Are 1x2s too small?

I'm planning the benchwork for my model railroad. Up until now, I had used 1x4s spaced 24" apart to support my modules, but I'm looking at using an
open L-girder style of benchwork. The L-girders I plan on making will be entirely 1x2s, but I'm not sure if they'll be strong enough. The reason for 1x2s is they'll be cut from 2x4s, providing a much better chance of getting straight lumber than with 1x2s.
The yard will be a 5/8" piece of plywood supported by L girders on a 12"x12" grid. Do I need to beef this up? I am in an area where movement because of temperature and humidity is a factor. The layout will be in an occasionally air-conditioned but always heated building.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 01 Sep 2008 12:35:01 GMT, Puckdropper <puckdropper(at)yahoo(dot)com> wrote:

My tinplate layout is atop 1 x 2 L-girder construction. Horizontal boards across top of the L-girder are 1x3 and legs are 2x2. Gussets are 1/4" ply.
Atop this is 1/2" plywood with 1/2" homosote on top of that. Homosote was secured to plywood with panel adhesive.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@earthlink.net wrote in

How long have you had it like this? Have you noticed any movement or warping of the material?
Please understand that my questions are that of someone who's planning for the next 20 years. My biggest regret with the old layout is cheaping out on the plywood for the first module, and not joining the two pieces I had together properly. Ten years later (Wow!) I'm having trouble at the spliced area.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 01 Sep 2008 15:18:36 GMT, Puckdropper <puckdropper(at)yahoo(dot)com> wrote:

Good question and I covered those points in my draft but somehow I edited out the last 2 lines.
Framework was begun in 1997 and basic layout completed late 1998. There has been no warping or sagging but I do keep a dehumidifier on most of the time. Layout is basically on two 4 x 8s about 6 feet apart. Side frames are 1 x 3s with 1 x 2 L-girder attached. By separate e-mail, I'll attach one pix showing some of benchwork -- I never enclosed in the side areas, so please excuse all the storage boxes underneath.

I have no regrets as to construction but, alas, to save time and money I went with a "duck under" layout. 10 years later and older, I find it more and more difficult to "duck under" to get to main control panel even though bottom of layout is 30" from the floor. For casual running I just attach a spare transformer and operate from the outside. Good luck
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@earthlink.net wrote: > > I have no regrets as to construction but, alas, to save time and money I > went with a "duck under" layout. 10 years later and older, I find it > more and more difficult to "duck under" to get to main control panel > even though bottom of layout is 30" from the floor. For casual running I > just attach a spare transformer and operate from the outside. > Good luck
    I know what you mean about the "duck under", I believe I was wise when I made mine 44.5" from the floor. Yet there are still days when ...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@earthlink.net writes

My layout is tinplate (0 gauge) too, and the frame is 1 x 2 softwood, with a 1/4 inch ply top. May be a little thicker than 1/4 inch - 5 ply, anyway. The boards have been in use for about twenty years, for various different layouts, and are fine. The boards are not really strong enough to walk on, though.
Support below the boards, using 2 x 1 softwood, is at two foot centres. Legs are a mixture of 2 x 2 and 3 x 2 - whatever I happened to have available.
--
Graeme, Scotland

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes

I'm surprised that your 1/4" plywood doesn't sag between the 24" centered supports. I know that 3/4" sheeting is suggested for 24" roofing supports. My first layout was similar only I had plenty of 1x2s so I used them on 12" centers. I wouldn't have danced on that but wouldn't have felt too bad walking on it... gingerly. : )
As mentioned elsewhere in this thread, if one had plenty of 1x2s, I'd think the best route would be to build L-girders or even I-girders. Properly screwed & glued, those should be very strong.
dlm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Snow, etc. is a lot heavier than model trains...

--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
At 01 Sep 2008 12:35:01 GMT Puckdropper <puckdropper(at)yahoo(dot)com> wrote:

For H0 or N, this should be strong enough, esp. since the 2x4s you will be slicing up will likely be spruce, rather than the pine that 1x4s are normally made from -- spruce is a bit stronger and denser than pine.

What scale? 0 or 1? :) 5/8" plywood is pretty heavy duty for H0 and serious overkill for N. 1/4" or 3/8" is even rather heavy these days. 3/4" or 1" insulation foam (pink (Owens Corning) or blue (Dow and others)) is more than strong enough. 1x2s can support this easily, unless you plan on standing on your yard or are going to put a solid plaster mountain in the middle of your yard...

--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Well, I cut 4 2x4s up today. We'll see how fast they evaporate when I get in to making them in to structure. I hope they'll be strong enough to prevent warping. (On the woodworking group, we have a saying: Wood warps. Wood Warps. Wood WARPS. WOOD WARPS.)

It's HO... but the plywood was cheap because someone cut about a foot off of it.
The mountain is going to be next to the yard. Probably use foam for that...

Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
At 01 Sep 2008 15:38:01 GMT Puckdropper <puckdropper(at)yahoo(dot)com> wrote:

The problem is: 5/8" plywood is going to be *heavy* -- much heavier that your trains! You will need lots of support structure *just for the plywood itself*. You *could* just rip the plywood into 2" strips and use that for your L girders or other supports -- this might be a better use for it than bothering with the support structure you will need to support it -- the thing is the weight issue becomes accumulative: you need something strong and heavy to hold up the (thick and heavy) plywood, then you need something to support and brace the support "timbers", and strong legs under that... That is why the old school benchwork needed so much wood (eg 1x4s). Using modern materials (foam) and benchwork technology (L-girders) lets you use smaller wood, eg the 1x2s, since you don't need to support lots of *heavy* plywood. The trains themselves are very light (and have allways been so, at least H0 and N scale: mostly plastic cars and loco bodies) -- you don't really need 1" (or 3/4") thick girders -- 5/8" would probably be strong enough, esp. if it is plywood.

Well, if you have the foam (or are planing on getting some anyway), you might as well use the foam for your yard. Foam has an additional advantage, besides being light: it does NOT warp.

--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 01 Sep 2008 12:35:01 +0000, Puckdropper wrote:

As has been said here before, ditch the lumber and go with plywood. L-girders cut from plywood will be straighter and stronger. I'd use a hardwood plywood if the cost isn't exorbitant. HD occasionally has some that looks like birch or maple but is just marketed as "paint grade", "Redi-Panel", or some such meaningless name.
But yes, 1x2s would probably work unless you plan on climbing on the benchwork or otherwise subjecting it to heavy loads.
Whatever you use, seal it on all sides by wiping on a coat or two of shellac - Zinsser's SealCoat is one of the best.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Around us, it's birch. They simply call it "hardwood plywood" and sell it for $25 a sheet. Repairs have been made and such, but it's got the same grain as the birch they're selling for $40 a sheet.

I think I'll beef it up a little bit, then. Growing up with the possibility of moving once a year leads me to build for the stresses involved in moving to a new house.

I'll definately do that. I might just use paint, though, as I intend on painting the top of the layout anyway.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 02 Sep 2008 12:55:36 +0000, Puckdropper wrote:

Just a hint - latex paint is made to allow moisture through. Shellac (dewaxed) blocks moisture transfer better than any other common finish. Oil based paint is somewhere in between.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Puckdropper wrote:

big snip

The object with the 'Shellac' is 'waterproofing' -- most paints are porous to water vapor (humidity) ---- I.E. be sure you are getting what you need/ want.
Chuck D.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 01 Sep 2008 12:35:01 GMT, Puckdropper wrote:

As has been noted elsewhere, make the L-girders from plywood. It naturally resists warping due to the cross-grain glue laminated layers.

Whoa!! A 12x12 grid is WAYYYY overkill, not to mention getting more in the way of things underneath.
--
Steve

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'll probably use both plywood and 1x2s making the L girders. The plywood for choosyness of size, and the 1x2s because they'll work really nicely. No need to predrill if you're far enough from the edge.

After having some time to think, I guess 12"x12" would be overkill. (But isn't that what the grids on the track plan are for, though? lol) I'll still run my cross braces at 16", though at least initially. That'll give me plenty of support to screw up (pun) the top.
Puckdropper
--
If you're quiet, your teeth never touch your ankles.

To email me directly, send a message to puckdropper (at) fastmail.fm
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

entirely 1x2s, but I'm not sure if they'll be strong enough.<
This concept is from Lynn Wescott (MR editor) years ago (40 years?) and it works. For HO it's not a problem and I have always built this way. For O scale there (might) be a weight problem.

12"x12" grid. Do I need to beef this up? <
Typical yard is 1/2" ply and 1/2" homosote. I don't think you need a 12 x 12 grid for this but just L-girder on (probably) 18" centers. 12 inch centers if you want to stand on it <VBG>!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Slicing up 2x4s would be worth it if you get them for less. I'd rather slice them the other way and get some 1/2"x4". The thing here is that the vertical part of an L girder is used for the load bearing and the taller it is, the more solit it will be. 1x2s will do the job tho if you are not going to crawl on the layout. Another way is to use the 1x2 for the top and bottom of a I beam where the center is 1/8" plywood of about 4-6" wide. A little cut in the 1x2s will put the plywood in a nice glue joint for max strength.
-- Bob May
rmay at nethere.com http: slash /nav.to slash bobmay http: slash /bobmay dot astronomy.net
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I've used 1x2s in benchwork just fine. Built a Wall mounted setup using 2x2s, 1x2s exclusively. The raw materials came from a previous floor standing layout. keeps the weight down. Structure design matters.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.