HELP replacing rivets - JCM900 SL-X

Discussion in 'General Electronics Chat' started by wolf1419, Dec 16, 2008.

  1. wolf1419

    Thread Starter Active Member

    Nov 1, 2008
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    0
    Hi,
    I tried this on the Marshall Forum, but didn't get much interest. I'm trying to remove some rivets on this amp to replace a broken top vent and they do not want to come out. They only go partway into the wood, so have no fastener or nut, etc. on the opposite side. Is there a trick to this......they are also the same rivets for the corners, hardware, etc......anybody have hands on experience with this.............:confused:
     
  2. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    I've got no experience with your particular problem. I'm sure you already know how to drill out ordinary rivets using a drill with a diameter the same as the outer "barrel" of the rivet -- by barrel I mean the part in the hole, not the part outside the hole, which is bigger. If these are special rivets that expand into the wood on each side of the hole, you still use a drill the size of the hole to remove them.

    You need to center punch rivet before you drill it out. Get one that's really sharp and just tap it -- you don't want to damage the circuitry inside the amp! Also, figure out how deep the wood is -- you don't want to drill beyond it lest you damage something inside the cabinet! On a drill press, if you have one, set it for a depth that is shy of the thickness of the wood. If you don't have a press, tape around the drill bit near its tip and to the desired thickness. Drill all cabinet rivets, then remove the vent. Good luck!
     
    Last edited: Dec 16, 2008
  3. bertus

    Administrator

    Apr 5, 2008
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    Hello Ron,

    Is it possible to make a picture and place it on the forum?
    Is the rivet now mounted in the wood part?

    Greetings,
    Bertus
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    PRS idea is good. Use a drill and a drill bit with a diameter less than the hole's diameter the rivet plugs in and your job will be done. Just drill the rivet in the center (on the small hole on it) and it will get out. Take care not to put the drill more than 10mm in because you may destroy the circuitry.
     
  5. wolf1419

    Thread Starter Active Member

    Nov 1, 2008
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    0
    This is probably what they look like prior to installation. Mine are still installed. I also want to thank PRS & MIK3 for your contributions, as that is probably the answer. I did get one guy on the Marshall Forum, and said he thought he heard that they have to be drilled out, but you guys have clarified the process quite well. I was hoping it would be less drastic, but if that's the only way, then that's it. Hey Bertus, nice to hear from you!
    Any other suggestions, tips, tricks out there will be well appreciated.
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,645
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    Hello Ron,

    When you want to drill them out, start with a small drill.
    This is to prevent drifting away and damage the housing.
    Try to aim at the center of the rivet.
    When this is done you can use a larger drill and try to drill them out.

    With what do you want to replace the rivets after you have done it?

    Greetings,
    Bertus
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,675
    899
    The original directions given by PRS is what works with regular aircraft rivets or pop rivets (i.e., center punch, drill same or very slightly smaller).

    Your rivets look threaded. So, I would go a little undersize and then use a LH screw extractor.

    The major problem with drilling a lot undersize, then going bigger is that the second drill may hog in, particularly if the rivets are brass and not steel. If it hogs in, you will spin the rivet, which makes any additional drilling much more difficult. If that happens, take a chisel and drive it into the head from the side to keep it from turning, then try to drill while holding the chisel. If all else fails, you may need a vise grip on the head to keep it from turning, but that will have a greater chance of marking the underlying material.

    John
     
  8. wolf1419

    Thread Starter Active Member

    Nov 1, 2008
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    I'm very impressed by the detailed help from members on this site. I've tried a few others, but this is the BEST BUNCH OF PEOPLE!!

    I don't think the rivets are a continuous thread like a bolt, just individual threads for grabbing wood.

    Bertus helped me through a rather drawn out learning experience and repair a while back, probably simple stuff to many of you, but he taught me a lot of the basics of electronics, diagnosis, etc........and to answer your question, I'm planning on using the same(new) stock rivets for an original repair.

    I don't even have the parts yet, but wanted to know how much of a job this would be before I tackle it, as the vent is only broken on the corners and doesn't look that bad, but I wouldn't mind just replacing it, as I do a bit of electronic, grille and tolex repairs, refurbishing older amps and guitars, now it's the hardware that's the weak link on this one.
     
  9. bertus

    Administrator

    Apr 5, 2008
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    Hello Ron,

    Succes on the "hardware" part.
    I hope things work out.

    Greetings,
    Bertus
     
  10. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    Wolf, it sounds to me like you are a musician, not a mechanic. What I said above is right. But I have to add this. Do not use a small drill bit then a large drill bit -- what happens in this case is that the large bit propells itself into the hole because of the spiral bevel of the bit. If you use a drill press you can resist this, but if you use a hand held drill, you may end up drilling right into the cabinet's goodies.

    So here is how you do it: Tap tap tap with a sharp center punch. Then drill into it with a tiny bit about 1/8 of an inch. No more. If your bit that is the same size as the original hole does not get the the point, then drill out that little hole with a bit that is just a little bit bigger. But only go in 1/16 to 1/8 of an inch. Just a dent, so to speak. For if you go deep, the large bit that you ultimately use will dig in and you'll probably get surprised by the fact that you drilled through the whole cabinet and smashed some electrical circuits. Be carefull! ;)
     
  11. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    It's a tube amp, right?

    You may want to gently remove the tubes before you start pounding/drilling on the rivets.
     
  12. wolf1419

    Thread Starter Active Member

    Nov 1, 2008
    117
    0
    Nice detailed explanation....appreciate that!

    I'm actually a disabled(CFS) previous musician/studio guy that does collecting and some repairs/refurbs as health permits, get to play/test various unique gear and eventually sell/trade once it is back to mint/near mint condition, as my therapy, using my prior knowledge and continue learning some new things, at my own pace. It keeps me going........

    SgtWookie & my fellow gurus...I might want to take the whole chassis out when I do this to avoid all potential problems.....
     
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