Table Top

[wmsuggs]

I need some advise. I used a sheet of 4 x 8 x 3/4 inch plywood for my layout. I also used 2 x 4's around the perimeter and across 2 feet on centers. The problem I am having is my plywood and 2 X's were straight when i picked it out at the lumber yard, but now my top has a bow in it. I really don't want to start over but if I need to OK. Is there anything I can do? I thought of using bridge piers that would give the appearance of a bridge but in fact my track would be level.

Thanks,

Wes

[CNE Runner]

Wes, if you got a straight 2x4 at one of the 'box stores' (or probably any other supplier0 you were extremely lucky! I spend most of my time, shopping for lumber, by looking the the most straight boards.

OK, more to the problem: Get rid of the 2x4s and use 1x4 lumber. I have found the L-girder construction (ala Model Railroader and Lynn Westcott) to be the best all-around type of benchwork support. There are numerous articles on this type of construction. Check out the Info Station on Model Railroader's website. You can purchase downloadable articles on many subjects at this location...one of which is benchwork construction.

Regards,
Ray

[wmsuggs]

Thanks for the info. I want my first layout to be right.

Wes

[jsmvmd]

Dear Friends,

Is not a 5' x 9' to be recommend to allow 22 inch curves ?  Seems to me that was much discussed on this forum several years ago.  Too, I believe a ping pong table is 5 x 9, is it not ?  That is for one who wishes a portable item.

Best Wishes,

Jack

[Jim Banner]

For those of us who like to live dangerously, 22" radius curves fit quite nicely on a 4' wide sheet, leaving about an inch between the edge of the road bed and oblivion.  For those a little less venturesome, it is possible to install a guard rail between the roadbed and the big cliff in places with a high risk of derailment, both at the ends and along the front.  To guard against "spillage" at the back of the layout, a backdrop is the perfect answer.

Another solution is to use 1x1 trim around your table, adding 1-1/2 extra inches to its width and giving a nice, splinter free edge to the layout.  For a little more insurance, use 1x2 as trim, applied flat ways using glue and 3" screws in drilled and counter sunk holes.Your 4' sheet has miraculously become 51 inches wide, a full 5" wider than the roadbed.  This allows room for trees/hedges/bushes between the rear track and backdrop and enough room on the front to lay a train over on its side without it falling to the floor.

While I really like Jack's ping pong table idea, sometimes we are forced to use tighter dimensions.  I am presently working on a 4' x 10' 0n30 portable show layout that has to fit in the back of a mini van.  So it is a loop with 22" radius curves with a single track folded dogbone inside the loop.  This works out to 18" curves and 4% grade in the helix, which in turn means running multiple small locomotives and/or geared locomotives to get the tonnage up the hill.  But hey, that is part of the fun of model railroading - overcoming obstacles by building railroads suited to our self imposed terrain.

Jim

[Doneldon]

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

[jward]

what i've done is similar to what jim described, but using 1x4 or 1x6 extensions along the side. rather than using 2x lumber for the frame to support these extensions, i used blocks made of 1x4 sawed diagonally to make a triangular bracket, which was screwed into the layout from the inside of the main frame.

[mabloodhound]

The 2x4's are the problem.   Boards can also give you a similar warping problem.
Use 3/4" plywood.   Buy a sheet of AC 3/4 (about $25) and rip it into 4" strips.   Use these instead of boards to build with.   They won't twist and warp like the new growth boards you get from the big box.   And the plywood won't change over time with humidity differences like boards.

[Johnson Bar Jeff]

While I really like Jack's ping pong table idea, sometimes we are forced to use tighter dimensions.  I am presently working on a 4' x 10' 0n30 portable show layout that has to fit in the back of a mini van.  So it is a loop with 22" radius curves with a single track folded dogbone inside the loop.  This works out to 18" curves and 4% grade in the helix, which in turn means running multiple small locomotives and/or geared locomotives to get the tonnage up the hill.  But hey, that is part of the fun of model railroading - overcoming obstacles by building railroads suited to our self imposed terrain.

Jim

Indeed. I once built a platform designed to fit under a twin bed; it was only 39 inches wide. I adapted a track plan from Kalmbach's Small Railroads You Can Build, using 15-inch radius curves on one end of the layout--I wasn't planning to run anything larger than a 4-4-0. For various reasons that railroad never got built. I ended up laying one loop of 18-inch radius curves with an inner loop of 15-inch radius curves, just so I could keep my locomotives in running order.

[wmsuggs]

Thanks for all the feed back. This is a great forum for new members who are just getting started in the hobby. I went by my local hobby shop today and picked up a bargain on two hopper cars that fit my theme.

Wes

[jward]

it would seem to me that unless you have access to a table saw (i don't) making side beams for your table from plywood would be much harder than using pine board. i also question how well screws would hold driven into the layers of laminate from the sides which you'd have to to to assemble a plywood frame. driving screws between the laminated layers might split the plywood. since the use of higher grade pine or spruce would eliminate warping, that in my opinion is the way to go. my dad and i have built tables this way for 35 years, and even under extreme conditions of humidity, warping has not been a problem. to be honest, i have seen alot more warping with plywood than with a properly constructed pine wood table.


which brings up a question for the original poster: is it the plywood or the 2x4 that has the warp in it? and is it objectionable to the point it affects the operation of your trains?

[wmsuggs]

It is the plywood that has bowed. It does not affect the operation of the train it just don't look as flat as i want. I used 2x4's turned up edge ways to pull most of the bow out. I agree that any fastner ran into the edge of plywood will split.

[jward]

you can often straighten out bowed plywood by sinking a couple of screws into the table frame in the area where it has bowed. the screws should pull the plywood down flat against the frame. and if you do this all around your layout, you can prevent further problems. i'd sink screws about every 12 inches over the whole layout, and 6 inches or less in the trouble area.

[Doneldon]

jward-

Properly-sized pilot holes will allow you to screw into the
edges of plywood without splitting the material. Other
possibilities for this constuction would be dowels or biscuits.
The biscuits, especially, would avoid splitting.
                                                                 -- D

[jward]

all in all it sounds like more trouble than it's worth.