Experiment with acetylated wood (Accoya)

Discussion in 'Luthier's Corner' started by TonH, Dec 26, 2012.


  1. TonH

    TonH

    Joined:
    Jan 26, 2011
    This is a build to experiment with acetylated wood.

    Accoya wood is normal wood that because of acetylation (a wood modification process with a strong vinegar) hardly absorbs any moisture anymore in the cell walls of its wood structure. This has improved dramatically it’s durability against rot, mold and insects etc. It is also the best dimensional stable wood in the world (will hardly warp, crack, etc.).

    For more information see: http://www.accoya.com

    It is interesting to find out what the chemical process will do with the sound. Therefore, this experiment with Accoya Alder.

    The pictures below show the blocks of wood (alder) that I got from the factory.

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    For a good comparison, I will build a bass which design is very similar to existing models. The placement of the pickup's will be classical.

    The shape of the body is a cross between a Jazz Bass, Jaguar Bass and Bass VI.

    The bass will get three pickup's. A jazz pickup at the bridge, a precision pickup in the usual position and a jazz pickup at the neck but closer to the neck than usual.

    Also, a control plate with 3 switches (one switch for each pickup) like a Jaguar. The "control plate" for the tone and volume control is of type "Mustang".

    The body will be painted 2 tone sunburst and get tortoise pickguard.

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    [​IMG][​IMG]

    On the pictures above you see the drawing of the body already on a piece of MDF. After drawing the body shape on the MDF, I can cut out a template.

    More to come...
  2. Beej

    Beej

    Joined:
    Feb 10, 2007
    Location:
    Canadia
    Fascinating. I've heard of this for a long time, but I was unaware of any suppliers. Even the old farts I apprenticed with many moons ago would pass it along that soaking a timber in vinegar would improve it's life and resistance to rot. I used to think it was crazy until I heard of acetylating as a process.

    Looking over these guys' website, there is a lot of the typical snake oil marketing rhetoric you see anywhere, but the scientific articles were interesting. They are reviews and white paper descriptors rather than peer-reviewed research, but at least there is enough detail to sort out some wheat from chaff.

    What I took from the articles is basically this:
    1. The process will reduce decayability of wood significantly
    2. In some woods, the process can increase Janka hardness by up to 30% (which ones and how much not so easy to find)
    3. MOR and MOE are not altered enough to make a statistically significant effect by the process however some workers report "improved dimensional stability".
    4. The process makes wood hydrophobic and hence aliphatic glues are not preferable (titebond and regular wood glues), however epoxy and polyurethanes seem to work well (ironic as PU glue needs a wetted surface to work better!)

    Where did you source the lumber?
  3. TonH

    TonH

    Joined:
    Jan 26, 2011
    I got in contact with the factory/manufactor here in The Netherlands via their website.

    I asked them were I could buy the wood because I wanted to use it to make a (bass)guitar as an experiment.

    They called me to ask me what I needed. A few weeks later their relationship manager brought the wood over to my house.

    In return they want me to let them know how working with their product is compared to normal alder. And how the result sounds.

    The relationship manager told me the wood is used in harmonica's and does not need a (clear)coat like normal wood, because it is hydrophobic.
  4. grisezd

    grisezd Supporting Member

    Joined:
    Oct 14, 2009
    Location:
    Ohio
    Does the wood supplier recommend protection from the dust? I would imagine that the tool-heated chemical can be nasty!

    Great project, by the way.
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  6. TonH

    TonH

    Joined:
    Jan 26, 2011
    They claim it is non-toxic. I can't find any information about the necessity for protection against dust.

    I think that after the proces the wood is changed but there are no chemicals left.

    When I get a rash working on the wood I will let you know :), but I think it will be oke.
  7. younggun

    younggun Supporting Member

    Joined:
    Jul 19, 2008
    I see that the manufacturer gave you this piece...do you have any idea of the actual cost for the wood though? Is it significantly more expensive than untreated? Also, what are you going to use for the neck and fingerboard woods?
  8. HaMMerHeD

    HaMMerHeD

    Joined:
    May 20, 2005
    Location:
    Norman, OK
    It seems like an interesting product, but MAN that web site is ridiculous. There is more intentionally vague snake-oil marketing speech there than there is legitimate information. That silliness about "enabling nature" is just ridiculous.

