Table Top

[mabloodhound]

Why is it you suppose that all quality kitchen cabinet boxes are built from plywood?   Could it because it is the most stable material available?
Oh well, do what ever you want.

[jward]

please don't get me started on "quality" kitchen cabinets. lord knows i have delivered enough of them. i have picked up at at least 3 different factories, and delivered cabinets from probably a half dozen others that were delivered to our warehouse. i have seen them made out of particle board, plywood and solid wood.....and lord knows i have returned enough of them due to damage incurred in transit. plywood chips just like particle board, and all of them were put together in ways i wouldn't recommend. why? they do it to keep the cost down and increase profits, not because the materials are better. if you want something built right you have to get the amish to do it. they don't take shortcuts......

that said, most of us out there are going to find it a royal pain to try to cut down a sheet of plywood into useable beams, then work around its various flaws to build a nice table. pine on the other hand, can be worked with tools most of us  have around the house. and held together with common screws. i built my current layout using a power dril and a jigsaw. i could have built it with all hand tools, and have done so in the past. and if you read the original poster's description of the problem, it was the plywood that warped, not the table frame.  so evidently the plywood wasn't as dimensionally stable as was claimed. in fact, the simple and workable solution is not to build a complicated table out of the same material that warped in the first place, but to retain the table frame which DIDN'T warp, and use it's sturdiness to take the warp out of the plywood by better securing the plywood to the table frame.....

this method has been proven over the years, it has stood the test of time under various conditions. and not only in my own experience, but in the experience of countless model railroaders over the years. it is the method most often referred to for model railroad benchwork in books..... it can be easily built in an afternoon, from common off the shelf materials by anybody without needing woodworking skills....

[Jim Banner]

Jim-

I like your idea of edging a 4x8 with 1x2s on their sides to widen the train table. Could one then perhaps use 2x2s or 2x3s to frame the table with half of the 2" under the plywood and half under the 1x2s to further reinforce the side piece joints? I mention this because I think that two-by material under the joints would be good reinforcement but I wouldn't want to see something get as heavy as 2x4s would make it.
      -- D

That sounds like a good plan, especially if, like me, the builder wants to be able to crawl around on the table if need be.

The 0n30 layout I mentioned before had to be light weight for one old guy to move the sections but strong enough to stand up to the rigors of transportation.  My solution was to frame it with 1-1/4" x 2-1/2" box beams made of 1/8" and 1/4" Baltic Birch plywood.  To reduce their weight and increase their strength, the 1/4" sides were drilled with 1-3/4" holes every 3" which incidentally made the beams a great place to run the wiring.  A five foot length of this box beam, supported at the ends, easily held 100 kilograms (220 pounds) at its center .  I used these box beams on 12" centers both ways, in a grid, that supports the 1-1/2" Styrofoam top directly.  Total weight of each 4' x 5' section, before adding track and scenery, was less than 15 pounds.  Cutting and gluing all of the many little pieces was quite time consuming.

Our modelling group also uses light weight construction for our large scale portable layout.  Each section of that layout is 2' x 4' and consists simply of a piece of 1-1/2" Styrofoam framed with 1-5/8" wide strips of 3/4" plywood, either hardwood or Canadian Fir.  The bottom of each of these tables is covered with 1/8" hardboard which both protects the Styrofoam during shipping and provides an additional stress member to help support the table.  The track is laid on top of an inverted U-channel made of 1/4" hardwood plywood and the inside of that channel contains all the wiring.  At present, we have 51 of these tables and they stand up quite nicely to the heavy G-scale locomotives and trains we run on them.  It sounds crazy, and when I designed it in 1994, even I thought I was nuts.  But the numbers worked and so do the tables.

Jim

[jsmvmd]

Howdy,

What do you all think of the video building technique shown in "The World's Greatest Hobby" included with the track pack ?  Looks pretty complete to me.

Best Wishes,

Jack

[pjsdad]

I'd say you got some really low grade plywood if it bowed that much.

Try it again and splurge on the $30+ premium stuff and it wont go anywhere.