Materials, Tools, and Techniques for Outdoor Track

Questions and Ideas to track building, how are you doing it? need help? new features? share your ideas.
Ned
Posts: 368
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Materials, Tools, and Techniques for Outdoor Track

Post by Ned »

I have been experimenting with materials, tools, and techniques for building a road course permanently located on the ground outside in Sedona, Arizona, USA. Normal low temperature is 15° F and normal high temp is 100° F for a typical year. We get less than 18" of rain a year and about 2" of snow. The sun is extremely intense in June. The latitude is 35 degrees north. Much of the circuit will be a compact representation of a portion of AZ highway 89A between Sedona and Flagstaff, known locally as the switchbacks. When complete the circuit will be about 130 ft long with a 3 ft change in elevation.

Over a period of 5 months I have tried at least 10 different combinations of materials, tools, & techniques. I have decided that any material made of wood fiber, such as MDF, will not work outside on the ground because it expands, contracts, wraps, and twists too much with changes in humidity, or exposure to rain, even with 3 coats of paint on the top, bottom, and all the edges.

I have found that 1" thick Owens Corning FOAMULAR extruded polystyrene pink insulation board works best as the baseboard for my track which is made in sections and attached directly to the ground after excavation and grading. This material which comes in 4' x 8' sheets is not affected by moisture but an 8' piece painted medium/dark gray will expand about .25" when ambient conditions change from 65 F in the shade in the morning to 100 F in the direct sun at noon in mid June on a clear day in Sedona. I estimate that the track surface reaches about 150 F when exposed to direct sunlight at noon in June. The vast majority of the expansion is caused by the intense radiation. It would expand less if the surface were painted white.

This insulation board is not resistant to UV radiation nor is it resistant to solvents such as paint thinner, acetone, mineral spirits, xylene, etc. It must be painted with water based coatings to protect it from UV. Adhesives with strong solvents must be used very sparingly and very carefully. Compared to 3/8" thick MDF, this 1" thick insulation board is much lighter in weight, and much easier to cut, drill, sand, and bend. However it is not strong or tough.

Following are the steps I take in making a section of track which is usually 12" to 16" wide and 4' to 8' long:
1) Glue 2-3 smaller pieces of board together, if needed. Sand track surface at joints if needed due to variations in thickness of board.
2) With foam roller, apply 1 coat of white elastomeric roof coating to top surface and any edge that will be exposed to direct sunlight.
3) With a fine black felt tip pen, precisely indicate where the piano/music wire is to be embedded in the surface. A flexible lexan strip available from oldslotracer.com works well for drawing complex curves.
4) With .060" x 1.25" brads (nails) attach a straight edge or flexible lexan strip as needed to serve as a guide for cutting a groove in the board. These nails can be pressed into the board without any tools.
5) With a .035" diameter router bit in a Dremel tool with a router attachment, cut a slot about .038" deep.
6) With the aid of a wallpaper seam roller press 36" long pieces of .032" diameter straight music wire into the slot and cut to length as needed. (I use .032" x 36" music wire because it works very well and it is cheap and readily available from ACE Hardware.) Leave about a .060" gap between the ends of 36" long pieces of wire to allow for expansion, if track will be exposed to very intense sunlight. Leave shorter gaps between shorter pieces. Avoid gaps in tight curves by using a single piece of wire. Do not include a gap close to a lane change.
7) Remove the wire from the slot. Run a tiny bead of glue in the slot and then replace the wire using the roller to press it down flush with the track surface. Wipe off any excess adhesive. Do NOT use PVA glue, also known as wood glue, carpenter's glue, and white glue because it is acidic and will cause the wire to rust if the track gets wet. The adhesive you use is extremely important, if the track will get wet. The proper adhesive/sealer will prevent the wire from rusting. (Beware, many adhesives are acidic.) Do not count on 2-3 coats of water based paint to protect the wire from rusting. I know from experience. I had to throw out about 30' of track.
8) After the glue has cured, using a small artist's paint brush, apply a coat of elastomeric roof coating over the wire and immediately scrape off the excess with a straight wide blade putty knife. This helps to hide the wire and hold it in the slot.
9) Patch nail holes and any dents in the board. When dry apply 2 more coats of elastomeric roof coating to the entire top surface of the board.
10) Now color the entire surface with water based exterior flat house paints and decorate as you wish.

With all of the roof coating and paint on the track surface, it is quite tough and easy to clean. I glue sections of track together using 8"-12" wide pieces of insulation board placed under the seam/joint. Then I seal those joints with caulking compound or elastomeric roof coating and paint. Many types of adhesives will work for connecting sections together. I also glue cleats of scrap insulation board approximately every 24" under the track to prevent the track from sagging.

I would appreciate any ideas for building an outdoor track or improving on what I am doing.
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Joel, LeNoir
Posts: 107
Joined: Fri 21. Dec 2012 21:47
Location: Washougal, WA.

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Joel, LeNoir »

Sounds great. Can't wait to see it. Have you played with a low grade stainless steel wire? Has magnetic properties but doesn't rust.

My outdoorish track will be embedded in the floor of a completely covered porch in a very wooded area.

