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What type of plywood?

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Posted by betamax on Saturday, February 4, 2017 4:45 AM

hon30critter

 

 
ROBERT CASWELL
You are a Canadian.  Use Robertson screws.  Invented in Canada and the best to work with as they do not "torque out" like Philips screws

 

Robert:

Yup, Robertson it is! In fact, its hard to buy anything but Robertson screws for regular use here.

Dave

 

 

Good choice anyway...

I had to build some assembly stands at work for an experiment.  Basically the same as benchwork, a small box with internal bracing and a top panel, using plywood.

In some places the voids in the plywood were such that fastening it with screws would not work, as half the material was air.

I didn't use screws, as they may cause problems during the experiment, so everything was glued using LePage (Henkel) Pro carpenters glue.  It tacks quickly and holds things together while you clamp.  With a small box it wasn't a problem to get everything aligned, but after 30 minutes it was unbelievably solid.

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Posted by hon30critter on Friday, February 3, 2017 10:34 AM

ROBERT CASWELL
You are a Canadian.  Use Robertson screws.  Invented in Canada and the best to work with as they do not "torque out" like Philips screws

Robert:

Yup, Robertson it is! In fact, its hard to buy anything but Robertson screws for regular use here.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Friday, February 3, 2017 10:28 AM

Steve:

Thanks for the advice and the link. Very impressive work.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Friday, February 3, 2017 10:22 AM

wolfman06
I built my entire two level 30x30' layout with 3" x 3/4" plywood strips.

Mike:

What grade of plywood did you use?

Thanks

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by wolfman06 on Friday, February 3, 2017 7:02 AM

I built my entire two level 30x30' layout with 3" x 3/4" plywood strips.  I have a table saw and a plate joiner (biscuit joints). I also have an air powered nail gun (2 1/2" finish nails I think in this case). Open grid.  After cutting the biscuit pockets, it goes together quick with nails and glue. No pre-drilling. And strong enough to stand on.  No corner brackets needed. Traditional risers screwed to frame to support changes in elevation. Would definitely do it again the same way.  No issues with warped boards, knots, or splits. 

Mike

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Posted by Choops on Friday, February 3, 2017 6:23 AM

Did you have any trouble working between the angled joists? Others have suggested that having the joists too close together will cause problems if you need to work between them.

That is the best part about L-girder constrution the joists are screwd to the l girder from the bottom.  if you need to move one you unscrew it from the bottom and move it over.  The joists only need to be every 16 to 20 inches.

Steve

here is a link to my FB layout page.

https://www.facebook.com/steve.krass/media_set?set=a.10204608198199226.1073741830.1662755162&type=3

Modeling Union Pacific between Cheyenne and Laramie in 1957 (roughly)
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Posted by hon30critter on Friday, February 3, 2017 3:59 AM

Byron:

cuyama
Correct. As others are pointing out, it will create problems and offers no benefit.

The voice of experience!

Thanks,

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Friday, February 3, 2017 3:57 AM

Steve:

I have been thinking that L girder is a waste of time in the areas you mention since the sub roadbed will all be flat anyhow.

Your benchwork is very similar to what I had envisaged.

Did you have any trouble working between the angled joists? Others have suggested that having the joists too close together will cause problems if you need to work between them.

Please post some more pictures too if you will.

Thanks

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by ROBERT CASWELL on Thursday, February 2, 2017 11:02 PM

You are a Canadian.  Use Robertson screws.  Invented in Canada and the best to work with as they do not "torque out" like Philips screws which were actually designed to do that. #6 Robertson screws are best when going into end grain but I agree with another poster who suggested corner blocks to get away from end grain entirely.  The "L" girder style also described by another poster, though not called that in the post is an interesting alternative as it allows for undulating edges and easier terrain options.  It usually uses boards and no screws go into end grain.  There are alternatives and its all fun.

