The LK&O Railroad

[LKOrailroad]

Decided on bracket style for benchwork mounting to the walls. Thought I would have to wait until after Christmas present bills are paid in January but wife surprised me and said go ahead and order them now. Cool! A big box of them are on their way.

http://www.lkorailroad.com/benchwork-brackets/

[LKOrailroad]

Benchwork has begun! Built the first of many sections today. On vacation over the holidays so should be able to make great progress. Using framing angles for attachment instead of the usual end grain screw or pocket screws. This will allow me to reposition cross members from below if changes are needed later on due to track change, the need to locate an actuator, etc. I am positioning the cross members so they don't interfere with switch machines and linkages hence the track plan on the floor. The doubled up cross members are where the wall brackets attach. This particular section is the west end yard throat of Brittain.

[GaryHinshaw]

Sky blue walls, full-scale track printouts from XTrakCAD, box benchwork construction -- looks familiar!  That's the point I was at almost exactly a year ago (except you don't have the mess I did...).  Looks great!

[C855B]

... Using framing angles for attachment instead of the usual ... pocket screws. This will allow me to reposition cross members from below...

OK... now I'm puzzled.    How do pocket screws defeat relocating from below? I was planning on pocket screws - in fact, just yesterday I made sure I knew where my jig was. Anyway, 4 screws per brace vs. 16 for the framing angles seems faster and easier. What part of the process am I missing here?

[Philip H]

I've found pocket screws in plywood are tough to use, in that tightening them down of ten pushes the plus apart causing the joint to fail. They're a great invention for a lot of permanent applications, but this may not be one if them.

[LKOrailroad]

I've found pocket screws in plywood are tough to use, in that tightening them down of ten pushes the plus apart causing the joint to fail. They're a great invention for a lot of permanent applications, but this may not be one if them.

Philip is spot on. I tried pocket screws on a test piece. They tend to push apart the plies resulting in a weak joint. Pocket screws were my original first choice but switched to the framing angles after testing the pocket screws in the actual plywood I am using.

The framing angles certainly are not the fastest assembly method. A lot of clamping, marking, pilot drilling, and screw turning going on. But it is not like I am running a production factory!

[C855B]

Ah. Pocket screws in plywood. Check. I'm still having the plywood vs. 1-by discussion with myself.

[LKOrailroad]

Easy decision - plywood. Pain to rip the sheets but once done it is marvelous to work with. No warp, twist, or bow. Every piece exactly the same width.

[central.vermont]

Yes plywood is the best choice. It's cheaper then clear pine by the foot. And like LKO said it is a very stable product to work with. I must say that I did not have any splitting problems with it as long as you pre-drill all your holes. One thing I did was to make sure that where ever there was going to be a switch I did not have any cross members placed in the way. I also drew up my layout in Xtrak cad and printed it out full scale just fro the reason to keep cross members clear. I also glued all of my joints with Tight Bond yellow glue.
One other thing about the plywood is to make sure you get the marine grade, this will give you maximum ply's to help eliminate splitting.
I also painted all of my bench work with a cheap flat white paint as well as the plywood decking on top. This helps to make it brighter under the layout when you are in there doing wiring. It also helps to reflect the light down on a multilevel layout such as mine.

Keep up the good work!!!

Jon

[C855B]

Yes, I grok the dimensional stability advantages of plywood. You mention ripping down the sheets - I'm looking at a lot of saw time for this. My experience adds issues with additional milling - dadoes and rabbets for joinery, for instance. On my most recent project I lost track of how many nearly-finished pieces went into the scraps barrel because of tear-out on the last rabbet. (Lesson there, finally, was not to use the dado setup for rabbets on ply. Duh.)

At the moment - subject to change at any time, and YMMV - I'm thinking a hybrid approach. Plywood for the basic boxes and "finish quality" dimensional for the cross-members. Less saw time and the flexibility to use pocket screws on the braces. Also, using the less-stable wood for the short pieces minimizes the effects of any warping and dimensional changes with humidity.

[LKOrailroad]

I put up a blog post that explains my method and rationale. http://www.lkorailroad.com/benchwork-construction-methodology/

[Dave Schneider]

Looks great. I have been using a biscuit joiner to make my butt joints between the side rail and the cross members. I am using 3/4 inch plywood and it produces a very strong glued joint.  You might want to consider drilling some holes for the wiring bus in the cross members prior to assembling the frame.

Best wishes, Dave

[LKOrailroad]

You might want to consider drilling some holes for the wiring bus in the cross members prior to assembling the frame.

Gave thought to that. Decided to bore holes after risers and switch machine locations have been identified. I have a right angle drill so no biggie to get access.

[Bendtracker1]

One other thing about the plywood is to make sure you get the marine grade, this will give you maximum ply's to help eliminate splitting.

Jon, one note about your Marine Grade Ply;  Marine grade ply does not always ensure the maximum amount of ply's.  If your looking for the maximum amount, then look at Baltic Birch plywood.  1/2" BB will have 11-13 plys, 3/4" will 15-17 plys depending on the mill.

Marine plywood is manufactured from durable face and core veneers, with few to no defects so it performs longer in humid and wet conditions and resists delaminating and fungal attack. Its construction is such that it can be used in environments where it is exposed to moisture for long periods. Each wood veneer will be from durable tropical hardwoods, have negligible core gap, limiting the chance of trapping water in the plywood and hence providing a solid and stable glue bond. It uses an exterior Water and Boil Proof (WBP) glue similar to most exterior plywoods.

On my most recent project I lost track of how many nearly-finished pieces went into the scraps barrel because of tear-out on the last rabbet. (Lesson there, finally, was not to use the dado setup for rabbets on ply. Duh.)

Mike,
I use dados and rabbets in plywood everyday in my cabinet shop.  The trick here is to use a quality grade of plywood and to always  keep your tools sharp!  You still get some blowout, but it's kept to a minimum.

[LKOrailroad]

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