I am thinking to use strips of plywood for the structure of benchwork.What do you think about that.
Plywood for layout benchwork is an excellent choice over standard dimensional lumber these days. You can choose between standard general purpose (usually sanded one or both sides) or birch plywood. The advantage of birch is that it has more plys (or layers) which add to it’s strength - although it is slightly more expensive. Both types of plywood will provide excellent stability if you live in a climate with large swings in humidity (such as the north eastern U.S. as I do) . However, you’ll need to rip the 4’ x 8’ sheets into 3 1/2 inch wide strips - a drawback if you don’t have access to a table saw or other good straight line sawing equipment. A home center will also do this for you for an additional fee.
Not a bad idea, although I would not use it to build L-girder construction. I would use it with supporting blocking for an outer frame, and perhaps for joists under subroadbed, or risers, or under foam. It would probably do well as legs to support the benchwork, although I would use triangular gussets for strength. That detracts from the overall appearance, unless you intend to place a decorative 1/4" mahogany plywood outside of the legs and outer framework to tidy up the layout’s outer perimeter a bit, as I have done.
I would not use anything less than 3/4" for supporting legs on my layouts, so unless you can get it really cheaply, or ripped out and discarded in reasonably good condition, it will be costly.
One drawback is that you cannot nail into the edge grain, it will split. It also likes to split with screws. but pilot holes usually help that. Be sure to use the new thin, self tapping screws. Old wood screws will cause problems no end. It is also harder to put screws into the side grain, but the self tapping ones work great. You will need a screw gun.
I switched to plywood, and will probably never go back to dimensional lumber. Rather then screws, I use air - driven nails.
Nick
Most all of your kitchen and lavatory cabinetry use plywood face to edge joints. The really high end stuff will use a groove to increase the glue surface, or else cleats or blocks to provide more rigidity, but many use simple edge to face butt joints and last for decades.
One trick is to avoid using this as a structural joint, unassisted. In a cabinet, the rear plywood facing keeps the plywood sides from wracking out of square, which would put stress on the corner joint.
We always pinned the joint with airnails to give just enough rigidity to the joint to allow the glue to set. Since we were working on high end homes, we also dadoed or routed a groove into the face, as described above.
For train benchwork, where appearance on the underside of the bench is not an issue, I’d either use a simple butt joint, if I could avoid wracking stresses through design, or else use a table saw to rip a bunch of 1" x 1" (3/4" x 3/4" actual dimensions) cleats, glue all adjoining surfaces of cleat and joint, and pin with nails crosswise, through one side into the other, and through each side into the cleat.
Ok it seems that you agree to use plywood.I was thinking to use 2,5" wide strips every 1,5 feet distance,with pilot holes and screws plus glue.For legs i"ll use standard lumber.
Plywood can warp easily. To keep it from happening, you will need to attach 2 pcs to form either an L or T shape or 3 pcs to make an I shape.
I built my benchwork using strips of scrap 1/2" plywood that was destined for the dumpster.
Using my tablesaw, I ripped pcs to 2 different widths- 2 3/4" and 1 1/2"
I cut a dado down the middle into the narrow pcs and then glued and air nailed them to the wider pcs making an I beam. The I beams end up the same size of 2x4’s you buy at the lumberyard.
I used the I beams for the benchwork of my layout the way people use L girder benchwork. I also used the I beams for the legs.
It’s only been a year since I built it, but it’s still very solid and I haven’t noticed any warping at all in my basement.
It would have been alot easier to use dimensional lumber- but also much more expensive.
If you have the tools, You should give plywood a try.
Craig