502,307 active members
5,781 visitors online
Register for free
Login
Results 1 to 5 of 5
  1. #1
    Registered
    Join Date
    Aug 2011
    Posts
    957

    Looking for low-shrink solid hardwood advice

    I am planning to build a pretty intricate wooden mechanism, not a clock but a combination lock for a chest. Of course I could use good quality plywood to avoid the inevitable shrink and expansion problem with humidity but for aesthetic reasons I would prefer nice solid hardwood.

    Can somebody give my a recommendation for a wood species that has proven to be good for clocks that is low shrink, reasonably hard, not splintering, machinable and obtainable in a well sorted hardwood lumber store? The parts will be rather small so it is O.K. if not cheap. I guess Teak and Padauk might qualify but I am not sure what else may be better. FWIW the parts will not be glued so no problem if oily.

    Thanks,

    JB
    Box Joint and Dovetail CAM software here: WWW.TAILMAKER.NET

  2. #2
    Registered
    Join Date
    Jun 2012
    Posts
    149
    Pressure casting with clear polyurethane would allow you to use any wood and not worry about shrinkage.

    Somewhere on this site should be the info you need for any wood species: Forest Products Laboratory - USDA Forest Service

  3. #3
    Registered
    Join Date
    Jul 2013
    Posts
    15
    Buy hard maple, and a pressure kit from www.packardwoodworks.com. Do it yourself, super easy


    Sent from my iPad using Tapatalk HD

  4. #4
    Registered
    Join Date
    Aug 2011
    Posts
    957
    Thanks guys, that sounds like it should work. I even have a good vacuum pump but did not think of vacuum impregnating the wood.

    The link examples were mostly for pen blanks but I guess I could do some 3/4" thick plates as well.

    I am wondering if I might have a chance stabilizing with thin epoxy resin, maybe when heated and really low viscosity? I still have a jug left over from another project.
    Box Joint and Dovetail CAM software here: WWW.TAILMAKER.NET

  5. #5
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Posts
    33797
    The problem with heating epoxy is that it will cure faster, especially if it's in a cup, or pot. As the curing reaction takes place, some epoxies can get hot enough to start a fire. You need to make sure you have a very slow setting epoxy.
    Depending on the wood species, most of the liquid will be drawn in through the end grain, and on larger sized pieces, you may not get enough penetration.

    The most stable wood will be wood that is quartersawn. Depending on the size of the parts, though, it may not make too much difference. Wood movement is measured as a percentage of growth or shrinkage, and for kiln dried hardwoods, it's typically going to be from 1%-5%. That's a very small amount for a small part. And if you live where's there's not a lot humidity most of the year, you might not see much movement at all.

    You might be better off choosing wood for it's strength, rather than stability. Depending on the application.
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

    JointCAM - CNC Dovetails & Box Joints
    http://www.g-forcecnc.com/jointcam.html

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)

Similar Threads

  1. Shrink-fit Tooling
    By jakemestre in forum Tormach Personal CNC Mill
    Replies: 18
    Last Post: 08-01-2018, 02:12 PM
  2. Need Advice: Machine for cutting 3/8 solid rod
    By BigChief in forum Uncategorised MetalWorking Machines
    Replies: 3
    Last Post: 05-31-2013, 04:53 AM
  3. Replies: 14
    Last Post: 05-01-2013, 01:39 AM
  4. Shrink FIT
    By Ashish B in forum Linear and Rotary Motion
    Replies: 24
    Last Post: 12-30-2010, 06:49 AM
  5. Shrink fit tooling
    By Dropout in forum General Metalwork Discussion
    Replies: 3
    Last Post: 06-08-2009, 02:23 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •