Grade Crossing – III

Sanded
sanded_1200I used a 220 grit sanding pad to smooth everything out. I filled in some low areas with Patching Plaster. This appears to simply be pre-mixed plaster in a plastic tub .. handy. Some people may be upset by the variations in color .. (like my brother in law ..serious OCD) .. but that’s fine with me .. it tells us that the road has had a long, hard life.
Colored
colored_back_1200This was a process that ‘evolved’ as I went. I brushed AI wash across everything which left it blotchy. I then came back with a mix of Grimy Black, Grungy Gray and White weathering powders (Doc O’Brien’s) scrubbed into the surface. I came back with some MIG Brown Wash on the ties to highlight them.
colored_1200A closer look. I left (for now) the ‘stuff’ between the timbers lighter. It must be concrete. Don’t get hung up with whether it is concrete or asphalt. Asphalt .. also known as bitumen is a semi-solid form of petroleum. The primary use of asphalt/bitumen is in road construction, where it is used as the binder mixed with aggregate particles to create asphalt concrete. Concrete roads were often patched with asphalt concrete mixtures.
colored_CU_1200A closer look. I think the mix/contrasting colors/textures of Concrete, Asphalt Concrete etc. works. The slight tint to the timbers from the MIG Brown Wash I think works also.

The only thing left will be adding the ‘Dome Head Drive Spikes’ ..

Dome Head Drive Spike
DHDS_drawingThese Dome Head Drive Spikes – as their name implies are driven in with a sledge hammer. The thread forces the screw to turn as it drives in. A tool fits into the four notches so the thing can be removed (theoretically). A version without notches could also be used (notice it states this on the drawing).

In the diagram note that the head scales to 0.052 in. dia and the dome – such as it is .. sticks up 0.008 in. This says to me that a short piece of wire the right diameter could be inserted into a hole to look like one of these fasteners.

Wire for Screws
wire_1200I wandered around Lowes for a while trying to find something that would work to make the screws. The heads of these are 2-1/2 in. dia. This converts to 0.052 in. in O scale. In the Gardening Section of the store I found this wire with the Electric Fence supplies. It measures 0.048 in. dia .. which if you reverse would give you a 2.3 in. dia – close enough. Since they will be painted that even gives room for that.

A 3/16 in. dia drill is 0.0469 in. .. so that should work.

On an aside. Note that these Dome Head Drive Spikes that the slots in the head are optional. I actually think I could make these in O scale but that would require a Watchmaker’s Lathe and Dividing Plate .. which I don’t have .. so I will go with the option and create screws without the slots! (luckily .. I am not completey mad .. just close to it)

Finished
Finished_1_1200Like everything I do the term – “finished” is subject to change. The grade crossing isn’t intended to “jump out” .. it’s a grade crossing for gosh sakes. In fact .. what jumps out to me in this pic is that Mr McGregor needs some blacking on his shoes – and that I need to bring the trucks “up to snuff”.
Finished_2_1200The try at making – Dome Head Drive Spikes . worked pretty well. I used some ‘InstaBlak for Stainless Steel’ on the galvanized steel wire I used for the screws. I may go back with something abrasive and remove a bit of that on the spike heads that tires would be regularly hitting.

The biggest lesson learned from this is to put the spikes in the timbers prior to pouring the plaster. My spikes are placed at appropriate intervals in the timbers (either end center .. and another intermediate for the longer timbers) but without any relation to the ties underneath. My explanation is that they put extra ties under the rails/timbers since heavy truck loads would be running at right angles to the track. Sounds good I suppose – and might even make sense. Still .. even if that were true, putting the spikes in prior to pouring the plaster makes a lot of sense.

Finished_3_1200Couldn’t find anything abrasive that would rub off the top of a 0.052 in. dia spike head .. then thought to use a mechanical pencil lead to add graphite to the thing. Worked pretty well.


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