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Posted by CNSF on Thursday, February 2, 2017 5:08 PM

I can't speak for which is "best", but will simply share my own experience.  I chose box frame over L-girder for two reasons:

1) I wanted modules that could potentially be taken apart and reassembled (but now realize that'll never happen; if I move, it'll be easier to just start over)

2) box frame has a thinner profile; I have a multi-deck layout and wanted to maximize clearance between decks (saving just an inch or two on the upper deck especially is worth it)

I used cheap 1x2's from Rona for framing and 2x2's for legs (yes, I spent some quality time picking through the pile for the most straight-ish ones).  Over this I have laid 1" styrofoam as the scenery base.  It's probably been close to 10 years now since I completed construction and began operating and adding scenery & structures.  Results - no problems at all as long as I run a dehumidifier in the room (basement) during high humidity spells in summer (which is also good for the electronics).

Your results may vary.

One caveat - mine is an 'around the walls' bench-style layout, so I'm never required to stand on it.  I've leaned on it pretty heavily, though, with no issues.

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Posted by cuyama on Thursday, February 2, 2017 12:05 PM

hon30critter
Are you suggesting that I shouldn't have some of the joists on sharp angles to the girders as I have shown in the plan?

Correct. As others are pointing out, it will create problems and offers no benefit.

I believe that it was Linn Westcott who said of benchwork: "Build bridges, not tables." Bridges are mostly air. Keeping the joists perpendicular to the L-girders (and the aisles) for the most part allows for a broader span between them -- less material, same utility.

 

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Posted by Choops on Thursday, February 2, 2017 11:57 AM

Looking at your design.  I would build box frames along the two walls attached to the studs with angle supports.  I would simply use 1X4 for this.  for the two peninsulas I would use the L girder style framing to accomplist the gentle curves. use 1X4 for this also.

I think ripped plywood is overkill for benchwork.  However every design has different needs.  Dave Barrow uses it because he likes to rebuild and move sections around and wants a precision box to do that.  Hornblower used it for a specific peninsula situation that needed it. 

Anyway here is a pic of my benchwork.  My layout is a folded dogbone also.

https://scontent.xx.fbcdn.net/v/t1.0-9/15170898_10209744706528724_1670331933956695332_n.jpg?oh=7d52326fb6f945d5e463515135f3ee98&oe=59035810

If you need more pics just ask.

Steve

Modeling Union Pacific between Cheyenne and Laramie in 1957 (roughly)
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Posted by hon30critter on Thursday, February 2, 2017 11:44 AM

Thanks Mike. I'll look it up.

Dave

Edit:

I looked up the article. The author, Pelle Soeborg, uses minimal material, 1/2" ply and 1x2s. I'm just not comfortable doing things to a minimum. I want to be able to safely put my weight on the layout and I am a heavy guy.

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Thursday, February 2, 2017 11:42 AM

"You create narrow cavities that later will be difficult to work in with your hands and fitting undertrack equipment."

Ah ha! Eventually I would have discovered that as I was tearing the offending joists out!

Thanks Alan.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by mbinsewi on Thursday, February 2, 2017 10:48 AM

Dave,

While reading an article in the March, 2016 MR about sheet steel flat car loads, there is also quite an extensive article on benchwork, and the guy used plywood.

Just noticed it, and thought of your thread.

Mike.

EDIT:  Wow, top of page. I hope that doesn't have the same consequences as the diner!  Laugh 

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Posted by lifeontheranch on Thursday, February 2, 2017 7:45 AM

hon30critter

Are you suggesting that I shouldn't have some of the joists on sharp angles to the girders as I have shown in the plan?

You create narrow cavities that later will be difficult to work in with your hands and fitting undertrack equipment.

It is box, not L girder, but pareil pareil. Maybe it will give you some corner ideas:

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Posted by hon30critter on Wednesday, February 1, 2017 11:59 PM

cuyama
Most of the joists can still be perpendicular to the L-girders (or angle slightly)

Hi Byron:

Are you suggesting that I shouldn't have some of the joists on sharp angles to the girders as I have shown in the plan?

Thanks,

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by cuyama on Wednesday, February 1, 2017 11:42 PM

Most of the joists can still be perpendicular to the L-girders (or angle slightly) even if the edge of the layout curves. Easier to build, shorter joists.

At the river valley, they can parallel the watercourse on either side, perhaps.

Note that in spots, the risers can also come up from the L-girders themselves.

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Posted by hon30critter on Wednesday, February 1, 2017 11:39 PM

Alan:

Thank you for the detailed plywood grade explanation. Very helpful!

