plywood for grid benchwork

[kchronister]

Has anyone here used plywood for benchwork grid instead of (e.g.) 1x4's. I've heard that ripping plywood sheets down to appropriate width (i.e. 3.5") strips of 8' length yields equally strong, flatter, straighter "1x4" lumber than buying pine boards. I do know the pine invariably has warp, woof and all that nastiness (yes, even properly dried good quality lumber bought from a real lumberyard - just less so than your stanard Home Depot "premium" pine).

Thoughts? Experience? Just from having worked with both materials, I'm leaning toward the plywood 1x4's at the moment...

Kris

 

[MasonJar]

Kris,

My modular group (www.hotrak.ca) now recommends 3/4" paintgrade ply over dimensional pine (even clear pine) for all applications in module building. This includes, sides, ends, gussets and cross-bracing (when needed). The only thing we use dimension stuff for is 2x2 legs. We put adjustable feet on the end so a bit of twisting or warping does not matter.

The pine is ripped to 4" (1/2" more than a standard 1x4) but the weight is really no greater. I think that you will find that the cost - even with paintgrade ply - is no more than dimensional lumber.


Andrew

 

[Doc Holliday]

Kris,
If you have the means to rip the plywood , go for it. Not only is it stronger, I found it to be cheaper. I cut 3/4" plywood into 3.5' strips and glued/screwed them into "L"s for legs. My layout is an approximate 8' x 11' "L" shape, 4' deep (don't make yours this deep, the reach is way too much). I ran the same strips at 16" on center and used 1/2" plywood on top. For reasons I won't go into here, I found out it could easily hold my weight (300#).

Doc

 

[shaygetz]

There was an article in RMC on using OSB (oriented strand or "wafer board) this same way. I would use the plywood myself (easy enough said as I have a tablesaw :thumb: ) as it is not affected by humidity as much and it would be as strong as the cleanest grade pine. Thanks for reminding me of this as my layout room is coming a closer reality by the day.

 

[ak-milw]

I have used both, mainly because I had some plywood laying around and have a table saw. I have not noticed any difference in the pine boards or the plywood, both are strong and have not warped yet. I built open box grid with cross supports on 1 ft. centers, then glued 1 1/5" foamboard on top with no plywood underneath. I haven't tried climbing on it yet but I can lean my weight on it with no problem. The shelf is 2' wide and 14' long.

 

[kchronister]

Thanks for all the feedback, everyone. I do have a radial arm saw that can rip the sheets down (with Mrs. C's kind help), so will probably give this a shot. I'm working on a 27x28 layout which has quite a lot of lumber involved. So anything I can do to ensure bulletproof benchwork is a plus...

 

[KCS]

Boy, I'd give both my arms and legs for a 27x28 layout and a place to put it but then I would have to operate it with my teeth. Never used it but I hear ash wood is good for layouts because it's light weight but yet just as durible. Problem I here is that it has a higher cost.

 

[MasonJar]

Ash is very strong, and straight-grained. It is easy to (steam) bend, and retains some flexibility as well. If you need to make a dog sled, or snowshoes, use ash...

Andrew

 

[Ray Marinaccio]

I used 3/4" plywood strips for the current HO layout I am building.
I clamped a piece of angle iron to my circular saw at 3 1/2 " from the blade and cut the strips off the sheet of plywood.
The strips are joined with 2x2x3 1/2" blocks that are glued and screwed together.
I built this one with 1' square gridwork and glued 2" foam on top with no underlay. It is extremely strong.

 

[kchronister]

Wow! nice!

One question for the gang: The three layouts I've built prior have all been - I believe - overbuilt in a big way. All could certainly hold me (275 lbs) standing on them, and none really needed to be able to do so... All used 1x6 lumber around the perimeter and had 1' grids of 1x4's. Sections were either open-grid with risers and cookie-cutter roadbed, or 1/2" plywood over the grid (if it was a fully flat area).

I'm really debating backing off that. It was very heavy, used a lot of wood, and just didn't need to be as strong as it was. With the fourth layout, experiences leads me to be more worried about stability (i.e. not warping, shifting, bending or rippling) than I am about sheer strength. In some ways, I get the feeling that MORE wood is just more to warp or twist, and less wood (especially if it's manufactured plywood or OSB) will reduce potential problems.

