Any way to apply heatshrink after circuit has been soldered closed?

Discussion in 'Archived Threads 2001-2004' started by KevinYao, Apr 16, 2002.

  1. KevinYao

    KevinYao Auditioning

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    I assembled my first kit last weekend and I made a mistake in soldering the end of an ofc (oxygen-free copper) wire to the terminal of a tweeter without first sliding the heat shrink up the wire. Now it's all soldered together and I can't get the heat shrink on the wire (since the other end of the wire is also soldered to the rest of the cross-over network).

    Any suggestions? Would wrapping electric tape around the exposed lead do just as well? Or is there a kind of heatshrink that can be wrapped around after things have been soldered together?

    I tried to unsolder the joint, but after 2 minutes, the solder still wasn't getting hot enough to let the joint loose. My solder gun is pretty weak though.

    Actually, how bad is it to leave it exposed to the air?
     
  2. Bill_Weinreich

    Bill_Weinreich Second Unit

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    If you are worried about the exposure, don't. A good solder joint should be just fine. But if your really worried, go to the local marine or auto parts store and pick up some liquid electrical tape. Just brush it over the connection. It dries relatively fast, is waterproof, flexible, and comes in colors.

    Bill
     
  3. KevinYao

    KevinYao Auditioning

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    "If you are worried about the exposure, don't."

    By "don't", did you mean don't worry about exposing the wire to the air, or did you mean don't use electric tape to cover it up?

    By the rest of your message, I'm guessing you meant don't use electric tape (correct me if I"m wrong). Anyways, I'll try to get a hold of that liquid electric tape stuff. Thanks.
     
  4. Bill Kane

    Bill Kane Screenwriter

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    My son in law brushed this stuff over his car battery terminals! Looks cool, but it seems permanent. Dont know if a heat gun is needed to remove it, tho.
     
  5. Jeff Rosz

    Jeff Rosz Second Unit

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  6. Bill_Weinreich

    Bill_Weinreich Second Unit

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    Kevin,

    What I meant about the exposure was that even with standard heatshrink there will be exposure to air. It is relatively rigid after shrinking and gaps at the end will occur. To eliminate this you would need an adhesive lined heatshrink for a more air tight seal. The glue on the inside will melt and squeeze out to the ends conforming to the wire/terminal.

    Judging by your post I wasnt able to determine if the reason behind this concerne is because its OFC wire. OFC has to do with the manufacturing. When the wire is annealed(reheating to restore flexibility), it is done in an oxygen free environment to keep oxygen from rebinding with the copper which could allow oxidation. It has nothing to do with allowing air to enter the cable after construction.

    Bill
     
  7. Marc Bodin

    Marc Bodin Extra

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    Add a bit more solder to that joint while you are heating it up and it will flow no problem, then you can puy on some heatshrink. Electrical tape will work as well, I prefer heatshrink though. Leaving it exposed to the air will not cause problems, but if you are really worried about it you could smear some dielectric grease on the connection.
     
  8. KevinYao

    KevinYao Auditioning

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    Bill,

    BTW, I don't know if its implicit, but the ofc in my kit is composed of strands (like speaker cable), I'm not talking about just a single wire.

    I'm not sure if the heat shrink provded in the kit (it's the Paradox 1 kit from GR-Research) has those qualities you mention to squeeze out the air, but when I used the heat shrink on other parts of the circuit, I did see this translucent stuff on the inner lining of the heat shrink appear as I applied heat on it. Would that be what you're describing?

    I thought that the purpose of the heat shrink was what you described - squeeze out the air to prevent any oxidation. Why else would there be a heat shrink in the kit - prevent shorts from stray strands?

    The consensus so far however seems to be that I shouldn't be worrying about oxidation of the ofc. If that's the case, I may just leave well enough alone. I was just concerned that the sound would degrade over time if I left the ofc exposed.
     
  9. Marc Bodin

    Marc Bodin Extra

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    Unless you plan on dunking those components in the salt chuck, I wouldnt worry about it. Heat shrink is meant to insulate, it wont protect against corrosion by itself.
     
  10. Bill_Weinreich

    Bill_Weinreich Second Unit

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  11. KevinYao

    KevinYao Auditioning

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    Should have done this in the first place. From the kit's designer's web site :

    "The Paradox-1's series crossover utilizes an air-core foil inductor and is wired point to point using only oxygen free copper wire. Plus, each connection is sealed with glue-filled heat-shrink to prevent oxidation of the wire."

    I suppose the designer is just being anal (I mean that in a GOOD way Danny, in case you're reading this).
     
  12. Saurav

    Saurav Cinematographer

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    I believe the heat shrink provided with the Paradox 1 was glue-filled. I've tried Radio Shack heatshrink, and it sucks compared to that stuff. It caught fire twice [​IMG] I was using a cigarette lighter, which isn't the recommended tool for the purpose, but it worked fine with the heatshrink Danny supplies.
     
