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The next step is the process of fastening down the door slabs. Up to this point they have been just sitting on the shelf brackets so we can easily move them around or get them completely out of the way if we need access to something.
We want to get the upper facia and lighting installed. For this, one of the critical measurements where we want to be sure we have consistency, is the distance between the facias. For access to the upper deck, we plan on a 12” gap between the upper and the middle facia. This means that the height of the upper facia needs to be measured from the surface of the upper deck to ensure they are always parallel. For this to happen, we need the upper deck in place and fastened down, so we know its exact permanent location.
Also, now that we have all the skyboard backing in place, we are pretty sure it is safe to go ahead and fasten down the upper deck. We are going to hold off on the lower deck for now so we can easily get at the underside of the upper deck while finishing up lighting.
Given that the doors are hollow, you must have a plan for everything that you want to attach to them and for how you will attach the doors to anything else. The only place a hollow core door has any framework that will hold a screw is within a 1” margin around the outside edge. Even that you cannot count on. I discovered that on the door slabs I am using, the bottom frame member is about 1” thick, the sides are about ¾” and the top is about ¼” thick – not a lot of room to work or hold any screws. Additionally, the frame members in the doors are made of what I would describe as particle board made from compressed cardboard (not even solid wood). While incredibly easy to cut, when it comes to screws they are quite soft. You want to make every effort to make sure that all screws are driven in the frame's center of mass - too near the edge and the material flakes apart.
Being aware of this, the plan is to glue the door slabs down on wooden “shoes” that are attached to the shelf brackets. I discussed this earlier in the one of the first posts The Mud Bay & Western #3 - Roughing in the Benchwork.
The idea being that the wood shoe would provide more surface area for mounting. This would distribute the weight better on the thin door skin and provide a larger glue surface for a stronger bond. Here’s the first door in place:
If you look closely you can see the bead of glue run along the shoe on the next shelf bracket as we prep for mounting the next slab. By the way, we use TightBond 2 as our glue of choice. It is easy to work with and bonds wood surfaces well. Here’s a closer shot:
Making sure that all the mounting points were even (height-wise) and level ahead of time, as well as the uniformity of the door slabs made this process pretty easy and it went fast. The glue joints provide a good strong mounting point. After placing each slab, I inspected the underside to make sure it was well seated and there were no gaps. Also wanted to make sure to wipe off any excess glue before it squeezed out and dripped on the layer below. I was a little generous with the glue applied to the shoes to ensure a good bond.
Even though the doors are pretty uniform and straight and we had made sure all the mounting points were even, we put weight on them after mounting each slab to ensure there were no gaps while the glue dried. In this case I used paperweights - raided my magazine rack and used my collection of Narrow Gauge Gazettes and Finescale Modelers…
A box placed over each bracket did the job. I left them there over night while the glue set.
Joints Between Door Slabs
Even though the doors are uniform, I wanted to make sure that the joints between the doors were perfectly even. We have mounting brackets every 32”. This provides 2-3 brackets to support each slab. With the exception of one location. The joints between all the slabs occurred between two brackets. This meant those joints were floating in space.
To ensure the joints were stable and that the door surfaces would remain precisely even with one another over time, I decided to attach a joining plate to the underside of the slabs to bridge each joint. This may seem like overkill but a small difference can cause a problem if it happens to be at exactly the wrong place. Also, given that I am working in N scale, even a 1/16” error can be a real headache for smooth track. The joining plate would help ensure that the top surfaces of the slabs are perfectly aligned – something we will appreciate when we are laying track later on.
The joining plates are simply a 2” wide strip of ¼” cabinet grade plywood (cabinet grade has more layers, tends to be stronger and more stable than generic plywood). Given that I don’t have more than a one inch margin for screws in the door frames, I didn’t see the need for the joint plates to be wider than 2” ( 1” for each side of the joint).
One of the design goals of this project is to make it possible to remove the layout when I am gone, or we decide to sell the house. I realize that 95% of the time a layout doesn’t survive the process, but it crosses my mind to wonder if that is because they were not designed with removal in mind. Most folks are focused on strong and stable rather than portable.
I have seen attempts to remove a couple layouts and it can be painful to watch. With that in mind, our design leverages the natural “modular” nature of the doors and as I install everything, I keep removal in mind. In this case, I am treating each door slab as a potential module that could be removed with minimal damage if necessary.
This means that the joint plates get permanently mounted to one side of the joint (glued and screwed) and then only temporarily mounted (screws only) to the other side of the joint. I marked the “glued” side of each plate for later reference. Prior to mounting the slab on the shelf brackets I glued/screwed each joint plate to the end of its door slab and predrilled the “screw only” holes in the slab next to it. This was MUCH easier done while the doors could be turned upside down rather than crawling around under the doors after they were mounted to the wall.
After the slabs were mounted to the brackets, we followed up with driving the screws into the pre-drilled holes on the “screw only” side of the joint plates. This process wasn’t too bad either because the holes were all pre-drilled and we could remove the lower level doors to make room for the drill while driving the screws.
