What type of plywood?

[hon30critter]

cuyama

Much more time is spent ruminating over benchwork than it would take to build the thing, usually.

Byron:

How true! I believe I'm in that very situation right now!

Dave 

[hon30critter]

j. c.

don't remember is they can cut it the long way

Hi j.c.,

The big box stores won't cut anything narrower than 12". Their vertical saw tables can't safely handle narrower cuts.

Dave

[hon30critter]

doctorwayne

One disadvantage of plywood that's not been mentioned is getting it home.

Hi Wayne:

We have an Odyssey van but if I go the plywood route for framing I will have it ripped by the supplier. I have a circular saw and 8' long straight edge but I just can't handle the full sheets weight wise. I have considered having the 4x8 sheets ripped in half lengthwise and I will go that route if the cost to cut individual 4" strips is too high.

Dave

[rrinker]

hornblower

I live in Southern California and the dimensional lumber we get around here is absolute garbage.  No matter how carefully you pick through even the kiln dried stuff to find straight and untwisted boards, you've got nothing but pretzels a week after you get them home!  Thus, I went the ripped plywood route.  I used 1/2" hardwood plywood fomerly available from the big box home improvement stores (the currently available stuff is now as bad as the dimensional garbage).  I had to go to a specialty lumber yard to buy 1/2" Baltic Birch plywood (3x the price) in order to finish off the last section with similar quality plywood.  

I built open-grid fully-cantilevered benchwork using glue and mainly 18 gauge wire brads (only a few screws).  I bought the brad nailer from Harbor Freight for $20 and it will reliably shoot brads between 3/8" and 2" long.  I used 2" by 2" glue blocks to reinforce the corners and topped it with flat or cookie-cut 3/8" plywood glued to the benchwork.  Super strong and hasn't budged since I built it in my garage several years ago.  I have open spans as long as 13 feet, 24 inch deep cantilevers, and a freestanding two-deck peninsula double-cantilevered along a central backbone frame with no warping or sagging of any kind.  I did make the peninsula's backbone frame from kiln dried 2" by 4"s.  However, I first let them sit in my garage for several months to fully dry out.  I then picked out the ones that were still relatively straight and carefully ripped them down to a true 3" width using an extra long ripping fence to get them as straight as possible.  

 

 

 In the top pic - how did you attach the upper deck to the walls? The penninsula section is pretty self explanatory but what about along the existing walls?

                    --Randy

 

[IRONROOSTER]

UNCLEBUTCH

Every time I see a thread on benchwork ,I'm reminded of a day a lot of years ago, before I was serious obout MR.

I was working on a house and had to get in the basement.The homeowner led me down stairs and the first thing I saw, couldn't miss it, was a huge Lionel set up. It ran across the entire end of the basement 24/30 ft and came along the sides some. He had tunnels,buildings ect. was quite impressive. But what really caught my eye was that the entire thig was setting on sawhorses.He explained that in his rush to get trains running he juat grabed a couple of sawhorses and a sheet of plywood and started laying track. Thinking I'll build a proper table tomorrow,instead he just added more horses and plywood and never did get ''benchwork'' done.The thing looked great and ran flawlessly.I spent more time down there then I should have.

You can find your own moral to the story. Just  wanted to share it.

 

My middle son has filled his 12'x18' living room (he's a bachelor) with 2'x4' resin tables for his Lionel trains.  Quick and easy.  His "scenery" is green carpet squares.  He has lots of fun running trains.  I keep telling him he needs to build "real" benchwork, but he'd rather run trains.

Paul

[j. c.]

when the modular club went to plywood we had a sheet 1" plywood sheathing cut a local lows first 4 cuts were free rest were 25 cents a cut, don't remember is they can cut it the long way as we had them cut for 4 by 2 modules

[rs2mike]

hon30critter

 

 

speedybee

IMO it'd be best not to screw into the endgrain of either, and I don't see why you'd really need to?

 

 

How would you suggest attaching pieces at a 90 degree joint without screwing into the end grain of one of the pieces?

Dave

 

kraig pocket hole jig.  I love mine.  Got it from Lowes, probably online as well. They sell all sorts of jigs, come with the proper bits and screws to go along with them.  Built my cabinetry and shelving for my basement with it.  Loved how easy it was. 

[hornblower]

I live in Southern California and the dimensional lumber we get around here is absolute garbage.  No matter how carefully you pick through even the kiln dried stuff to find straight and untwisted boards, you've got nothing but pretzels a week after you get them home!  Thus, I went the ripped plywood route.  I used 1/2" hardwood plywood fomerly available from the big box home improvement stores (the currently available stuff is now as bad as the dimensional garbage).  I had to go to a specialty lumber yard to buy 1/2" Baltic Birch plywood (3x the price) in order to finish off the last section with similar quality plywood.  

