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  1. #14
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    Oct 2011
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    Chicagoland Area
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    With an O/A set up, use a #0 tip
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Liberalism-Ideas so good they mandate them

  2. #15
    Join Date
    Mar 2013
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    Cherokee Co. Texas
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    I do a lot of these, Turbotorch, "B" tank, 15%. Just dont direct flame on cap tube. Heat the copper only, use 15% sparingly so capillary attraction doesnt pull the sil-phos in too far and plug the end of the cap tube.

    Merry Christmas.

  3. #16
    Join Date
    Dec 2013
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    Thread Starter
    I appreciate all of the advice. I got a few old evaporators laying around , will just practice on them first. This company hired me out of technical school part time with no one to train me. The last service tech they had quit over a year ago.

  4. #17
    Join Date
    Mar 2007
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    In the Conservatory with a Lead Pipe
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    One thing I do is when un brazing the old cap tube is to wiggle it to spread the copper and old solder to make way for the new cap. Most of the time if you don't the new cap won't fit.

  5. #18
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    Oct 2011
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    Quote Originally Posted by Jusam View Post
    I appreciate all of the advice. I got a few old evaporators laying around , will just practice on them first. This company hired me out of technical school part time with no one to train me. The last service tech they had quit over a year ago.
    Keep this in mind when practicing brazing. The copper in the evaporator coil is probably thinner than any other copper you will see. It takes a lighter touch than regular copper pipe. You will also find along the way, a lot of copper clad steel and stainless steel. These also needs to be treated in their own special way. Practice identifying pure from clad. A few examples of copper clad steel is driers, sight glasses and compressor ports. Danfoss txv's are copper clad stainless, Hoshi evaporators are stainless clad copper. You will also find just plain stainless piping. Heatcraft is using some micro channel condenser coils which are made from aluminum. You can do a search of this site and find out different techniques on how to approach each.
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Liberalism-Ideas so good they mandate them

  6. Likes trippintl0 liked this post
  7. #19
    Join Date
    Sep 2008
    Location
    Western PA
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    Quote Originally Posted by rkevins View Post
    was taught in tech school ( a long time ago) to put some oil off your nose or drop of ref oil on the end of the cap tube so solder would not stick to end of tube

    I want to grab onto this suggestion. It is an interesting idea for sure, but I don't know for sure if it would work or not.

    Get even dirty, oily copper hot enough and throw rod at it and it'll stick. I know, I've done it. The heat tends to just burn the oil away.

    At a more 'normal' brazing temp, there might be something to this, though.


    A proper insertion depth of the cap tube is important. Get it deep enough and the solder doesn't reach the end TO plug it up. Although, push it in TOO FAR and it may contact something on the inside and not feed properly, so it is a balance.



  8. #20
    Join Date
    Sep 2009
    Location
    Stumptown,USA
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    I was a Major Appliance repairman for 27 years before switching to commercial and i have brazed in hundreds of cap tubes. When I worked for RCA Service Company (1977 to 1979) we only used easy flow 45 high silver brazing alloy (1100 degrees) and soft flame Prest-O-Lite twin tip torches (acetylene and air) they had not invented turbo torches yet. A turbo torch (acetylene and air) with a #2 or #3 tip should work just fine and you can use 15% phos copper stick or easy flow 45 with flux which ever you feel more comfortable with. Tilt the tubing downward (so the alloy has to run uphill,) put the cap tube in about an inch and bend your brazing rod over at half an inch when that half inch is gone don't add any more alloy. Put your flame on the larger tube and when it is a dull red apply the alloy, inspect with a mirror and that is it. Inserting the cap tube far enough and not using too much alloy is the trick. JP when using easy flow 45 I always rubbed my index finger on my greasy nose and wiped it around the end of the cap tube (the high silver alloys are more finnicky about clean tubing). It works!
    Challenge yourself, take the CM test --- Certificate Member since 2004 ---Join RSES ---the HVAC/R training authority ---www.rses.org

  9. #21
    Join Date
    May 2016
    Location
    Southern California
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    Just did my first ever compressor replacement today on a merchandiser, holy moly I wish I read this thread before tackling the cap tube!

