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Thread: sawing a log and reassembling it WITHOUT warping?

  1. #1

    sawing a log and reassembling it WITHOUT warping?

    hello!

    I'm building a hifi tube amplifier into a carved tiki head. I start with a log that's roughly 12" wide and 14-20" tall, carve a tiki face into it, then bandsaw the log in half, hollow out the insides to hold all the electronics, and bolt the two pieces back together using machine screws and threaded inserts arranged up the sides.

    My problem is that the two sides of the log warp away from each other and my screws no longer line up to the inserts, so the pieces don't fit cleanly back together. Plus, I have unsightly gaps between the pieces. I could use some help and addressing this issue as I don't have a ton of woodworking experience.

    --> Waiting several years for the logs to dry is sadly not an option <--
    And even if it were, there would surely still be minimal warping of the two pieces that would misalign my screws + inserts.

    The amp must be able to come apart for maintenance, but maintenance does not need to be performed often.

    What solutions are there for reassembling logs that have been ripped this way? I don't see a ton of examples out there which leads me to believe this is a pervasive problem. One option I've considered is to bolt one side of the pieces together and have all of the warping expressed on the opposite side. The overall damage is worse but I could conceivably cover over the gap with a sliding plate. This option doesn't allow for both sides to be supported during transport, but then these items aren't meant to be moved very often.

    Would sealing the wood stop warping? I haven't tried this, but again, even minimal warping would thwart my strategy of machine screws + inserts.

    Another option is to leave the shell of the log intact and hollow out the interior from the two ends. This poses some challenges with the wiring but feels like the best option for presentation. I should also be able to cut out an access port in the back and use the cut-out piece as a hinged panel without any warping, correct?

    pictures attached. I'm not worried about the little splits/checks in the log, just the large gap that opens between the front and back halves. The second picture is a top view; the small holes are for ventilation, the larger hole is in the center of the pith in a vain attempt to slow the movement.

    any other suggestions welcome! thank you!

    earl1.jpgearl2.jpgearl3.jpg

  2. #2
    Join Date
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    You are trying to fight a battle that's going to be extremely difficult to win. "Logs" don't really dry down equally, so you are always likely going to have a moisture imbalance even if you waited for many years. Coating with a sealer (typically on the ends) is to slow down drying to avoid radial cracking in the case of logs. I suspect that about the best thing you can do is joint the faces of the rip line after you hollow and get them gued back together immediately. You may need to do a little hand work to refine the joint to reduce its visibility.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  3. #3
    Hollowing out the log to make a tube with somewhat uniform wall thickness and open top & bottom should work OK. The top & bottom could have separate applied pieces.

    Look up 'band saw boxes'. Splitting in half and then hollowing out the halves, or all with one cut- either way would take a very large band saw.

    The wood is always going to shrink more around the circumference than other directions, and will continue to move like that after it is dry. Taking away the middle allows the outside part to shrink without (as much) cracking.

    In timber framing, sometimes a saw cut is made along the length in to the center, so that the shrinkage happens there instead of other random spots.

    Once the wood in your pics has dried more, the seam could be re-cut for a better fit. Maybe the gaps could become part of the design- how about inserting some tiki ears?

  4. #4
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    Wood moves when it dries and it moves every spring and winter from atmospheric changes. It is a law of nature.

  5. #5
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    Definitely need to wait longer for the log to dry.
    At minimum 7 years
    Aj

  6. #6
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    As Norm would say, celebrate the joint. Put some ears, spears or palm leaves coming out of the joint to hide it. Maybe hang a snake or monkey over the joint. Dreadlocks?
    Bill D

  7. #7
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    This just isn't going to work. If you absolutely just have to have this look, then start with 8/4 stock, square it, then laminate/carve/stain to make it "look" like a log. You won't have to hollow anything this way either.