I built open-grid fully-cantilevered benchwork using glue and mainly 18 gauge wire brads (only a few screws).  I bought the brad nailer from Harbor Freight for $20 and it will reliably shoot brads between 3/8" and 2" long.  I used 2" by 2" glue blocks to reinforce the corners and topped it with flat or cookie-cut 3/8" plywood glued to the benchwork.  Super strong and hasn't budged since I built it in my garage several years ago.  I have open spans as long as 13 feet, 24 inch deep cantilevers, and a freestanding two-deck peninsula double-cantilevered along a central backbone frame with no warping or sagging of any kind.  I did make the peninsula's backbone frame from kiln dried 2" by 4"s.  However, I first let them sit in my garage for several months to fully dry out.  I then picked out the ones that were still relatively straight and carefully ripped them down to a true 3" width using an extra long ripping fence to get them as straight as possible.  

[UNCLEBUTCH]

Every time I see a thread on benchwork ,I'm reminded of a day a lot of years ago, before I was serious obout MR.

I was working on a house and had to get in the basement.The homeowner led me down stairs and the first thing I saw, couldn't miss it, was a huge Lionel set up. It ran across the entire end of the basement 24/30 ft and came along the sides some. He had tunnels,buildings ect. was quite impressive. But what really caught my eye was that the entire thig was setting on sawhorses.He explained that in his rush to get trains running he juat grabed a couple of sawhorses and a sheet of plywood and started laying track. Thinking I'll build a proper table tomorrow,instead he just added more horses and plywood and never did get ''benchwork'' done.The thing looked great and ran flawlessly.I spent more time down there then I should have.

You can find your own moral to the story. Just  wanted to share it.

[rrinker]

I'm a good example - one corner of my previous layout had an odd step, hiding a support beam for the house, instead of a plain old 90 degree corner. Since I built most of it as standard sections, I had an odd shaped space to fill in. I pondered this for weeks, one weekend I just measured one last time and started cutting bits of wood and knocked it all out in a half hour.

 The problem, I think, is that there are many reliable ways to fasten wood together, and no matter what you come up with, you can find someone who swears by that method and an equal number who swear at it.

                    --Randy

 

[lifeontheranch]

cuyama

Much more time is spent ruminating over benchwork than it would take to build the thing, usually.

It's funny... because it's true.

[cuyama]

carl425

It also has to lock the joist against the girder to keep it from flopping over.  The higher your risers are, the more of an issue this may be.  If all you care about is moving sideways, you might as well just use nails.

Gravity does a pretty good job of keeping the joist against the L-girder flange. And after the second riser is secured to the subroadbed, there's not much sideways force on a single joist to "flop it over" -- and this is less and less as more risers are secured.

carl425

Another reason not to put screws into the edge of plywood.  It takes a very light touch to keep that screw from stripping out the hole in the plywood which will often make the screw difficult if not impossible to remove (with a screwdriver anyway).  This would hardly be a case of "easy to change". Screws into the edges of plywood is bad practice.  If you got away with it, consider yourself lucky.

I've helped build L-grid benchwork for a couple of layouts using "boards" ripped from quality ply. The issues you're mentioning never arose. I guess they could in theory, but it seems unlikely.

Stick lumber is fine (if you can find straight pieces). Ripped plywood is fine (if you start with good quality). Much more time is spent ruminating over benchwork than it would take to build the thing, usually.

[carl425]

Bayfield Transfer Railway

The only purpose of the screws on the joists is to keep the joists from moving sideways.

It also has to lock the joist against the girder to keep it from flopping over.  The higher your risers are, the more of an issue this may be.  If all you care about is moving sideways, you might as well just use nails.

Bayfield Transfer Railway

one of the design critera for L girder was to make it easy to change things

Another reason not to put screws into the edge of plywood.  It takes a very light touch to keep that screw from stripping out the hole in the plywood which will often make the screw difficult if not impossible to remove (with a screwdriver anyway).  This would hardly be a case of "easy to change".

Screws into the edges of plywood is bad practice.  If you got away with it, consider yourself lucky.

[Bayfield Transfer Railway]

I used plywood for the joists on my L girder benchwork.  The only purpose of the screws on the joists is to keep the joists from moving sideways.  The joists are held down on the L girders by gravity, so the fact that you're screwing into the side grain of the joist is irrelevant.

Also, re L girder, if you read Linn Wescott's original article on the subject, one of the design critera for L girder was to make it easy to change things, which is why it's a lot less fussy.

