Warning about really old and well used Marshall 4x12 cabinets

Discussion in 'Cabinets & Speakers' started by Matthews Guitars, Nov 19, 2019.

  1. Matthews Guitars

    Matthews Guitars Well-Known Member

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    If you're looking to buy a used Marshall 412 cabinet and it appears to be "Well used", then before you buy it you should take the back off and then check the cabinet for solidity and rigidity by pushing on the back corners.

    It'd be an even better test to remove the baffle as well, which would remove all bracing support from the cabinet, but you can tell if the cabinet sides are still securely glued just by taking the back off.

    I got a 1960B cabinet recently, a well used one, and when I went to recover it, I found a high water mark in the cabinet about three inches up, and when I removed the back and the front baffle I found that it was a bit wobbly. After removing the tolex it was soon evident that the glue joints had all completely failed. The old glue was crumbly grit like coarse sand. It was no effort to completely disasemble the cabinet.

    I brushed out all the old glue with a stiff brush and glued it back together using the baffle and back as internal braces and used every long clamp I had available (Just enough fortunately) to get it clamped across every joint.

    I suspect that a lot of old Marshall cabinets have suffered the same glue joint failures. But you can't really tell when the cabinet is fully assembled. It's being held together by the baffle, the back, and the tolex.

    My cabinet in question was made in the mid 80s. It's a JCM800 era 1960B.

    DSC_6223_sm.jpg
     
  2. Fret-Shredder

    Fret-Shredder Member

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    Good advice. Thank you. I got lucky with my 1976 cab. It appears to be all original and well cared for before I got it.

    [​IMG]
     
    Last edited: Nov 19, 2019
  3. ampmadscientist

    ampmadscientist Well-Known Member

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    There is no dried beer on this cabinet. Whats wrong with you?:drunk:
     
  4. RLW59

    RLW59 Well-Known Member

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    My mind is blown. Finger joints shouldn't fail like that.

    Makes me wonder if they cut the fingers/slots intentionally sloppy/loose for ease of manufacturing and count on the glue to fill the gaps. The resulting joint would be weaker than a good butt or rabbet joint.
     
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  5. MarshallDog

    MarshallDog Well-Known Member Premium Member

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    Thanks for the heads up!!
     
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  6. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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    Both of my cabinet makers advised against using finger joints due to them loosening from age or water intrusion. They built all of the Scumback branded cabs with 1/2 blind dovetail joints for that very reason. It's hard to pull apart one of those joints.
     
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  7. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Actually the finger joints still had good tension after cleaning the glue residue out. It wasn't the joint that failed, it was the glue. I think it was a urea based glue, which appeared as a white gritty residue.

    Dovetail joints are finicky and I personally do them on my own cabinetry but I think that finger joints are a good compromise for cabinetry, being far superior to rabbeted joints and having about as much surface area as dovetails while being easier to execute.
     
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  8. soundboy57

    soundboy57 Well-Known Member

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    I Never had joint problems other than the 1964 cab that I restored. It was held together
    by the baffle and rear panel screws...and tolex, literally. Those had butt joints and hide glue, though.
    Yours must have had a bad batch of glue or water damage. Weird.
     
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  9. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Well, one corner had a corner protector on it that I'd say was crushed. Clearly the cabinet took a big hit on that corner, though the wood underneath was not damaged enough to be worth mentioning. Still, that was a pretty good shock to the joints.
     
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  10. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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    There were a number of the 4x12 Marshall Handwired cabs sent out with broken finger joints years ago. I got one used, and had my cab guy fix it. But you could see the fingers trying to break through the tolex, and this one hadn't been dropped (no scuff marks on the tolex at least) that I could tell. The glue had failed for sure, but it looked that way on both top corners from front to back. Once it was fixed it was fine, but it was still a PITA to deal with.
     
  11. Trapland

    Trapland Well-Known Member

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    Agreed. No dried beer means it broke from lack of love.
     
  12. ampmadscientist

    ampmadscientist Well-Known Member

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    No spilled beer = no vintage tone. :drunk:
    Did these guys think tone comes from the tooth fairy? (or wat?)
     
  13. BygoneTones

    BygoneTones Well-Known Member

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    Never had this problem with old Marshall cabs, but I have with other brands. I once had a late 70's Hiwatt cab literally fall apart on me when I took the back panel off.

    Marshall cabs tend to be very robust for the most part, but obviously if you mistreat them then they are not completely indestructable. They are not designed to be left in damp conditions, and a lot of people leave them to rot in their garage for decades. If they get dropped on their corner edge thats how you break a cab apart once the baffle and back panel are out.
     
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  14. MickeyJ

    MickeyJ Active Member

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    My gig 1960a cab is so beat up, strips of vinyl torn off, Songlists written on the back in white marker. When moved it actually creaks the joints are so bad, it looks like it was bounced down stairways etc. Sounds great I absolutely love it. I have a new marshall 1960a unloaded cab that someone gave me I was just going to change drivers over but couldn't be bothered. The enlightened will tell us that there is increased resonance in the speaker baffle due to the isolation caused by the broken glue joints, also, the birch ply has been ' sound sculpted', the pores of the ply have been aged by the millions of notes played through it.
     
  15. tomsvintage

    tomsvintage Well-Known Member

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    Is an 80's cab really old ?? Title is misleading.

    Never had this problem with any of my older ( early to mid 60's ) well used Marshall cabs.

    Title should read..."Examine ANY old used cab before buying'

    BTW ~ Nice restoration work.
     
    Last edited: Nov 23, 2019

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