Given the soft nature of the door slab frames, we pre-drilled all holes. We found that the cardboard/particle board material used to make the frames tended to break apart and flakes of material pulled away if we tried to self-tap screws without pilot holes. We found that a small diameter pilot hole (we kept it as minimal as possible to leave as much material for gripping the screws as possible) allowed screws to drive without any flaking off of material.
Fastening Down the Peninsula Door Slabs
While we used wood shoes bolted to the shelf brackets and glued the slabs to them around the walls, with the aluminum framing on the peninsula, the rules change completely.
In an earlier post: The Mud Bay & Western #3 - Roughing in the Benchwork I discussed the aluminum framing we used for the center peninsula.
The square tubing we use for the support arms is nice and flat. It is also plenty wide to easily drive screws through. I will admit to a personal bias here: I am not a fan of gluing stuff to metal. In my book, if metal is involved I will always lean towards nuts and bolts or screws as my fasteners of choice. In this case, given the flat, smooth, and square door slabs, and the flat, square, and smooth tubes, it is a simple matter of lining everything up and driving the screws.
The key here is “aligning”. There isn’t a lot of room for error on the peninsula. While that would seem to go without saying, there are two considerations in play here:
First, the peninsula is framed in aluminum. I like working with this material. It’s strong, light, and very easy to work with. It drills as easily as wood and I have a carbide blade in my chop saw so I can cut it as easily as wood too. The thing to keep I mind though is that metal is unforgiving. What I mean by that is that with wood, if you end up drilling a hole 1/16” inch off or you have two pieces a little out of whack, you can make small adjustments on the fly without too much trouble. Just tighten something a little more in one place, maybe loosen something a little in another. The wood flexes easily along the way and the tiny mistakes are not an issue.
Metal is not like that. If your holes are off, even a little bit, you probably won’t be able to get the bolt through or, once it is all assembled, things will be really out of square. With metal, you need to up your game a bit on accuracy.
Second, using screws to fasten the door slabs means that the target area for all screws is the interior frame of the door which is within a 1” margin around the outside edge of the slab.
The design of the peninsula frame is such that there are support arms that line up with each end of each door slab with an additional arm supporting the middle of the longer slabs. The lengths all align exactly with the outer edges of the doors. We had to be careful here because if the arms stuck out at all (even 1/16”) it would interfere with the facia mounting. Yet if an arm was even a 1/2" short it would mean we would miss the door frame when trying to drive a screw.
This photo gives a good view of the arms and shows us placing some slabs to test fi. Note some of the pre-drilled holes in the aluminum arms:
We pre-drilled all the holes. Their positions needed to be perfect and I had no desire to be crawling around underneath everything trying to drill all these holes after the frame was assembled. Given the uniform nature of the door slabs we knew ahead of time where every screw would go so all holes in the aluminum were drilled before the peninsula frame was assembled.
In the photo you can see some large holes in the square tubes. If you look closely near the post you can also see some smaller holes. The the larger are access holes that allow us to get a wrench or screwdriver on the fastener being used in locations where the bolt/screw had to be countersunk so the heads would not interfere with a door's location on the arm. The smaller holes were for the screws that attached the doors to the arms. The peninsula frame itself is assembled using 1/4-20 nut/bolt/washers. The doors were fastened down with 1” sheet metal screws.
Given the soft nature of the material used inside the frames of the door, in addition to using pilot holes, I dipped each sheet metal screw in Tightbond II wood glue before driving it into the door. This was to lend some stability to the hole in the door frame after the screw was driven.
We cut the door slabs to fit the end of the peninsula and wrap around the last support post.
Once everything on the peninsula was firmly butted up to the section that was already attached to the wall, properly aligned with all the arms and each other, we began driving screws. We started at the end nearest the wall and worked our way around to ensure that each slab properly aligned to the previous one. For the most part that went as expected. The screws along the back edge of the door slabs proved to be a bit of a challenge simply because clearances were so tight to get the drill in position. One thing that made it vastly easier was the fact that we had not fastened down the lower level doors yet so we could remove them while installing the upper level.
A small aside here about a tool that also made this easier. While we predrilled all the aluminum, I waited until we were mounting the doors to drill the pilot holes in the door frames. I wanted to do this while they were in place so the pilots would positioned as perfectly as possible (once again insert caution here about small margin of error and soft door frame material). A tool that made this much easier was a flex shaft attachment for my drill:
I have used one of these for years. It was a cheap, generic attachment but came in handy. The one problem was that it was pretty light. Recently I found this heavier DeWalt Flex Shaft from Aamazon. It is considerably heftier. While I don’t recommend trying to drive screws with these (possible if the screws are not too big and you are using soft wood) , it comes in handy when you need to drill holes in tight spaces.
Anyway, back to the layout. After mounting the first slab we got the hang of it and it only took about a half hour to get the rest of the upper deck doors screwed down. Overall we are happy with the installation. It is very clean and rock solid.
After finishing up attaching the slabs for the upper deck, we spent a day in the shop sawing wood. I have all the parts cut to start working on the upper facia and lighting valance and I have the large light panels cut for the upper lighting. My Amazon box arrived with the lights I need for those panels so the next steps are going to be the upper lighting valance and begin installing light panels.
That will most likely be the next post. See you then.
This article first appeared on model-railroad-hobbyist.com
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