  13. KevinYao

    KevinYao Auditioning

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    Saurav! I remember seeing you post at AA. You're comments helped me choose this kit.

    I was actually also using a lighter for the heat shrink on the first speaker, and then I got so tired of burning my fingers that I broke down and bought a heat gun for the second speaker.

    You still using the WAV8's to power the Paradox's?
     
  14. Wayne A. Pflughaupt

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    There really isn’t any reason to heat shrink a connection to a speaker. Heat shrink is generally for insulation (as has been noted). There is little-to-no danger of a short.
    Not to mention it is a risky proposition to solder connections to a tweeter, since their voice coils are delicate.
    Kevin, if you really did this...
     
  15. KevinYao

    KevinYao Auditioning

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    Wayne,

    Thanks for the info. Actually, I think I was saved from my own ignorance by my weak (and failing) solder gun - the tweeter sounds fine at the moment. Unless there are some other symptoms of a burned out tweeter...

    Based on your info., it looks like I shouldn't risk appyling the solder gun to the tweeter terminal again (nor do I need to).
     
  16. Wayne A. Pflughaupt

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    Kevin,

    It looks like your tweet survived the “ordeal.” The voice coil would have burned through or become “open” - similar to a blown fuse – and the tweeter would not work at all.

    However, the coil windings could have warped or otherwise disfigured; this may or may not cause audible artifacts. Also possible scenario is where the coil was about to open but “didn’t make it.” In this case the tweeter would probably sound fine but will likely be the first one to fail down the line.

    If the tweeter is audibly damaged it will be apparent with some program content more than others. “Busy” program signals, like rock, country, rap, etc. can mask the problem. The best way to check for a damaged tweeter is with simple acoustic music with more-than-average high frequency content. High notes on a piano, oboe or soprano sax are good program sources to “aggravate” a questionable tweeter. Listen for distortion, buzzing, etc.

     
  17. Brian Bunge

    Brian Bunge Producer

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    Precisely why I always use push on terminals on drivers! Why risk damaging them with a soldering iron?

    Brian
     
  18. Danny Richie

    Danny Richie Stunt Coordinator

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    Hello all,

    I replied to Kevin's question via e-mail already, but since there seams to be some questions here on the matter I thought I might clear up a few things.

    Bill is correct about OFC being part of the manufacturing process. The wire is manufactured and/or sealed in an Oxygen free environment.

    Higher purity copper will oxidize more rapidly than wire that has a low purity (mixed with other metals). Our wire was selected specifically due to a high purity.

    The sealed jacket does prevent oxidation from occurring other than what passes into the openly cut end.

    The wire that goes out in our kits is multi-stranded, 16 gauge, oxygen free copper.

    Wire that is striped and left exposed to the air will rapidly begin to oxidize.

    I have had stripped pieces laying around for several weeks and even a few months exposed to the air. Even if a piece is left exposed for a few weeks and it is then stripped again further back a clear difference in oxidation can be seen on the wire.

    High frequencies do travel on the surface of the wire, so oxidation with eventually effect the sound in the highs.

    Secondly, yes I am a bit anal about the details. Yes, I intend for our customers to build our speakers in a way that will proudly reflect there performance capabilities.

    The heat shrink provided is glue lined. It is over three times the price of non-glue lined heat shrink, yet I keep buying it and sending it out with our kits. It will seal off the wire and will keep oxidation from occurring.

    The solder that comes in our kit is high grade, audiophile quality, 4% silver solder from SCI.

    I intend for our customers to use this stuff.

    Push pins are inferior sonically.

    I could not bare the thought of my signal that is sent through thousands of dollars worth of components, carried by cryogenic treated Geortz speaker wire, then through foil inductors and custom made caps to have to pass through an Aluminum push pin to get the signal to the drivers.

    I want the OFC wire soldered straight to the terminals.

    Kevin, Having your soldering gun on that tweeter terminal for two minutes is way to long. De-soldering should only take about 2 seconds and 3 to 4 at the most.

    But, I know you did not hurt anything.

    How?

    The tweeter terminals are mounted on a plastic piece that holds the diaphragm. The very first thing that goes when it is over heated is the plastic. It will melt in half before the heat can build up enough in the thin wire lead to begin to hurt the voice coil.

    Now here is the best advise you received....

    Bill recommended some liquid electracal tape. This would probably seal the wire just fine. Don't be afraid to lay it on heavy and cover all of the exposed wire and its connection.

    Regular electrical tape will never seal it.

    Danny Richie
     
  19. Saurav

    Saurav Cinematographer

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  20. jeff lam

    jeff lam Screenwriter

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    Kevin/Danny,

    Good to see you two drop by the HTF.

    Kevin, if you need help with the soldering, you can come over and use my iron and I'll try to help you out if you still need it. So you decided to go with the P1's huh?

    I agree that the heatshrink (and all the components/solder for that matter) that Danny provides is far superior to any other I have worked with so far. The quality of all his stuff is excellent!!!
     

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