A/c Tubing

Unregistered

i need to fix some tubing connection that were soldered . can i silver solder over them with out removing or replacing them . working close to evap coil and cant shorten tube anymore . any ideas ?

HVAC Doc

Make sure there is no refrigerant in the system. Clean the connections thoroughly as I assume when you say solder you are talking they were soft soldered (like plumbing). Make sure that when you braze in the new connections it flows evenly around the joints. It may even require cutting out the old joint and using a new coupling to attach the two pieces. Evacuate the system and it probably would not be a bad idea to install a filter drier into the system as well while you have it open.

Unregistered

so the silver solder will stick to the soft solder . i wasnt sure if it would .

i hate going behind someones elses work !

thanks

HVAC Doc

Actually if you clean the connection good, by the time you hit it with the oxy/acet torch and get the joint hot enough for stick braze, there won't be much (if any) of the soft solder left.

Unregistered

be verry carefull, a butane torch will not reach the desired temp to braze silver solder you will need oxy. accet. torch kit to do this. plus if the other fittings was soft soldered in the heat from silver soldering will travel through the copper and if the other fittings are close there is a good chance you will melt the soft solder and have a even bigger problem. The best thing to do is if all the joints are soft soldered then cut them out and use silver solder on them. and be sure to pressure test the system afterwards for leaks then make sure you insatll a liquid line filter drier on the system and pull a good vaccume.

Unregistered

Yeah, by that time all of the soft solder will be inside the system due to capillary action ... where it should not be.

To repair a leak:

1. pump down refrigerant into condenser.

2. cut out problem area on copper lines

3. install new fittings and solder in (using proper soldering technique)

4. also solder in a new liquid-line filter-drier.

5. evacuate system to proper level (using proper evacuation technique)

6. leak check

7. charge to manufacturer's specifications (using proper charging technique)

8. leak check

Thank you and have a nice day.

Unregistered

Depends on your skills with a torch. If you are a novice and not a professional and used to making good clean joints, I wouldn't recommend attempting it like HDoc said. But if you have many years of brazing under your belt and know how to control your torch, heat, and flame direction a pro can have the new joint brazed before any of the others get soft.