    Regardless, I am looking forward to seeing this project take place. Are you planning to build an identical body out of untreated alder for the sake of comparison?
  9. Beej

    Beej

    Joined:
    Feb 10, 2007
    Location:
    Canadia
    The byproduct is basically just vinegar. Wood dust itself is a major health hazard though, so the typical precautions including a respirator are always warranted anyway. Ever seen a basic MSDS for "wood"? Blow ya mind... :)
  10. Beej

    Beej

    Joined:
    Feb 10, 2007
    Location:
    Canadia
    I agree with the estimation of the website, but try to find an honest marketer these days in any field!

    Regarding a comparison, that's also what I thought, but then again the difference between two basses built from the accoya lumber may be greater than the difference between the accoya and untreated alder. Only way to tell and get any measure of statistically significant meaning would be to build 40 of each and then conduct some research into their variability. But I'm sure no one wants to hear science, logic and reason from an old tonewood debunker like me...

    :D
  11. TonH

    TonH

    Joined:
    Jan 26, 2011
    For comparison I should build more than just one bass.
    But that would mean I should give up my day job. And I only have wood for one body.

    I don't think the shape of the body would be much of an influence. But the placement of the pickup's is. So that's why I thinking of the P-pickup and the J-pickup for the neck.

    For the neck I will use maple and for the fingerboard rosewood.

    If anyone got suggestions for a good comparison, please let me know.
  12. TonH

    TonH

    Joined:
    Jan 26, 2011
    Today I worked on the wood to make a body blank.

    I used the router to make a even surface to glue the pieces together.

    I felt like using normal alder.

    But the dust din't smell the same, it smelled like vinegar, acid like. :meh:
  13. TonH

    TonH

    Joined:
    Jan 26, 2011
    Here a picture of the two pieces glued together.

    I used PU-glue (poly urethane)

    [​IMG]
  14. sargebaker

    sargebaker

    Joined:
    May 2, 2004
    Location:
    Montreal QC CA
    Disclosures:
    owner/builder, ISLAND Instrument Mfg.
    ....Interesting product.
  15. TonH

    TonH

    Joined:
    Jan 26, 2011
    I has so time to continue with the project.

    In a music store that had to close down I could buy some Peavey tuners for just 20 euro's.

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    For the headstock I made a design that is a mix of the Peavey T40 headstock and a Fender Headstock.

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    The template for the body is ready, mix of Jazz bass, Jaguar bass and Bass VI.

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    There is enough wood in the body blank.

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    And a blank for the neck...

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    More to come...
  16. HaMMerHeD

    HaMMerHeD

    Joined:
    May 20, 2005
    Location:
    Norman, OK
    Indeed.

    I've gone through the legwork of figuring out how to setup a double-blind tonewood study. It's...expensive. Even limiting the scope of the study to common domestic american hardwoods used in the construction of solid-body electric bass guitar bodies, it'd still cost tens of thousands of dollars and take several months.

    Nonetheless, I've been thinking about putting together a proposal and applying for some grants to run the project.
  17. TonH

    TonH

    Joined:
    Jan 26, 2011
    This weekend I had some time to do some work on the bass.

    With the jigsaw I roughly cut out the body from the body blank.

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    I also roughly cut out the neck and headstock.

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    This is gonna be the fretboard.
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    And there was even time to make te template for the head stock.

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  18. TonH

    TonH

    Joined:
    Jan 26, 2011
    Update:

    The body is still to thick.

    With a self made rig and the router I bring down the thickness to 44mm (1.75 inch).


    The body sounds very bright whem you tap it!!!!!

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    I also found some time for the neck and headstock.

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  19. roberthabraken

    roberthabraken

    Joined:
    Jan 8, 2009
    Location:
    The Netherlands
    Very cool project Ton! I missed the start of it, glad I didn't miss the thread at all :smug:. Care to share the name of the supplier and the name of the glue you've used? I always find it hard to translate finishing products and glues to Dutch product names, types and brands. Is it something like "Bison Constructielijm" (construction glue) you've used? If so, they make up some silly names in Dutch don't you think?
  20. TonH

    TonH

    Joined:
    Jan 26, 2011
    Robert,

    Thanks!

    The glue I used is indeed the "Bison Constructielijm".

    It does the job :)

    Greetings,

    Ton
  21. TonH

    TonH

    Joined:
    Jan 26, 2011
    Now the neck is this far, it is time to glue the fretboard on top. It's good that I have so much clamps. ;)

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