How to remove capacitor adhesive

Discussion in 'Pioneer Audio' started by bisonguy, Oct 17, 2008.

  1. bisonguy

    bisonguy Active Member

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    Location:
    Ottawa, Canada
    I am hoping someone can give me a suggestion on how to safely remove the adhesive used to hold some of the larger capacitors on the Pioneer models. I have been re-capping an SX-780 as practice prior to tackling my SX-980. I have now run into the larger capacitors that are held with glue before soldering.
    The glue is very hard and I need something to soften it up that won't damage the circuit board. I have already removed the solder so the only thing holding the capacitors on is the glue.
     
  2. avionic

    avionic " Black Knights " Subscriber

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    I use a exacto knife with a chisel-like blade to chip it away. I'm afraid any chemical softener would have adverse effect on surrounding components.
     
  3. kretinus

    kretinus squanto was a fool Subscriber

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    dumb question, will a soldering iron with a suitable tip soften the glue?
     
  4. Andyman

    Andyman Scroungus Stereophilus Subscriber

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    Well, if it's like the brown goo Pioneer uses on coils in crossovers, the answer would be "no".
     
  5. miklemke

    miklemke AK Subscriber Subscriber

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    I have used a sharp wood chisel with good luck. Just have to be careful to not apply too much pressure.
     
  6. EchoWars

    EchoWars Hiding in Honduras

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  7. Timothy Flath

    Timothy Flath Active Member

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    Location:
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    Why not just leave it? I presume Pioneer chose the glue to be non-reactive to the board and the caps that it held in place...
    Am I wrong in this assumption as I am doing an SA-7800 with the same brown goo on the large caps? It doesn't seem to have corroded any of the surrounding board at all and is rather spongy in feel so it would act as a natural damper for the new caps going in I would think??????
     
  8. loweran

    loweran AK Subscriber Subscriber

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    Location:
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    I use ISO or Acetone to soften it up and scrape it with a dental type tool. Usually if I can get the sharp part of the tool in it, it peels up some. Takes some patience.
     
    Harvestor likes this.
  9. Timothy Flath

    Timothy Flath Active Member

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    Location:
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    I question why - if it was bad for the caps or the board why would they use the stuff to glue down the caps in the first place? Why not just leave it there as a cushion for the smaller sized larger or equal capacity caps that will replace the old ones?
     
  10. loweran

    loweran AK Subscriber Subscriber

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    I think they might have used it since the caps were larger and they were shipping these units across the world. My uninformed hypothesis. I just clean it up as part of the board clean up.
     
    Bill Ferris likes this.
  11. redk9258

    redk9258 Super Member

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    Location:
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    In time this stuff becomes corrosive and / or conductive. Some of this equipment was not meant to be used 25, 30, 40+ years! Best to remove it when you can.
     
  12. Timothy Flath

    Timothy Flath Active Member

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    241
    Location:
    Victoria, BC
    Thank you muchly - will try
     
  13. Sriskie

    Sriskie AK Subscriber Subscriber

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    I use a facial cleaning pad soaked in acetone and a Popsicle stick. Soak, scrape, and repeat. Tedious but it works and will not scratch the boards.
     
  14. txturbo

    txturbo AK Subscriber Subscriber

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    Location:
    Austin, TX
    This is the method that I use. A wide and sharp flat exacto works great. The only problem is that you can’t always get the correct angle of attack. I have had to remove some components on occasion to get the job done. Be careful not to scrape up the silkscreen. :eek:
     
    avionic likes this.
  15. Timothy Flath

    Timothy Flath Active Member

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    241
    Location:
    Victoria, BC
    I just used tools that I had handy. What worked best was a flat head set of tweezers. It was so rubbery that when I grabbed on to a hunk it pulled up a large part of the caked on glue that was flat to the main board. Got most of it but quite frankly I was not all that concerned. I noted no areas of corrosion or damage caused by the adhesive. If anything it preserved the board very well. Also there are not many tracks in the vicinity of the large caps so there is not much in the way of board traces to damage even if there was corrosion. This is a 38 year old amp so I think the team at Pioneer did their homework well when selecting an inert adhesive back in the day....
    It was good an exercise in good house cleaning at the very least.
     
    Last edited: Jan 14, 2018 at 11:06 PM
  16. dcgibby

    dcgibby New Member

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    Judicious use of a heat gun will soften it so you can scrape it off with just about anything.
     
  17. Timothy Flath

    Timothy Flath Active Member

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    241
    Location:
    Victoria, BC
    Worth a try next time. Are you not worried about heat stressing the board excessively and causing issues down the road?
     
  18. dcgibby

    dcgibby New Member

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    Just be careful. You should be okay.
     

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