I'm thinking of either making the grid squares bigger (18"?) if using 1x4's, or backing down to something like 1x2 for the grid... Most of my layout will be 12-24" width only, with some wider areas (peninsulas) ranging from 3-4' widths. The only part of the layout 5' wide is a flat yard area that will have plywood over the grid... I'm sticking with hardshell scenery rather than foam, mostly because I know it and am comfortable with it - the point being there's not gonna be any 'heavy' stuff sitting on here. I'm not using real rocks or even massive rock castings. I'd guesstimate that what was on top of the benchwork in my last layouts weighed maybe 5% of what the benchwork itself weighed, if even that. This just seems like immense overbuilding to me.

Any thoughts?

 

[Ray Marinaccio]

I think that a 16" or 18" grid would be fine if you have a substantial sub roadbed. Such as plywood or foam over the whole benchwork.
Extra cross bracing may be needed for attaching risers when using Cookie cutter sub roadbed .
If your benchwork will be only 3'-4' you could use the same construction methods as modular layout modules, only longer sections.

 

[MasonJar]

I would go to 16" as it is "compatible" with standard 4 and 8 foot lengths that material usually comes in.

I would highly recommend you look at the foam (pink or blue extruded) as part of the benchwork and scenery. It is not difficult to work with, and beats hauling plywood, plaster, and whatever else down to the basement. 2-inch foam will not need support closer than 16", and is in fact fine across 2 feet (the depth of most of the www.hotrak.ca modules we have at the club.

Andrew

 

[Doc Holliday]

Kris,
I agree that many of us over-build our bench work, especially if it is a 2' wide around-the-room shelf type layout or similar. If I rebuilt to this type, I'd use 3.5" plywoood strips under 2" foam. I'd stay away from 1x2s for anything other than diagonal bracing or vertical risers though. In my experience a 1x2 just doesn't have enough cross-section to hold screws or prevent bending. I built mine more stout to provide shear strenght so I can roll the whole thing out from the wall to get behind it to work on the back side because I can't possibly reach it from the front and don't have enough room to leave it in the middle of the floor all the time as a walk-around layout.

Post some pics of what you end up with.
Doc

 

[pgandw]

My problem with plywood in place of lumber is the difficulty in successfully long-term fastening anything to the edge, even on 3/4" thick stock. If I use plywood where I know I will be fastening into the edge, I generally will edge it with some small dimensional lumber, using a glued lap or tongue-and-groove joint, with the lap or groove being done on the dimensional lumber. Butt joints at right angles reguire glue or screw blocks, as Ray showed. Of course the latter is true for dimensional lumber, too; you generally can't nail, screw, or glue into the end and expect any strength to the joint.

Unless you have a mounted table or cutoff saw to rip the plywood, or can get somebody to do it for you cheaply, I fail to see the savings over selecting reasonable quality dimensional lumber - especially for a smaller layout.

 

[kchronister]

Fred - There probably isn't any signfiicant savings - perhaps even with a saw that can rip it (which I have). For me, it's really not about savings though, but rather the greater stability of plywood/OSB versus dimensional lumber. Even in a climate controlled and rather stable humidity basement I had lots of warping and bending problems with clear pine boards...

As for your first point, I'm confused. You say the ability to join to the edge is your strike against it, but then admit dimensional lumber has about the same issue? Regardless (and I'm sure I'm simply misunderstanding you), if I were butt-joining to a 3/4" width of anything, I'd glue it - always stronger than nails or screws - which makes it rather moot. If I used screws they would only be to hold it tight while the glue cured.

 

[MasonJar]

Fred...

You're missing the point - you use the project as an excuse to get yourself a table saw to rip the wood...!! :thumb:


Andrew

 

[stuart_canada]

i was just thinking that. you can get small 10 inche saw at home depot, ryobi brand for 100 us bucks, a bit more in canada, but they do have low end saws that will do the job quite well. I use my ryobi saw all the time and it does everything i want it to do and more.....was ripping 2x8s today worked fine

 

[pgandw]

:thumb: Thanks Andrew, I needed that! You guys are far more creative than I. Time for a trip to Home Depot and Orchard Supply for some male "bonding" and the tool crib!

 

[Glen Haasdyk]

I used 3/4" fir plywood for my benchwork grids, cut into 3" strips and but jointed using 2" screws:

Of course, fir ply isn't available anymore as far as I know (I got it from my father in law) But other plywood will work just as well.
These pictures are part of a thread that I wrote almost a year ago going from benchwork to track laying.

http://www.the-gauge.com/thread11669-benchwork-to-tracklaying.html