Replies

1. 
   nikkiwood | May 25, 2007 06:11am | #1

   My suggestion is to use whatever joinery you favor for the plywood cab, then mitre the edging.

   Assuming the plywood edges will be covered, there really is no point in mitering the cab.

   ********************************************************
   "It is what we learn after we think we know it all, that counts."

   John Wooden 1910-

2. 
   oldusty | May 25, 2007 08:00am | #2

     Hi T-Bone ,

                An Eagle project is a very important step for any Scout . Please don't jeopardize your nephews project .

            The project is designed to be a demonstration of his leadership skills , he really does not have to do any hands on labor himself , rather be able to direct his crew or help on the project .

      So it's up to the Scout to get materials donated or otherwise try and secure what is needed and arrange and organize and otherwise manage the job .

     It's an opportunity and obligation for the young man to learn , research and understand enough about the project and all the aspects involved to direct others .

        It would be wonderful of you to teach him how to draw a plan and figure materials and a cut list , show him how , don't do it for him . He needs to know what fasteners will be used and where to use them .

     I understand if your limitations may keep you from some methods but think things through with the Boy .Your role should for support should be as an advisor .

                    your doing a great thing good luck

                                         dusty

3. 
   stantheman | May 26, 2007 01:02am | #3

   T-bone

   glued mitered joints won't be strong enough for a cabinet.  The end-grain to end-grain orientation is the weakest there is.  The stress of standing up itslef will want to push the sides outward, and there is little to resist.  With a trim or a facing, reinforced butt joints woudl be better(glue,  dowels or screws), but not much.  Take a look at a similar existing cabinet and copy how it was put together would be my suggestion

4. 
   joinerswork | May 26, 2007 03:01am | #4

   T-Bone,

   If possible, apply (with screws and glue) a 3/4" x 3/4" or larger, strip (or series of blocks) along the inside of one side of each mitered joint.  Upon assembly, screw and glue the strip to the mating side of the joint, after applying clamp pressure as needed to tightly close the joint.  A caul ( 2" x2" or so strip) might be helpful on the outside of each end of the case/ each side of the joint, to pull out any warp  as you clamp it together, until you can run the screws in.  Do you have enough clamps?   As others have suggested, the glued miter joint itself is fairly weak, the glue bond between the strip and each side of the joint is where the strength will be.  If you can design for it, a face frame on the front of the cabinet will hide the blocking, and unless it too is mitered, can add some strength ( mortise and tenon frame joinery).

    Talk your Eagle candidate into letting you "help" with the design.  We always taught our scouts that a BIG part of effective leadership is in being able to "utilise your resources"- that's you.  His job is to pull together the talent, organise the logistics, and inspire the gruntworkers, to make HIS vision become a reality--not to do all the work himself.

   Good luck to your nephew on his project,

   Ray (a former S'master)

    

5. 
   Dave45 | May 27, 2007 02:58am | #5

   T-Bone -

   I wouldn't try to miter the plywood casework.  Mitered joints are inherently weak and unless your saw is dialed in perfectly and your skills are top notch, you'll find out that ripping two long miters and having them come together perfectly would be more about luck than skill.

   I would recommend making the carcass with simple dados and rabbets, then adding 1/4" thick banding (with mitered corners) on the front.

   This free suggestion is provided courtesy of another Eagle Scout (class of '61) - lol

6. 
   sapwood | May 27, 2007 03:22am | #6

   I presume you are talking basic simple technique here. In such case, I'd suggest you give him the following options:
   1. biscuit reinforced joint
   2. reinforce with finish nails.... drive from the top and sides
   3. screws either countersunk or flush in lieu of nails
   4. a spline joint cut with the tablesaw

   Any of these methods are good. They may not be "fine" woodworking but they are sound. Use glue along the plywood edge in any case. For that matter, glue alone will be enough to hold on a small cabinet made of plywood.