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Wednesday, February 1, 2017 11:34 PM

trainnut1250
Dave: Do you have a basic track plan and foot print for the layout space? That will drive the design of the benchwortk more than anything else...

Hi Guy:

Yes, I have a very detailed plan for the layout, which has been revised countless times by the way. I have two possible plans for the benchwork, one using a box frame and the other using L girder. The only areas where I'm still trying to figure things out design wise are the tops of the helicies and the river valley.

This is the track plan:

This is the preliminary plan for the L girder benchwork:

The room is 23.5' x 12' on one end and 8' on the other. There will be walls on all four sides. The north wall is the existing garage wall. The east side is a sectional garage door which I will put a wall in front of. The south and west sides will have walls with a couple of access doors in each of them so I can reach into the layout in the wide spots. The backdrop won't be seamless but I can live with that. There will be lower level staging.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by trainnut1250 on Wednesday, February 1, 2017 1:45 PM

Alan,

Thanks for the descriptions of plywood. Based on what you have written, I was using stain grade, not cabinet grade. Must have gotten some pieces on the low end of the QC scale. I was a bit perplexed by the voids in what was being called cabinet grade, but it makes sense now...

Hornblower: Wow...Excellent design and execution of benchwork. Looks great!!!

RE scared: Dave was making a joke...I don't think anyone who builds critters and the like is intimidated by benchwork.

Dave: Do you have a basic track plan and foot print for the layout space? That will drive the design of the benchwortk more than anything else...

 

Have fun,

 

Guy

 

see stuff at: the Willoughby Line Site

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Posted by hornblower on Wednesday, February 1, 2017 12:51 PM

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

 

 

Randy

Both the upper and lower decks are attached to the existing wall studs in the same way.  I used two 5" wide strips of 1/2" plywood doubled up for attaching to the walls.  However, I first located the positions of the cantilever ribs and glued/screwed 2" by 4" glue blocks to the wall mounting strips prior to attaching them to the walls.  I then used large fender washers and 2 1/2" long deck screws to attach these strips to the wall studs.  The doubled plywood strips easily resist the twisting load of the cantilever and the fender washers ensure that none of the mounting screws will pull through the plywood.  I then attached the cantilever ribs to the glue blocks using wood glue and wire brads.  The fascia panels (also 1/2" plywood) are structural members providing span strength to the cantilever assembly.  Except for the central backbone of the main peninsula and just three additional legs supporting the two helix assemblies, there are no other legs under the rest of the 10' by 19' layout.  This provides 30" high and 24" deep clear storage space under almost the entire length of the layout.

The real construction challenge was the main peninsula.  As the layout is located in my garage, I needed to make sure that the sectional garage door could still be opened.  This meant that at least six feet of the peninsula had to be truly freestanding so that the sectional door could clear the top of the peninsula.  While the far end of the peninsula structure is attached to a storage loft at the top, the door end of the penisula is only attached to the floor. Once all of the peninsula framing was complete and the layout decks attached, the peninsula was quite sturdy aside from a bit of flexing towards the door end.  However, this flexing was totally eliminated by gluing 1/4" drywall backdrop panels to the central backbone framing.  It is amazing how the added shear strength of the drywall backdrops made the peninsula as rock solid as the remainder of the benchwork.

When I built the benchwork, I purposely included a 1/8" crown in the middle of the longest spans to compensate for any settling I anticipated would eventually occur.  The layout has been up for almost 10 years now and all of the 1/8" crowns still exist.  I guess my original engineering of the structure paid off!

Hornblower

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Posted by UNCLEBUTCH on Wednesday, February 1, 2017 9:06 AM

hon30critter
Guy, you're scaring me

 MRing is a hobby,,ment to be fun.There are no police to arrest and fine you for doing a part wrong, if its works for you, it can't be wrong.

If you allow any part of the hobby to stress or scare you, perhaps you should reconsider your choice of hobbies

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Posted by lifeontheranch on Wednesday, February 1, 2017 9:00 AM

Should you decide 3/4" plywood:

'Cabinet grade' plywood costs around $100 a sheet. Not sold at big box stores or stocked by many lumber yards. Completely void free. 13 hardwood plys. Thick face veneers. Non-stitched single face veneer one or both sides, sometimes small plug back. A/A or A/B. No quality concerns. Benchwork using genuine cabinet grade would be insanely expensive but beautiful.