    Favorite suggestion is the wiggle the tube out when de-brazing it, I'll remember this next cap tube I remove. I spent an inordinate amount of time trying to get the left over material out in a really tight spot. When boss finally got back to me he told me to run nitrogen and heat it back up. Worked like a charm, was the last braze so only two holes to flow out of heh. In addition to being tight, the cap tube had to go up into the pipe. Tried all sorts of configurations, even had to start over and cut the tube a bit, eventually the monstrosity sealed up and I was able to continue. Any tips on getting a cap tube going up into a pipe? I shoulda took pics, felt like a special sort of hell getting it sealed. I'll look into getting a smaller tip, perhaps that'll help out.

  10. #22
    Join Date
    Mar 2007
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    In the Conservatory with a Lead Pipe
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    If there isn't much to work with and you buggered up the original spot some things you can try are wick away the braze with fresh clean captube that fits. The old tube is good for this if you kept it. Keep heat on the captube as you pull it out. If you snap off the captube a last resort would be to tear it open mash it back down with pliers and fill the gap or push what's left in and hope for the best down the road If you are working inside a box O/A torch won't get snuffed out from lack of O2.

  11. #23
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    Jun 2011
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    NE Ohio
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    Quote Originally Posted by Jusam View Post
    I appreciate all of the advice. I got a few old evaporators laying around , will just practice on them first. This company hired me out of technical school part time with no one to train me. The last service tech they had quit over a year ago.
    carefully heat the larger pipe first then it should just be a quick swipe of the capillary tube with your torch as you apply the 15 %, always run dry nitrogen when brazing especially when brazing a capillary tube
    "All that is necessary for the triumph of evil is that good men do nothing." (Edmund Burke)

  12. #24
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    Aug 2002
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    Southold, NY
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    Quote Originally Posted by JohnnyZ View Post
    Just did my first ever compressor replacement today on a merchandiser, holy moly I wish I read this thread before tackling the cap tube!

    Favorite suggestion is the wiggle the tube out when de-brazing it, I'll remember this next cap tube I remove. I spent an inordinate amount of time trying to get the left over material out in a really tight spot. When boss finally got back to me he told me to run nitrogen and heat it back up. Worked like a charm, was the last braze so only two holes to flow out of heh. In addition to being tight, the cap tube had to go up into the pipe. Tried all sorts of configurations, even had to start over and cut the tube a bit, eventually the monstrosity sealed up and I was able to continue. Any tips on getting a cap tube going up into a pipe? I shoulda took pics, felt like a special sort of hell getting it sealed. I'll look into getting a smaller tip, perhaps that'll help out.
    NEVER De-Braze a cap tube, discharge line, Accumulator or several other components. You do not know if the line is filled with oil and a flame thrower will be created.

    Cut the cap tube
    Cut the discharge line
    cut the suction line

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  14. #25
    Join Date
    May 2016
    Location
    Southern California
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    Quote Originally Posted by pecmsg View Post
    NEVER De-Braze a cap tube, discharge line, Accumulator or several other components. You do not know if the line is filled with oil and a flame thrower will be created.

    Cut the cap tube
    Cut the discharge line
    cut the suction line
    Thanks, and I agree on cutting anything the cap tube is connected to. I guess I had to learn by a experience. The instance I'm describing both ports were right next to each other with less than half an inch separating them, maaaaaybe an inch and a half poking out from the top. I did attempt to cut the tube after trying to debraze by shoving the adjacent tube up and pulling the one I needed down. If I did that before hand I might've succeeded with way less struggle. Boss usually whips it out no problem and figured I could do the same...nope! . :-/

    With regards to the oil, I definitely cut the suction and discharge, and I know you're supposed to cut the FD, but would you say the oil is a concern on fractional HP systems? 9/10 I'm working on 1/3 to 1/2 hp systems.

  15. #26
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    May 2016
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    Southern California
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    Quote Originally Posted by itsiceman View Post
    If there isn't much to work with and you buggered up the original spot some things you can try are wick away the braze with fresh clean captube that fits. The old tube is good for this if you kept it. Keep heat on the captube as you pull it out. If you snap off the captube a last resort would be to tear it open mash it back down with pliers and fill the gap or push what's left in and hope for the best down the road If you are working inside a box O/A torch won't get snuffed out from lack of O2.

    Thank you sir! Post saved for future tough spots.

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