 

[doctorwayne]

One disadvantage of plywood that's not been mentioned is getting it home.  If you have a pick-up truck (or a friend with one), you're okay, or if you don't mind paying delivery charges, but if you have a small car, as do I, lumber is much easier to transport.
With the back seat folded down and the front passenger seat reclined, I can fit 12' pieces of lumber in the car, and carry even longer ones with the excess sticking out of the trunk.
I used "Select" pine for all my open grid benchwork.  It's supported on ordinary dimensional lumber, though, as I "accidentally"  ordered too much when I built this house.  In such use, it works fine and is a lot cheaper than the stuff used for the open grid top.

When I built the partial second level of the layout recently, I framed it with a mix of Select 1"x4" and 1"x2" in order to save weight, but I also needed plywood for the top.  I saved delivery charges (well, sorta) because I also order a bunch of metal roofing for my garage, which put the amount well over the required minimum for free delivery.
I also purchased all of the aforementioned lumber from a local lumberyard.  Their Select pine is much better quality than that offered by the big box places, and you can pick through to get exactly what you want.  When they didn't have enough 1"x2" in the lengths I wanted, they ripped more from larger stock, at no additional cost.

I've used some L-girder in a previous layout, but find open grid to be much stronger and more resistant to skewing, especially if you need to move it, as I did.  Pretty well all of the lower level of my layout was built on risers, and there are elevation changes in track and scenery all over it.  The risers can be just about any type of wood that you have on-hand.
If you want to use plywood for framing, regular 3/4" firply, good-one-side, should be fine, unless it needs to look like furniture.
For my layout, the support structure (and the junk stored on it - most of it has a shelf below the layout, a few inches above the floor, of well-supported 3/8" plywood)  is no longer visible like this older view...

...because I've hidden it behind sliding doors or lift-off panels of Masonite (delivered with the plywood and steel roofing)....

Here's some of the still-exposed open grid, with a selection of risers...mostly scrap left-over from house and layout construction:

Wayne

[carl425]

hon30critter

However, the more I think about it, the 'L' girder method seems to be much easier to do and will allow for any elevation changes much better. There is certainly much less cutting and fitting to do and angled joints won't require complex calculations to get the joint to fit properly.

Yeah but, in L-girder you attach the joists to the girders by running a screw up through the girder flange into the edge of the joist.  This works fine with dimensional lumber because only the end grain is bad for screws.  In the case of plywood, all edges are equally bad for screws.  Plywood strips IMO would not be acceptable for joists in a traditional L-girder.

And BTW, 1x3's are fine for benchwork unless you need really long spans. 1x4's are overkill.  Here's the chart from the original L-girder article.

	Span	Overhang
1 x 2	29	9
1 x 3	54	18
1 x 2 L	72	24
1 x 4	90	30
1 x 3 L	114	38
1 x 4 L	156	52

[richhotrain]

hon30critter

What would you use for corner blocks? The suggestion was made to use 2x2s but I'd be concerned about them splitting since they would be less than 4" long. I guess if I pre-drill them that would not be an issue?

Dave, you can buy wood corner blocks on the cheap. Poplar is used for cabinet making, and it is plenty strong, no fear of splitting.  Just Google 'wood corner blocks'.

Rich

[hon30critter]

I just did a comparison between the amount of wood required to build 'L' girder benchwork vs a simple box frame and the numbers came out the same. I guess that shouldn't be suprizing since both methods cover the same area. However, the more I think about it, the 'L' girder method seems to be much easier to do and will allow for any elevation changes much better. There is certainly much less cutting and fitting to do and angled joints won't require complex calculations to get the joint to fit properly.

Up until now I couldn't see the advantages of 'L' girder construction but the light has finally dawned! Darn I'm slow sometimes!!! I've been working on this for more than 10 years!!! (To be fair to myself, I've only started to design the benchwork in the last few months).

(Slow) Dave

[selector]

5/8" G1S (or "good on one side) plywood is plenty strong, has that nice one side smooth that is mostly knot free, is cheaper and lighter than 3/4", and can be ripped to precisely the same dimensions you need and still be stronger than you need.

For legs, I always use 1X2 spruce.  I buy it in the 10' lengths.  I place the top end up tight against a corner of the 1X4 frame outer (and by 1X4 I mean spruce or ply...either one), and then 'cap' the top of the leg.  This forms an effective and strong joint, although the 1X2 still needs diagonal bracing.