'Stain grade' plywood costs around $30-$40 a sheet. This is what the big box stores sell and what cabinet makers sometimes use when the application has no exposed edges. Often mistakenly called cabinet grade. Some small voids. Typically 5-7 plys, sometimes hardwood sometimes MDF or other pressed product. A/B or A/BB. Some quality variance, inspect before buying. Good for benchwork.

'Utility grade' is common softwood plywood and comes in many varieties and price points. Rarely more than 5 ply. Expect voids, large plugs, knots. B/BB or BB. Wide quality variance. What most people think of as plywood. Low cost benchwork.

'Sheathing grade' is softwood plywood widely used in construction. Non-plugged. Non-sanded. Face quality unimportant. Cracks acceptable. C/D. Exterior grade glue. Not suitable for benchwork.

"Marine, aircraft, and pressure treated' are special application plywoods. Not applicable to model railroading.

Avoid sheets from the top or bottom of the stack. Examine the edges of an entire stack to gauge void frequency. Store vertical on long edge at least an inch off concrete. Cut with fine tooth panel blade to minimize face chipout.

Whatever you decide, build to the best of your ability and have fun.

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Posted by hon30critter on Tuesday, January 31, 2017 11:13 PM

To everyone who has responded, I just wanted to say 'thanks'. I'm getting some differing opinions but that is a good thing. There have been some good suggestions which I hadn't thought of so that in itself has made the thread worthwhile.

What I need to do now is sort out the pros and cons of plywood vs solid wood, and 'L' girder vs box style or maybe a mix of the two.

Please keep the suggestions coming.

Decisions, decisions....Confused

Regards,

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Tuesday, January 31, 2017 10:57 PM

trainnut1250
I used ¾ cabinet grade ply ripped into 1X3’s for parts of the bench work on my layout. Never again for me. The plywood boards were not as strong as dimensional lumber and there were voids that weakened the pieces (it was "cabinet grade").

Guy, you're scaring me!Smile, Wink & Grin

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by hon30critter on Tuesday, January 31, 2017 10:50 PM

j.c.:

j. c.
if the box store in your area will cut a sheet into 12" by 8'strips that would make easier for you to handle

There is an idea that is worth considering. Handling 12" wide pieces would be quite doable and they would be fairly easy to rip into narrower strips on my radial arm saw.

Thanks

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by j. c. on Tuesday, January 31, 2017 12:54 PM

well the lows here cut it for us but as i said it was cross cut not long way if they can cut it into 24" by 8' strips for you it would make it easer handling then just use a table saw or get the wood working shop at your club to 1 by 3 strips.

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

 

well local lows cut it into 4" strips 4' long , if the box store in your area will cut a sheet into 12" by 8'strips that would make easier for you to handle , then if you have access to a table saw recut the strips into 4" wide strips(will not be true 4"more like 3 and 15/16) if you don't have access then try to find someone to saw them.

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Posted by trainnut1250 on Tuesday, January 31, 2017 11:19 AM
Dave,
Another opinion for you.

I used ¾ cabinet grade ply ripped into 1X3’s for parts of the bench work on my layout. Never again for me. The plywood boards were not as strong as dimensional lumber and there were voids that weakened the pieces (it was "cabinet grade"). I found that the ply didn’t have the strength along its length and thus needed extra bracing.

 

I wouldn’t consider any using grades less than cabinet grade as they are potato chips (at least in the stores in my area).  For my dimensional lumber, I was able to carefully select nice 1X3 boards from the local box store for very little money that were much easier to use  (I go through the whole stack, opening bundles to find the best ones).

 

I use drywall screws and glue to assemble my L girder style bench work. Very quick, very strong. I pre-drilled when there was a danger of splitting the ends. I have used lots of plywood on the layout (all cabinet grade), mainly for roadbed and custom deck supports. I know that others have had good experiences with using plywood as dimensional lumber, it just didn’t work out for me.

 

As for bench work design, if you are going to have elevations, L girder is the way to go. Box style is good for relatively flat areas. I used both styles and other designs on my current layout.

 

Byron....So true.

 

My two cents,

 

Guy

see stuff at: the Willoughby Line Site

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