  8. #8
    Join Date
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    Personally, I don't think you can do what you're trying to do successfully, because of the carved inset where you're hanging the tubes on the outside. If you wanted a whole round log, then hollowing out the log and drying it as a tubular shell would work. But for that to work you need a reasonably uniform thin shell with the interior, small diameter growth rings completely removes, and your tiki head requires that no be the case. If I were given the project as a must do, I would try the following:

    1. Commit to building it as a shell, as nearly as possible. That means, removing any wood you can to get the thicknesses down to less than 1" everywhere. It also means that the top and bottom will have to be "floating" inserts into the shell, not integral parts of the piece.

    2. Split the log. Ideally, I'd actually split it, not saw it, but either way, get the log into two pieces.

    3. Do all the hollowing implied by 1, above.

    4. Dry the resulting form. It'll take months, if you air dry it, so if you're in a hurry, get a massive microwave, or build yourself a plastic mini kiln, but get the wood down to 6% moisture. The wood is going to crack to some degree in the face carving when you do this, but it's a tiki log head, so those cracks are just features.

    5. When it's dry, build the pieces back together using internal backing hardware along the split. Use hardware with slots to allow for inevitable movement. Don't even try to close the strip completely, just tighten it up, and consider the remaining cracks to be features of the piece.

    6. Fit the floating top and bottom pieces into rabbets in the log, preferably from a composite material (plywood). Attach only to one of the log halves, or if to both, be sure to attach with slots, to allow for movement.

    It's going to move after construction, but all tiki heads do. The cracks are part of the piece.

  9. #9
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    12,500 years of proof that wood cracks over time. Not much you can do to stop it. I had never heard of this woodworking. I was looking for ancient Egypt stuff this is three times older.
    Bill D.
    https://www.smithsonianmag.com/smart...ght-180977320/

  10. #10
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    How does sound get out of this log? You must loose a lot of the highs.

    As Steve suggests, make it a shell. The top and bottom are going to require some independence if they are going to be compatible with the constantly moving sides.

    Put feet under it and leave the bottom open. I'm imagining carved feet but plain rubber feet from McMaster Carr will work. Leave the top open too and put a loose tabletop on it. That'll protect the electronics from spilled drinks and the top from beer can rings.
    Last edited by Tom Bender; 05-22-2024 at 7:10 AM.

  11. #11
    Join Date
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    Quote Originally Posted by Tom Bender View Post
    How does sound get out of this log? You must loose a lot of the highs..
    OP states they are installing the amplifier in the carved log, not speakers.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  12. #12
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    Still need to vent it to get the heat out.
    Bill D

  13. #13
    thanks everyone for the replies.

    At this point I've given up on my initial strategy of split the log -> hollow it out -> screw it back together. I love the suggestions for filling in the gaps with ears, bamboo, etc, but the wood movement makes it nigh impossible for fixturing screws to hold. At worst they crack and the piece is no longer disassemblable without major surgery. For the record, my bandsaw worked pretty well for slicing the logs.

    Hollowing out the ends not only provides stability in the outer shell but also gives me more space to install the electronics; now I have the full 3 dimensional space of the cylinder instead of just one wall (pic attached). More and more it seems like an overall improvement.

    I generally carve the face first because I don't know how deep I need to relieve the carvings. (This may not have been clear in my first post, but I have several of these amps and they all have different tiki carvings - the one shown was just one example.) Plus I need to cut out holes for the tube sockets and ensure there's enough clearance in the carving for the tubes to be inserted and removed. Perhaps one day I'll be proficient enough to plan everything in advance. Anyway, only after the carving is complete can I know how thick the walls are allowed to be, keeping in mind the walls may be different thicknesses around the circumference to allow for hardware mounting, etc.

    After the carving I'll hog out most of the material with a Forstner bit, or perhaps a chainsaw.

    Question: what is the tool this guy is using to clean up the edges of this log? https://youtu.be/N4YoxQSjNRc?t=123. Some kind of heavy duty chisel?

    Removable top and bottom panels certainly make electronics installation easier. I'm toying with the idea of slicing a 1/4" veneer off the top before hollowing out and using it as a cover. The bottom will likely be a metal panel for mounting transformers. Both with have ventilation holes. I'm currently using rubber feet from Parts Express.

    earl_inside.jpg

  14. #14

  15. #15
    this is perfect, thank you!

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