1960b Build - The Joints

Discussion in 'Building the Classics' started by DistrictOfJP, Nov 25, 2019.

  1. DistrictOfJP

    DistrictOfJP New Member

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    Greetings MF! I'm starting a 1960b build project and expect to ask a few questions along the way from the braintrust here.

    I have a source for 5x5 5/8 BB and actually already have one set of hardware (with shoutout thanks to the screw thread), really just waiting for this cold snap to end so I can get the tools outside and get cuttin.

    I had it in my head when I started planning that I would use this lock-mitre router bit I've had forever and never used, even though I know Marshall used finger joints it just seems easier since I'd have to build a finger joint jig and then work all that out. My question for the forum is if this joint is any concern. Right now I am going only a clear oil finish ala Segeborn but am not opposed to tolex as I have experience with a chopped Laney combo head project I just completed.

    I've seen youtube videos where a butt joint was used so I don't think I should worry, again just looking for wisdom.

    thank you!
    jp
     
  2. pedecamp

    pedecamp Well-Known Member

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    I don't think it matters how you build it as long you glue and screw it together to make it strong and use proper bracing inside. :yesway:
     
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  3. Geeze

    Geeze Well-Known Member

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    +1!!

    The only reason I use finger joints is for the look on bare wood. With today's glues like the Titebond series increasing surface area for joint durability isn't necessary. If you block the corners you can 'hide' the screws [if you choose to use screws] on the inside. If you plan to just seal the wood - test a piece to see if the finish makes the wood seem blotchy. If it does use a gel stain [doesn't penetrate] for an even look.

    Welcome to the forum!

    Russ
     
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  4. DistrictOfJP

    DistrictOfJP New Member

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    Great advice - thank you! The most interesting thing I've learned so far is that BB comes in 5x5 sheets, and two of them almost exactly produce two Marshall 4x12 cabs at dimensions 29.75 x 30.25 x 14.25.
     
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  5. Micky

    Micky Well-Known Member VIP Member

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    I would use finger joints for exposed wood, and butt joints for covered cabs.
    Both can be extremely strong.
     
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  6. pedecamp

    pedecamp Well-Known Member

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    My dad has a jig I gotta get my hands on and try again, I tried to use it to do finger joint once and it tore up the plywood ends when I routed it, not sure what happened but I'd like to try it again. My dad has an awesome woodshop loaded with industrial grade machines, its all gonna get sold in the next few years hes almost 90 and doesn't use it any more, I'll grab all the hand tools but I don't have room for large machines unfortunately.

    Meanwhile I just butt joint, glue and screw and counter sink the screws and fill it with wood putty. :yesway:
     
  7. Joey Stockton

    Joey Stockton New Member

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    If you are having problem with the wood tearing out, try using a sacrificial backing board... problem solved. I agree with the above comments. I will use finger joints or dovetails on an exposed wood cabinet, but if it is getting covered, I use Titebond and pockethole screws. It is NOT going to come apart!
     
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  8. pedecamp

    pedecamp Well-Known Member

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    Yes you just jogged my memory, I do remember reading somewhere about using a sacrificial backing board to keep from tearing up plywood when routing ply ends. Thanks! :yesway:
     
  9. proxy

    proxy Active Member

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    just epoxy them and everything will be fine ....
     
  10. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Longtime experienced woodworker here. I recommend only finger joints and dovetails for maximum strength. Finger joints for plywood, dovetails for solid wood.

    No to rabbet joints, no to butt joints unless they're reinforced internally. Butt joints in particular are very weak, especially on plywood. Failures at ply laminations are easy to induce whether the cabinet is covered in tolex or not. Rabbet joints are OK for securing a baffle into a cabinet but that is literally
    the only thing I'll use a rabbet joint in a speaker cabinet for.
     
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  11. Scumback Speakers

    Scumback Speakers Well-Known Member Sponsor

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    Finger joints are ok, dovetails are better, in my experience. Stronger, tighter, interlocking.
    [​IMG]
     
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  12. JohnH

    JohnH Well-Known Member

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    I love those dovetails!

    But if you have only moderate skills and tools, and are covering the cab, I think a batten-reinforced butt joint, screwed and glued is as strong as you can get. I build mine with 19x42 battens, with the 19mm face against the inside of the panel that goes to out the corner. Screwed from the outside into the 19mm face and from the inside through the 42mm face so each screw gets plenty of edge distance. You can then round of the corner without hitting any screw heads
     
  13. DistrictOfJP

    DistrictOfJP New Member

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    That's the look I am going for right there, thank you! - Love the beading and the slight bevel of the speaker baffle. The finger joints really shine here. I wouldn't do anything to the finish. natural BB should stay IMHO.
     
  14. Matthews Guitars

    Matthews Guitars Well-Known Member

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    I don't prefer dovetails for plywood cabinets because every time I've done that, I always got too many small pieces of ply wood chipping off for my tastes. If you can do it wihout those chipouts, yes, that'd be the best way to go.

    I need to find a box joint fixture that allows me to do tight pitch finger joints like found on Marshall cabinets.
     
  15. DistrictOfJP

    DistrictOfJP New Member

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    That's partly why I am going to try the miter lock joints, it would be much work for me to get quality finger joints with 30 x 14 stock especially if I decide to tolex in the end.
     
  16. Rotorcraft230

    Rotorcraft230 Active Member

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    641F145C-A558-478D-B976-2B899CB03543.jpeg I just recently refinished my JCM800 1969A and B can and here is what the joints look like with no Tolex. They are stained and clear coated
     
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  17. Rotorcraft230

    Rotorcraft230 Active Member

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    Here is a few more pics B0D1925F-F9EB-462C-BCE3-D5A57DDA54C3.jpeg E4FAAC85-88DB-4461-B0EB-5F051B2C23AA.jpeg
     
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  18. DistrictOfJP

    DistrictOfJP New Member

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  19. Rotorcraft230

    Rotorcraft230 Active Member

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    D29F5C28-A6C0-4C3B-9A27-88780D611F67.jpeg Thanks I stumbled across these cabs for 135 bucks, but the G12-65 were gone. The cabs were empty but I suppose that’s ok. We’ll fill em eventually.
     
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  20. Exojam

    Exojam Well-Known Member

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    Find a storage place!

    Your pop probably has stuff of quality you will never be able to get your hands on later on.

     

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