Evaporators can be made of stainless steel or aluminium. For stainless steel, repairs are made either by brazing or welding with tungsten ARC-inert gas systems. For aluminium evaporators, repairs can be done by soldering, brazing or welding, but the use of epoxy is common. Use the following guidelines to eliminate leakages in each type:
Stainless Steel
Locate the leak.
Removing refrigerant using the recovery/recycling of the device.
Clean the metal around the leakage. Nitrogen purging (a very low pressure) when brazing or welding.
Polish welding or clear brazed seam. Leak testing.
Aluminium
Locate the leak.
Removing refrigerant using the recovery/recycling of the device.
Clean around the leakage. The oxide surface hard and should be deleted. Repair immediately after cleaning as oxide stuface forms quickly (Sand, file, and then with clear epoxy cleaner.) If the leak big hole, use a clean, small screw or metal plug to fill most of the opening.
Mix the epoxy resin and catalyst.
Used when mixed with a spatula. (Be sure that there is a positive pressure in the system. The system must be open to the situation in some other opening.) Wait at least an hour for quenching. Sand patch on a smooth surface. Leak testing. If the system still leak repair joints, remove epoxy by filing and/or grinding. Then install the new patch. Aluminum foil can be used with epoxy cement to strengthen the joints. It can also improve the appearance of repair. Another method repair of thermal handsets and apply paste mix (or stick) special epoxy and resin.
Avoid soldering of aluminum tubes as it overheats too easily. Too many tubes will annealing (softened), the weakening of the tube wall. Aluminum tubing, as a rule, alloy 3003. However, 5005 and 1100 alloy.
Aluminium solder containing 92% to 100% of zinc is used. The melting temperature of 700F SOOT (370C to 430 C). Do not use RSS. Aluminium can also be welded. Use inert gas tungsten arc welding system (sometimes called argon arc welding TIG or...
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