Semi-hollow construction - advice needed...

Discussion in 'Tele Home Depot' started by epizootics, Jun 14, 2021.

  1. epizootics

    epizootics Tele-Meister

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    Hey TDPRIers,

    Two years ago, I built a solid-body guitar for my brother as a gift for his 40th birthday. He wasn't a guitarist prior to that, but he has been playing the guitar in question every day ever since. Recently, he asked me if I would build him a second one, as his playing has become serious enough to to justify having another electric guitar. I promptly said 'yes' :)

    He is a big Lonnie Johnson fan and asked me for a hybrid between Johnson's Kay Value Leader and a Thin Twin (also a Kay guitar). The result is basically the outline of a Value Leader with a Thin Twin-ish pickguard.

    We settled on a hollowed-out sapele body with a 1/4" maple drop top. Said drop top is being supplied by my brother's next door neighbour and friend who is a violin maker - he has a large stash of flamed maple and said he'd happily share some of it with us.

    Here's the top:

    [​IMG]

    And here's where we're at:

    [​IMG]

    The neck is good old French walnut with a wenge fretboard. Frets are stainless - I switched to those a while ago and never looked back. I also fashioned a primitive but functional tailpiece out of thin stainless steel stock (the end of it will be bent once I have the body & bridge ready).

    Inspired by Max Heidemann's work (NoisyShack on instagram), we decided to go with a linen-based phenolics sheet for the pickguard:

    [​IMG]

    It is a humble material that has its charm, in a low-key kind of way.



    Anyway, this will be the hollowest instrument I was have done so far. The plan is to remove a LOT of wood from that sapele blank. Here are the CAD blueprints I made:

    [​IMG]

    On top is the inside of the body. One of the differences with the Value Leader is that the pickups will fit in a mini-humbucker cover that will be attached to the pickguard. The original pancake pickups were top-mounted and very flat indeed. I am worried that the short wood fibers between the pickups could become a liability. I thought of adding a simple X bracing on the underside, as pictured on the plans - is that overkill for a 1/4" maple top?

    Also, it would make sense to me to seal the wood on the inside, but here again, would you say that's necessary?

    Do you see anything I wouldn't have thought of? Some obvious problems I overlooked? Any advice is welcome :)
     
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  2. Peegoo

    Peegoo Poster Extraordinaire

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    That is looking like a really nice build!

    You're using 1/4" maple for the top--which is plenty strong and negates the need for an X brace. Sapele is plenty stiff too, so no need for a solid center block running the length of the body--or even longitudinal bar braces running from the neck block to the tail block.

    There is also no need to apply a sealer or finish to the inside. It's extra work that gains you no benefits, but it certainly will not harm anything by doing so.
     
  3. crazydave911

    crazydave911 Doctor of Teleocity

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    I guess the only issue I see (strictly from my perspective) is the waste of so much fine beautiful wood. To explain, these were made similar to a Danelectro and while the upgrade in wood is great the method lacks a little. I'm assuming you have a sapele blank for the body. Why not split it lengthwise and one half resaw for a lovely back and the other side (if you have a bandsaw) layout in nested fashion the two sides and neckblock. Yes it will be a little deeper but you'd have more beautiful grain without all the unsightly routing and shavings. Just a thought but those sides don't need to be very thick and would make I think a nice bookmatched back.
    I hope you take this in the spirit I mean it I just hate extra, noisy work and like the look better ;)
     
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  4. guitarbuilder

    guitarbuilder Telefied Ad Free Member

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    I've owned the Kays you mentioned. IIRC, they were laminated sides with tops and backs. The pickups are worth more than the guitar to most people today.

    Sapele to me isn't that fine a wood in my opinion ( sorry Dave :)) , so I can see your methodology working out fine. It'll keep it from being neck heavy. The originals were 14 fret joints if I recall.

    You may want to put solid wood under the bridge like a thinline unless you are planning a wooden bridge and trapeze. Dano Convertibles made out of Masonite with little to nothing under them tended to cave in a bit between the neck and bridge after a while.
     
    Last edited: Jun 14, 2021
  5. Lowerleftcoast

    Lowerleftcoast Friend of Leo's

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    My concern would be the possible neck dive. Walnut can be heavy.

    Lucky brother.
     
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  6. Freeman Keller

    Freeman Keller Poster Extraordinaire

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    I have built both semi hollow body, full hollow body and chambered guitars. 1/4 inch is a common thickness for a drop top that will not be carved - most binding is 1/4 tall and that just comes down to the seam. 1/4 inch should support itself very well but I see two humbucker routes and what looks like a tune-o-matic bridge with a trapeze tailpiece. You can screw the pickup rings to the 1/4 inch top but the ToM will either need more wood for the studs or you will have to use a floating bridge.

    ToM bridges usually require some neck angle - be sure to work that out early in your design.

    As far as hollowing out the sapele body blank, we do that all the time. I chamber almost everything I build, but I do leave some structural wood inside for mounting bridges and pickups. I would be very temped in your case to run a couple of spruce beams down the center of the guitar like an ES175 has

    IMG_3525.JPG

    This guitar has a 1/8 thick laminated top and a floating bridge so there are no studs. It has bent sides which is something for you to consider.

    As far as finishing the insides, it is not normally done and you do have to leave bare wood where you will make glue seams.

    Sounds like a cool guitar, I will be watching. If you need any photos of chambered, semi or full hollows let me know.

    Edit to add, the guitar in that picture has a dovetail neck joint. You will need to decide what kind of joint you want to use and make the appropriate block. Many semi hollows have a glued M&T joint, obviously you can screw the neck on also.
     
