lumps. 2. Poste breaking down or watering down. ` Too much mixing water; hot weather. 3. In cold weather, pasta hard and `solid''. - *** Paste frozen In hot weather, paste puffy and poor working. Thinning oufr of high tmprorufft. ' Add more powder and mix . thoroughly. Protect from hot weather by using cool mixing water and sheltering from sun. Do not use; mix fresh paste and keep paste in protected room obov. 35* F; use 70 F water for mixing; do not use hot water for mixing. Use cool mixing water and keep paste out of sun; keep small amount of water on top of paste in bucket, paste temperature should not ex ceed 9CP F. Do not store overnight in hot weofher. Protect from hot weather by using cool added mixing .water and sheltering from sun. Remix before us*. Do not allow compound to freeze in storage. Thaw by storage in o warm area before use; do not hoot past* above 90P F. Remix thoroughly after thawing to remove wet past* lumps. 5. Souring of paste ' Hot waather; paste stands in buckets too long; dirty buckets. Do not use sour poste; mix fresh material with cool water in dean buckets; keep out of sun. Do not use sour pasta; after opening container, use material within 7 days; keep container covered when not in use. 6. 7. 8. Cheeking in heavy fill application Voidsjpr air pockets Grit Compound ragging Slow drying conditions of low temperature and high humidity, past drying eonfions of high temperature and low humidity. Whipping air into paste during mixing. Dry material scraped off sides of bucket ar pan; dirt from floor. Hot weather; paste too stiff; paste too thin. All Compounds Maintain a minimum of F. temperature in house during application and drying of material. (iie Pre-Mix in hot, dry weather. Adjust mixer to keep mixer blades, below lap of paste; ran mixer slowly. Clean up buckets; do not salvage droppings from floor. Adjust method of application to ovoid ragging; finish rapidly. Use proper mixing. Screen openings during hot, windy weather. -1# TECHNICAL SLILLETIN 5702-A - March 1972 Page 3 JOS PROBLEMS AND REMEDIES--Contd. Problem .10 Short on coverage Probabl* Causs Past* applied relatively thick on joints; extra dropping on floor. Suggested Remedy or Prevention All Compounds Check board alignment far deep fills an joints; check lineal feet of joints treated; check width of space between boards. Check amount of metal trim. II.. Blister* under tap* Not enough joint compound under tape to bond; tape smooth, slick, anchor not chamfered. Cut out blisters and apply joint compound; prevent blisters by checking board align ment and favoring high spots where the braadknif* forces out all the paste on wiping down. Check tape far proper chamfer. 12. Edge cracks and shacks Fast drying of'joint compound; excessive thickness of joint compound under tape; shrinkage of tape; paste too old and weak; very slow drying; joint compound ' wiped out from under tap* edge. Apply fine line of latex glue, such os "Elmers" or "Wilhotd" along the edge crack and caver with finish compound. Cut out blisters and apply joint compound. Use Pr*-Mix for taping and finishing in hot, dry weather. 13. Top* not bonding to wallboard .14 Rusty nailhoods Joint compound not dry; insufficient joint compound under tape. ' Allow joint compound to dry. Moisture content of joints should be same as the wallboard. If there is still no bond, remove tap* and rttape with fresh top*. Maintain a minimum'temperature of 55 F. in house during application and drying of material. Use of uncoated nails; railheads tasty before spotting; dirty mixing water; very slow drying. Carefully spot railheads with on emulsion sealer before application of joint compound or finish compound. ` 15. Poor bond with m*tal earner bad .16 Shadowing of joint through paint .17 Beading Oil film on metal comer bead; extreme daily job temperature variation, causing excessive metal expansion and contraction. Remove dried joint compound. Remove oil film from metal. Reapply with fresh compound. Difference in suction between joint and paper surface af wallboard. Joint rat dry before paint application. In a small area, try second coat of paint; or seal the surface and repaint. Provide proper heat and ventilorion. Maintain a minimum of 5^ F. in house and allow - sufficient drying time before decorating. Changes in temperatures and humidity during application; wallboard with cupped edges; poor framing; improper railing; poor bond betwean joint com pound and tope. . Maintain a minimum of 55 F. temperature in house during application; allow sufficient time for joint compound to dry before finishing. To repair, sand surface smooth and reapply finish coot. IS. Nailh*ad dimpling ?.1 Cupping and wrinkling of tape an wipedawn 20. Exssssiv* shrinkage - Swelling of lumber, forcing wallboard against railhead. Stiff and hard tape due to normal moisture removed from paper. Excessively slow drying of compound. Inadequate drying time between finishing coats. Respot noils with joint compound* Protect tape from excessive heat and drying; stare in a cool area, free from dampness. Maintain a minimum of 55 F. in house during taping and tapping application* Provide adequate ventilation. Allow each coot ta dry before subsequent treatment. * f