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Heater core soldering

Discussion in 'Early CJ5 and CJ6 Tech' started by piffey263, Dec 11, 2011.

  1. piffey263

    piffey263 Active Member

    Im at the point where I get to try soldering my heater core (I want my heater)

    From my understanding I can use a propane torch.
    And I heat up the core tell it separates

    Then clean with a wire brush and sand paper

    Do I clean it with anything else (core was flushed with water couple times)

    What type of solder and flux should I use?

    And any tips?
     
    piffey263, Dec 11, 2011
    #1
  2. nickmil

    nickmil In mothballs.

    acid core solder works well after thorough cleaning and drying. Lead solder if you can find it with an acid flux works ok too.
     
    nickmil, Dec 11, 2011
    #2
  3. Admiral Cray

    Admiral Cray I want to do this again.. Staff Member

    Heat is going to be the biggest problem. I solder a lot of copper pipes as a contractor and silver soldered as jeweler in college (Masters degree minor).

    With a propane torch, the core will suck up the heat fast. An acetylene torch would be a lot better to control the heat. Too much heat is bad too. You will need a good flux, use a little more than you think you should. You can't be too clean. The best way to heat up the area you are soldering is to paint with the flame, like a paint brush, the heat on. Also make sure the whole core is heated up too so you don't have any cold joints.

    If you can pickle the core in as mild sulfuric acid (5-10%), slightly heated the core will look like new and be clean.

    Soldering is a skill like welding. If you can, first practice on a test piece so you can get the hang of it. :beer:

    Or take the core to a radiator shop. :)
     
    Admiral Cray, Dec 11, 2011
    #3
  4. piffey263

    piffey263 Active Member

    Good thing I'm good at gas welding

    I think I will use a small tip then or attachment on the propane
     
    piffey263, Dec 12, 2011
    #4
  5. piffey263

    piffey263 Active Member

    Cap-n-Cray what do you mean by pickling the core? Home repair stores should sell sulfuric acid right? I know they sell flux and acid flux
     
    piffey263, Dec 12, 2011
    #5
  6. BC3Jeep

    BC3Jeep Electric Bill

    I would X2 on taking it to a radiator shop... leave the professional work to the professionals....... the $$$$ will be well spent with a HIGH quality result.
     
    BC3Jeep, Dec 12, 2011
    #6
  7. Patrick

    Patrick Super Moderator Staff Member

    There's no reason a radiator or heater core can't be soldered at home. I've been soldering them since I was about 16.

    I've never soldered a core with acetylene; always used propane or butane. with the right torch/ tip it's no problem.

    Like Nick says, use acid core solder, and clean, clean, clean..
     
    Patrick, Dec 12, 2011
    #7
  8. Admiral Cray

    Admiral Cray I want to do this again.. Staff Member

    This what I use for pickling: Sparex No. 2

    I have a solution of stuff in a copper pot. I heat it, but not boiling. It works faster when heated. You would need to submerge the core in some kind of tank that could be heated. I think radiator shops have large vats of some kind of pickling solution for radiators. Does a good job of cleaning oxide off, which makes the soldering easier.

    Most plumbers use air/acetylene torches and air/acetylene is used in silver and gold soldering jewelry. The torch temp is higher than propane or butane. Some silver solder flows at 1100* and up to the melting point of silver.

    Cary
     
    Admiral Cray, Dec 12, 2011
    #8
  9. Patrick

    Patrick Super Moderator Staff Member

    OK. I guess I don't know what radiator repair shops use for sure.
     
    Patrick, Dec 12, 2011
    #9
  10. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    "Muriatic" Acid (30% HydroChloric) works extremely well for cleaning brass and copper prior to soldering. Sold as a masonry cleaner in hardware stores.

    I've sometimes used a torch in one hand for general preheat of a core, then a high powered electric solder gun in the other hand to hit the exact spot. This gives enough heat, but with better control to avoid melting surrounding joints.
     
    PeteL, Dec 12, 2011
    #10
  11. piffey263

    piffey263 Active Member

    Not sure why I don't trust my local radiator shop when I never went to them but way I see it the core is already messed up. If I mess it up worse (kinda hard to do) I will do heater switch.

    Thank you I'm getting all sorts of good ideas that will help me :)
     
    piffey263, Dec 12, 2011
    #11
  12. Warloch

    Warloch Did you say Flattie??? Staff Member

    I have had good luck with MAP gas as well on radiators. Even though I gas weld and such, I take mine to a local guy who then gives me a 1 year on his work...

    That way I don't have to fix my own goof ups.
     
    Warloch, Dec 12, 2011
    #12