    Last edited: Jun 14, 2021
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  7. crazydave911

    crazydave911 Doctor of Teleocity

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    Those have bolt on necks, 3 bolts no less
     
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  8. epizootics

    epizootics Tele-Meister

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    Thank you ever so much guys! I'll keep posting pictures as the build goes - on a few occasions, those build threads have been the only way I've had to remember how & in what order I did things.

    Ha, thanks a lot. It kinda felt like I'd gone overboard on a few things. The, erm, 'belt & braces' approach so to speak ;)


    I would tend to agree with you, Dave. It does feel like a lot of wood to turn into dust. But That's the aesthetics my brother wanted to go for, and I really want this one to be as close as possible to what he had in mind...otherwise I might end up having to build him a new guitar every couple of years ;) (which I actually wouldn't mind, it is fun working this way)


    I was actually planning on making a wooden bridge, like the originals (albeit a bit more refined - at least a height adjustment mechanism). I left the tune-o-matic on the drawing for convenience. And I will be using a trapeze tailpiece. Would you say I should keep that bit of wood under the drop top just in case?

    Yup. I will adjust the final depth of the bottom part to what seems reasonable enough to keep the guitar from diving. But European walnut seems to be lighter than most of the American walnut I have seen so far, and a bit softer too (yet very stiff).

     
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  9. crazydave911

    crazydave911 Doctor of Teleocity

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    My favorite habit on these is birch or maple 4mm ply over a well chosen construction grade 2 X 4 lol. I can stain it almost like the original. I even have similar plans next Brotherhood Build lol. Like anything I do, not exact but on same theme. I always put a block under the bridge BTW even though I usually use a wooden bridge. I run my string ground from the metal tailpiece with no issues, I suggest the same. I'll try to find pics of one but no promises :);)
     
  10. nnieman

    nnieman Tele-Meister

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    I am loving this project!
    I love those old kay hollow bodies, I have owned more than a few over the years.

    The value leader I owned was very similar to a danelectro - pretty much entirely hollow.

    No bracing at all.

    I dont think you will need bracing, except maybe to support the tom bridge.

    I build my own version of the galaxie/speed demon - I use african mahogany totally routed out to be hollow.
    I think there are pics on my instagram
    https://www.instagram.com/niemanguitars/

    I love the tailpiece you made, it looks fantastic.

    Nathan
     
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  11. Peegoo

    Peegoo Poster Extraordinaire

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    If you like 'coloring outside the lines' like I sometimes do, you can recess the TOM bridge and obviate the need to angle the neck attachment. Here's a vid that shows you how.

     
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  12. ctmullins

    ctmullins Tele-Meister Ad Free Member

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    That’s a cool look, no doubt.

    But I would not do that with a trapeze tailpiece. Not enough break angle over the bridge saddles.

    Angling the neck 2 degrees is easy, once you make some 2 degree router rails.
     
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  13. E-miel

    E-miel Tele-Meister

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    If you recess the TOM bridge, still make sure the geometry works out. I did recess a TOM bridge on my 2020 bb and still needed 1.5° neck angle.
     
  14. epizootics

    epizootics Tele-Meister

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    Cheers everyone!
    I won't be using a TOM anyway, but I have recessed one in a past build. I find it to be more hassle than angling the neck pocket :D

    There will be angle here too - as ctmullins said above, I want to keep a decent break angle from the bridge to the tailpiece.

    My main concerns now are (1) how to wire everything together without adding a cavity at the back of the pots and (2) getting a piece of perspex wide & thick enough to make a big router base for the hollowing out. I actually go a quote at $100 for a 20x20x0.39" piece of perspex from a local business. This is more than the cost for all the materials on this build.



    Some really cool pictures in there! Both of the guitars and the ducklings. I love ducklings. I'd have ducks in my flat if my wife let me :)

    Good call on the grounding. I had managed to completely forget about that. This will be my 16th build and I still forget about grounding half the time. I think I'm hopeless :)
     
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  15. crazydave911

    crazydave911 Doctor of Teleocity

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    Either one of mine or a friend's

    received_296185252034655.jpeg

    The Value Leader Bass, pretty rare
     
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  16. guitarbuilder

    guitarbuilder Telefied Ad Free Member

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    You don't really need acrylic to make an auxiliary base. I've just used wide wood or plywood in the past. Make the bit hole big enough so that you can see through it some while you are routing.
     
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  17. crazydave911

    crazydave911 Doctor of Teleocity

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    It's his, I noticed not the tuners I use
     
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  18. nnieman

    nnieman Tele-Meister

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    I agree 100% - use whatever you can get for free or cheap for a router base.

    Nathan
     
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  19. epizootics

    epizootics Tele-Meister

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    Indeed. I try never to buy 'new' bits of plastic unless I really have to. The crazy part is that thick acrylic sheet stock is everywhere these days, in the form of little cages around tills in supermarkets and offices, but I couldn't find anyone locally who would sell me offcuts.

    Ply it'll be.

    I received the top through the mail yesterday, it's a beauty! I am going to make a scraper plane from scrap have in my shop to clean it up as it still is quite rough. More soon...
     
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  20. epizootics

    epizootics Tele-Meister

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    OK, things seem to be moving forward in an almost f**k-up free manner. I routed the outline and drilled out most of the wood.

    I do wonder, though. The wood moved a bit, which I expected after removing so much of it. The center block is now about 0.018" lower than the sides (but still level longitudinally with the fore and aft of the body). Gluing the maple top will create further movement. Do you guys think I should leave it as is and glue the top on, or plane the body first?

    20210712_093628.jpg
     
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