What I mean by cap is that I cut a 4" length of the same 1X2 as the leg, and place it outside the leg so that it is flush across both of them.  They both lie 'flat' so to speak.  Then I cut another 4" cap that is of 1X4 so that it caps, or covers, both of the snugged items, the leg top and the small block to its outside.  I drive several screws, always piloting first in softwoods, to make it all tight and rigid.

You'll find that 5/8" G1S will do everything you need it to do.  For what it's worth, on my last layout I built it all out of 1/2" exterior grade plywood, roughish stuff, including all my cookie-cutter roadbed.  It worked just fine, including in my large covered helix.

[Bayfield Transfer Railway]

Also, honesty compels me to admit that the one drawback to plywood is it is MUCH heavier.  Not a problem if it's not a portable layout, but you'll want good strong clamps to hold things during building.  I found I could use the "quick clamps" with pine but for plywood I needed honest to Pete C-clamps.

 

[Bayfield Transfer Railway]

hon30critter

Hi Michael:

How did you do your 90 degree joints?

Thanks

Dave

 

 

I used 2x2 s for legs, so I had a lot of 2x2 blocks and they worked fine.
I used sheetrock screws rather than wood screws. Have a second drill handy for a pilot hole. You don't need a full size full depth pilot hole, just a 1/16 hole about 1/4" deep was plenty.  Sheetrock screws are cheap and are very, very sharp so they're easy to drive.

The reason I don't recommend cheap plywood is that if there is a void in the second ply you can crush the outer ply.  Ask me how I know.

[hon30critter]

Thanks everyone. Lots of things to consider.

Just to clarify a couple of points, these are the things I decided right from the start to do:

- I have always planned on pre-drilling the holes regardless of the material. I have a double ended bit that does both the drilling with the countersunk hole at the surface, and it holds the screwdriver bit in the other end. Drill the hole, pop the bit out (its magnetic) and turn it 180 degrees, and drive the screw in. It will hold whatever type of screwdriver bit is needed.

- I also intend to glue the joints, again, regardless of material.

- cutting the strips myself is a non-starter. My back won't let me handle the weight of a 3/4 x 4 x 8 sheet of plywood. Doing the benchwork top surface will be bad enough with 1/2" ply. I'm trying to plan things so I can use 4 x 4 sheets on top.

What I haven't decided yet is whether to go with 'L' girder construction or just a flat box style. 'L' girder construction is attractive partly because there are a couple of depressed and elevated areas where 'L' girders with cross beams on top of them might make those areas easier to build.

Anyhow, please keep the suggestions coming.

Thanks,

Dave

[lifeontheranch]

Another vote for plywood although I don't think cabinet grade is warranted. Common 5 ply hardwood plywood works very well. I used the 3/4" birch sold at big box stores for $30-$40 a sheet for both my benchwork and sub-roadbed. Benchwork has been up for a little over 4 years, sub-roadbed in place for 3 years with no observable change. No track is kinking, no odd gaps have appeared, no warpage or sagging. Even the leftover strips of plywood laying in the shop bin for 3 years are still straight and flat. Can't say that about any of the stick lumber in the same pile.

Plywood grain runs perpendicular to the adjoining layer which makes it much more resistant to dimensional change than solid soft wood. Model trains and scenery don't weigh very much so strength is not a worry. Dimensional stability is the bigger issue. Hardwood plywood wins over stick wood in this measure.

Two important differences between plywood grades are the number and size of voids between the plys and the outer veneer thickness. Often the real difference between a $30 sheet of plywood and a $90 sheet of plywood. Veneer thickness is a cabinetmaker's concern, not important for benchwork. Minimum voids is important for benchwork as it affects screw holding. Better quality plywood has fewer and smaller voids. Stick lumber has no voids but does have knots and sapwood.

I suppose it varies with location, but here the price is pretty much a wash when comparing decent quality 3/4" ripped to 3-1/2" vs 1by clear stick lumber. You do need the ability to rip it yourself. Otherwise, paying someone could make plywood more expensive than stick wood. A table saw is ideal but if you had one you would probably would never have posted the question. A circular saw and a clamped straightedge can be used with success. Common angle steel or aluminum make a good straightedge.

End grain fastening in plywood is horribly weak and tends to distort the plys. Don't bother. The Kreg pocket screws mentioned earlier work very well. Blocking is also a popular and plenty strong method although it encroaches a little on the underside space. You can also use nailing plates and screws if you want easy to modify benchwork.

Stick lumber has the advantage in that you just buy it, cut it to length, and end fasten together. Very easy especially if your woodworking tool selection is limited. Plywood offers stronger straighter construction quality but does require more work and tooling on your part.

