BRAZING WORKSHOP Individuals who desire further training in correct soldering, brazing, and welding procedures should consider attending The Harris Products Group brazing workshop. This two-day, comprehensive course conducted by The Harris Products Group Technical Staff covers fundamentals of torch brazing. The course combines classroom discussion with hands-on metal joining experience including basic metallurgy, base metals, filler metals, equipment, technique, and safety.
TABLE OF CONTENTS The Harris Products Group Workshop . . . . . . . . . . . . . . . . . . . . . 1 PROCEDURES AND TECHNICAL INFORMATION Procedure For Brazing Pipe And Tube . . . . . . . . . . . . . . . . . 5-10 Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-12 Repair of Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Estimating Amounts of Brazing Alloy/Joint . . . . . . . . . . . . . . . .
FORWARD Brazing is a metal joining process utilizing a filler metal which melts above 840º F and below the melting point of the base metals. The filler metal is drawn into the joint by capillary attraction producing a sound, leak-proof connection. These sentences briefly describe a process which is an integral part of manufacturing, installing, and repairing refrigeration and air conditioning systems.
Procedures and Technical Information www.harrisproductsgroup.
PROCEDURES FOR BRAZING PIPE AND TUBING Cut pipe square. Cut to the exact length required using a tube cutter or hacksaw. If a hacksaw is used, a sawing fixture should also be used to ensure square cuts. Remove all inside and outside burrs with a reamer, file, or other sharp edge scraping tool. If tube is out of round, it should be brought to true dimension and roundness with a sizing tool. Remove inside burr. Remove outside burr. Clean tube end and inside surface of fitting.
Clean outside of copper tubing. Select Brazing Alloy. Refer to the chart 12 on pg.30-31 for recommended brazing Filler Metal selection. When brazing copper to copper, alloys such as Dynaflow, StaySilv 5, or Stay-Silv 15 are recommended. These alloys contain phosphorus and are self- fluxing on copper. When brazing brass or bronze fittings, Stay-Silv white flux is required with these alloys.
Assemble tube and fittings. Insert the fluxed tube end into the fitting. Maintain support to ensure the proper alignment until the brazing alloy solidifies. After brazing maintain support for a few seconds (or more) depending upon the size of the joint area. The assembly is now ready to braze, using brazing alloy in rod, wire, or in coil form manually fed into the joint. Assemble tube & fitting. Adjust torch flame. Oxygen/Acetylene.
Brazing with air/ acetylene torches is a popular alternative to oxygen mixed fuel gas. The fuel gas flow aspirates air into a mixer that contains an internal vane that spins the gas to improve combustion and increase flame temperature. If the tank has a delivery pressure gauge set the delivery pressure at 14-15 psi. If the tank has only a contents gauge delivery pressure is preset at the factory so open the regulator adjusting screw all the way by turning it clockwise until it “bottoms”.
Do not overheat the joint. Keep fitting and tubing uniformly heated. Feed alloy into joint...the torch flame will help melt the alloy, but the heat of the joint must flow the alloy into capillary. When making vertical alloy-up joints heat the tube first, then apply heat to the fitting. It is important to bring both pieces up to temperature evenly. Keep the flame directed toward the fitting.
In spite of the suggestions and cautions we have noted, the art of brazing is relatively simple, and the rules are common sense rules. Occasionally, however, things do go wrong, and the brazing process fails to do its job satisfactorily. The check lists below have been prepared to assist in such instances. They are intended to give practical tips on what to try and what to look for. If brazing alloy does not flow into the joint, even though it melts and forms a fillet 1.
If the filler metal cracks after it solidifies 1. When brazing dissimilar metals, the different coefficient of expansion may put the filler metal in tension just below the liquidus temperature during cooling. This sometimes occurs in a copper-into-steel joint. The copper expand and contracts at a greater rate than the steel. Brazing alloys are stronger in compression, so a steel-into-copper assembly would help alleviate the problem. 2.
1. Locate the tube diameter to be joined and the wire size to be used. Where the row and the column intersect is the approximate length (in inches) of alloy required per joint. 2. Multiply the length of the alloy needed per joint by the total number of joints. 3. To convert the total length to pounds or troy ounces, divide by the inches of alloy/lb in row A or the inches of alloy/troy oz in row B. Chart 1 Estimating Brazing Alloy Amounts Tip Size Estimated Acetylene Use(C.F.H.
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SPECIFICATIONS www.harrisproductsgroup.
PHOS-COPPER BRAZING ALLOYS Phos/copper and silver/phos/copper alloys are used to braze copper to copper and copper to brass. The phosphorus content in these alloys makes them self-fluxing on copper. When brazing brass or copper to brass, use Stay-Silv white brazing flux. These alloys are not recommended for brazing steel or other ferrous metals.
Blockade® Brazing Alloys. Silicon brazing alloys offer significant advantages over phos/copper and silver/phos/copper (BCuP) brazing alloys and present important differences in the brazing of copper and its alloys.
Safety-Silv®40 Ductile, free-flowing alloy offers economy, good penetration into tight connections, and medium temperature. Silver to light yellow color as in polished brass. Safety-Silv®45 Excellent general purpose non-toxic brazing alloy. Often specified in governmental use. Good ductility and capillary flow. Color is silver to light yellow as in polished brass. Safety-Silv®45T Performs like a 45% silver, cadmium-bearing alloy. Lower melting temperature than Safety-Silv 45.
Stay-Brite silver bearing solders were introduced to the air conditioning industry more than 40 years ago. Today Stay-Brite is the most used of all solders. Extremely versatile, Stay-Brite silver-bearing solders are widely used throughout the industry as a better-than-brazing method in many situations. The important advantage of Stay-Brite solders is the greater strength of the overall component.