 

[7j43k]

Dave,

When I've used the 2x2's, it's not been as short as 4"--more 5" and 6".  I don't think it would make much difference.  BUT.  You absolutely need to drill a pilot hole. I use flat head wood screws, and I have an all-in-one drill that does the true pilot, the clearance for the shank, and the countersink.  If you're still worried about the wood splitting (not unreasonable), put a clamp or two  across the 2x2 at 90 degrees to help avoid that.  I've been known to.

I expect you'll be needing clamps, by the way, to hold things in alignment while you drill.  Crooked sucks.

So you're likely to have a whole forest of clamps at a joint as you work.  Ugly.  But the alternative is worse.  And, of course, you remove them when you're done.

I always get kiln dried clear fir.  I don't use much, so the cost is minimal.  But since it's "flawless", I can just keep chopping off pieces.  And it's stable.

I do mostly Free-mo.  We build LOTS of modules.  The sides and ends are 6" high.  The smart move is to add a plywood top, but some people do use foam only.  At first.  Anyway, all the modules I've seen use plywood sides rather than plank.  I use 3/4" AC interior ply, and am happy with it.  Other folks use fancier stuff.  Baltic birch 13 ply comes to mind.

Ed

[rrinker]

 I am strongly leaning toward using plywood instead of dimensional lumber when I start my next layout, for many reason, but cost and stability are the two big ones.

 The nice thing about using 2x2 nailing blocks, evn less than perfect 2x2's can be used (which is good because last time, I could never find even ONE that wasn't twisted to some extent) because you are cutting them down to short lengths. Splitting shouldn;t be a problem - I used the same sort of thing in the legs of my last layout - the legs were 1x3 and 1x4 in an L with a short section of 2x2 at the bottom drilled out for adjustable feet. 2 screws in each of 2 faces, plus a larger hole drilled up along the length and none of them split. I did predrill the holes on the faces, through both the 1x and the 2x2. To speed things up since this next layout will be MUCH larger, I'm considering getting a nail gun and using nails and glue instead of screws to attach the nailing blocks. It's the glue that does the real holding, properly applied it's stronger than the wood. If you've seen any of the newer layout builds on MRVP, they often use a nail gun to hold parts in place after applying glue.

 My other option would be to go overboard and make it all out of 2x4s which even the good ones are cheaper than a good 1x4 and the higher quality ones usually have a lot of straight pieces available - it's what I built my new workbench out of. Seems quite overkill though sonsidering most of the new layout will be able to cantilever out from the walls with very few legs.

                                      --Randy

 

[rrebell]

Use 1x4s, much easier and you can get nice 1x4s for fairly cheap. Knot holes don't always mater as with warp. I bought some 1x4s with a slight warp  in 8' but since I needed a 4' and two at 22 1/2", no problem, as far as knots go depends on where they are and the type, if you plan a little many times they end up in the scape.

[dknelson]

I have built some tables and benchwork using the ripped plywood to make both the L shaped legs but also the framing and joists (and the table top).  I used very ordinary quality 5/8" plywood.  I did indeed screw into the exposed end of the plywood both for the legs and the table framing and have had no problems with the joint giving way, even though two of the tables carry a considerable load (an artist's kiln in one case).  I was fairly lavish with the screws.  Jim Hediger had suggested this technique years ago in MR and it worked fine for me, with no need to go with furniture quality plywood (although I am sure that would LOOK much nicer).  I went with what I had on hand.  It did however have the virtue of being reasonably flat so maybe I should not call it "very ordinary quality"

Dave Nelson

[SouthPenn]

I was spiking down some rail and I couldn't get the spikes in. They would go through the ties, start into the plywood, and then stop and bend. Even trying to get track nails in with a small hammer was a problem. This was strange as I have spiked down rail in other section of my layout without problems. Turns out the older sections of my layout were on plywood with the top layer of wood was about 3/16" thick. The newer section was on plywood that had a top layer about 1/16' or less. The spikes would go into the newer plywood's top layer and stop when it hit the glue layer. Drilling pilot holes for spikes is a pain.

The layer thickness might be a consideration depending how you are attaching things to it. 

[carl425]

hon30critter

How would you suggest attaching pieces at a 90 degree joint without screwing into the end grain of one of the pieces?

I bought one of these jigs and the screws made for them

It makes nice pocket holes for screws.  Results in a great joint.

[ROBERT PETRICK]

Whether you use expensive plywood, cheap plywood, common boards, select clear boards, old-growth fir, framing 2-by lumber, or whatever . . . if you're connecting with screws, just two words of advice: drill pilot holes. And use star-head screws. The six point bit drives much easier than the four point Philips head bit.

Robert