LEAD-FREE SOLDER DEVELOPED SPECIFICALLY FOR POTABLE WATER SYSTEMS Bridgit® Meets ASTM B32. A patented, high-performance, lead-free solder developed by The Harris Products Group in response to the Federal ban on the use of lead solders in drinking water systems. The lead-free solder is specially formulated to fill both tight and loose-fitting connections.
Tin-lead 50/50, 40/60, 60/40 meet ASTM B32. With some exceptions, the tin-lead solders can be used to solder copper and most copper alloys, lead, high-nickel alloys, and steel. Tin-lead solders are not recommended in high stress or vibration joints in the cooling industry due to lack of sufficient elongation properties. Heat sources include soldering guns, irons, and torch applications. Tin-antimony 95/5 meets ASTM B32.
ALUMINUM ALLOYS Alcor aluminum alloy with non-corrosive flux inside the wire; no external flux required. Very good fluidity with good capillary attraction. Post-braze cleaning unnecessary. Better than tin-zinc and aluminum silicon alloys for aluminum coil repair. ® Alsolder 500® forms excellent corrosion-resistant joints on the tough-to-solder aluminum alloys. Joints all solderable aluminum alloys to each other and to dissimilar metals, both ferrous and non-ferrous.
Safety-Silv® 45 3/32”x 18” Mini Pak 45518LMPOP 45% Ag 30% Cu 25% Zn Safety-Silv® 56 1/16” x 18” Mini Pak 56318LMPOP 56KPOP Safety-Silv® 56 1/16 Brazing Kit Safety-Silv® 56 56F318MPOP 1/16” x 18” Flux Coated Description Part # 56% Ag 22% Cu 17% Zn 5% Sn Chemical Composition AWS A5.8 BAg-5 NSF 51 1145°F 618°C 1205°F 652°C For ferrous and nonferrous alloys. Often used to braze stainless steel for food service. Typical Application General purpose filler for steel and copper alloys.
www.harrisproductsgroup.com Stay-Brite ® Solder Kit with Flux SBSKPOP 50/50 1/8” 8oz Spool 60/40 1/8” 8oz Spool 60/40 1/16” 8oz Spool 505061/2POP 60R61/2POP 60R31/2POP Part # 430°F 221°C ---------- 430°F 221°F Production packs available. Contact customer service.
Bridgit® High Temperature Paste Flux 4 oz ----------- Meets Commercial Spec. A-A-51145C Stay-Clean® Paste Flux 4 oz SCF4POP BRPF4POP Below 1600°F Meets Federal Spec. OF499,Type B AWS A5.31 Class FB3A AMS 3410 Stay-Silv ® White Brazing Flux 6.5 oz SSWF7POP Below 800°F Below 700°F Active Temperature Specification Description Typical Application Designed for lead-free solders and well suited for use in larger connections where prolonged heating will cause other fluxes to burn.
www.harrisproductsgroup.com Specifications AWS A5.8 BCuP-5 AWS A5.8 BCuP-3 ------------ AWS A5.8 BCuP-2 Chemical Composition 15% Ag 5% P 80% Cu 5% Ag 6% P 89% Cu 6% Ag 6% P 88% Cu 7.2% P 92.8% Cu Description Stay-Silv® 15 .050”x 1/8” Mini Pak Stay-Silv® 5 .050” x1/8” Mini Pak Dynaflow® Mini Pak Harris 0 Mini Pak 1520FMPOP 5620FMPOP D620FMPOP 0620FMPOP Production packs available. Contact customer service.
Stay-Brite® Solder 1/8”x 8 oz Spool 95/5 1/8”x 8oz Spool SB61/2POP 95561/2POP 430°F 221°C 452°F 233°C ASTM B32 Sn96 NSF 51• J-STD-006 Sn96Ag04A ASTM B32 • Sb5 J-STD-006 Sn95Sb05A 4% Ag 96% Sn 95% Sn 5% Sb ------ BRGT61/2POP 460°F 238°C ASTM B32 HB • NSF to ANSI NSF61 Conforms to 1986 Safe Drinking Act Bridgit ® Solder 1/8” 8 oz Spool Solidus Specifications Description Part # Production packs available. Contact customer service.
Chart 12 Filler Metals FILLER METALS Copper or Brass To Copper or Brass Copper or Brass To Steel or Stainless Steel or Stainless To Steel or Stainless Steel or Stainless To Carbides Aluminum To Aluminum (1) Aluminum To Copper Or Brass (2)* Aluminum To Steel Or Stainless (2)* (1) Can be directly brazed or soldered. * Aluminum dissimilar metal joints may subject to galvanic corrosion.
PRODUCTS & SPECIFICATIONS Stay-Clean® Soldering Flux Harris Powertorch® Air - Fuel Equipment Bridgit® Water Soluble Paste Flux Harris Powertorch® Air - Fuel Equipment No flux required for copper-to-copper joints with the phosphorus-bearing filler metals. For brass and other alloys of copper, use Stay-Silv® White Brazing Flux.
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NOTES & COMMENTS NOTES www.harrisproductsgroup.
Use The Harris Products Group Brazing, and Soldering Products For Best Connections. Blockade®, Dynaflow® Brazing Alloy, Stay-Brite® Silver Solder, BRIDGIT® Lead Free Solder, Safety-Silv® Silver Solders, Harris Phos Coppers, Stay-Clean® Soldering Flux, Stay-Silv® Brazing Flux are registered trademarks of The Harris Products Group. A Lincoln Electric Company The Harris Products Group 4501 Quality Place Mason, OH 45040-1971 513-754-2000 www.harrisproductsgroup.