Looking forward to seeing your progress.
WesR
Posts: 371
Joined: Fri 21. Dec 2012 17:37

Re: Materials, Tools, and Techniques for Outdoor Track

Post by WesR »

All very interesting Ned. Looking forward to seeing some pics.
Nor Cal Mike
Posts: 183
Joined: Fri 21. Dec 2012 22:22

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Nor Cal Mike »

Ned, Are you doing Black Oak Canyon? That is a very beautiful place. Are you going to landscape the track? As to rust, other than longevity for the wire, would rust matter? The stainless Joel suggested would cure that. you would have to experiment with various sizes to try to find the same magnetic traction standard sized wire.

I have thought quite a bit about outdoor tracks too. I was thinking about bondo ( automotive body repair filler) over fiberglass as a surface. I was thinking of the 1/8" fiberglass sheets that can be purchased at building supply stores. It is used in public restrooms a lot. I used it as the finish surface on a tear drop camping trailer that I built 10 years ago and it is still going strong. It has a bumpy face surface but the back side is flat. I put it on my trailer face side down. You could glue the wire to that and then fill the roadway up to wire height with Bondo. If it is painted, it will last a long time especially if it is stationary.

We use the pink foam for scenery on the model train layout that a train club which I am a member. We find that the cheap Liquid Nails brand adhesive works well with it.

I look forward to seeing your progress Ned.
Ned
Posts: 368
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Ned »

Joel, thanks for the idea concerning wire. Does anyone know where I might buy low grade stainless steel piano/music wire, ideally in 36" lengths? Is it called "low grade" or is there some nomenclature I need to know to order the right wire?

Mike, I'm modeling Oak Creek Canyon which is probably what you're thinking of. Yes it's very a beautiful place. I will be landscaping it with a combination of real and model dirt, rock, plants, trees, shrubs, grasses, cacti, etc. I'm installing an irrigation system now to supplement the little rain we get. Will be installing some real plants during the next week.
As to rust, it quickly affects the longevity of the track by causing the wire to rise up out of the groove in the baseboard material and become loose. The rust seems to increase the diameter of the wire. Thanks for the idea concerning fiberglass and Bondo. I've never worked with Bondo. What is the consistency? Does it spread like plaster? Can it be sanded? What about expansion and contraction? Is it at all flexible? I'm using some of the pink foam board for terrain modeling also. Thanks for the tip on Liquid Nails.

About 1/2 of my track is complete. I installed a shortcut to make a loop for racing now. Couldn't wait until all of it, about 135 feet, is done. Will see how this 1/2 weathers during the next few months before resuming construction of the remainder. May start experimenting with stainless wire and Bondo. I'll be posting some pictures in the near future.

Thanks for all of your feedback.
Nor Cal Mike
Posts: 183
Joined: Fri 21. Dec 2012 22:22

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Nor Cal Mike »

Ah, Oak Creek Canyon. I've been through here a couple of times but it has been at least 35 years since my last visit. I recall in less than an hour you descend from alpine woods to red rock desert country.

As to bondo, It is designed for body work on cars. That requires some flexibility and also must stand up to changing temperature and moisture. It holds paint well. It does spread like butter but once set it is fairly hard to work short of a rough file and or power sander. Gross shaping should be done at the stage where it is just starting to get hard using a course body file.

I cant't tell you where to find the stainless wire but I think in your climate the hard steel of piano wire may be sufficient. You may have to go over the wire once in a while with a sanding block to remove any rust on the surface. My G scale model train club does that regularly on the brass rails in our outdoor section of tracks to maintain conductivity. Freeze might be an issure regardless of wire chosen. Whichever type wire that you you use will inevitably get moisture between it and whatever filler that you use. Frozen water expands which might cause issues.
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Joel, LeNoir
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Joined: Fri 21. Dec 2012 21:47
Location: Washougal, WA.

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Joel, LeNoir »

Hello. did a little research and it looks like magnetic stainless steel does exist. The 400 series, which contains steel and chromium, but without the presence of nickel, does in fact exhibit magnetic qualities. Any stainless steel that contains nickel will not be magnetic.

Another option would be a galvanized steel wire. This would have a rust inhibitor....

Both of these would be available in a wire spool.

Would really like to see what you have done thus far.
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Lasp
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Joined: Wed 16. Jan 2013 16:35
Location: Helsingborg, Sweden

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Lasp »

Woov Where is the pictures? And corning the moving of different material. Keep the wire in shorter parts, If you get 1 mm in gap in the WireWay the car dosnt matter ower that!

But it will be a good experience to see all this.
Good luck from Lasp
Ned
Posts: 368
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Ned »

Sorry for the delay in posting pictures. Mine were all too large for the forum. Still learning how to post image files over 256KB. I hope this works.

As I indicated earlier I am making a model of a 2 lane country road in northern Arizona. About ½ of my road course will be a representation of a short very windy portion of highway 89A through Oak Creek Canyon north of Sedona, AZ. The model is permanently located outside on the north side of my house on a gentle hill behind a retaining wall.

I used Google Earth to help make the drawing for laying out the foundation of the road course. See the photo below. After experimenting with a roundabout in the southeast corner I abandoned the idea. I also shortened the pit lane and eliminated any curves going from the southwest corner to the southeast corner. Because it was taking so long to build the circuit and because of the uncertainty concerning whether or not the track would survive the weather here, I installed a one lane shortcut by a hairpin turn on the eastern side to complete a loop. These modifications are not shown on the drawing.

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Here are a couple of photos of the foundation under construction.

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If these photos appear as I expect, I'll be posting more in the near future.
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Lasp
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Joined: Wed 16. Jan 2013 16:35
Location: Helsingborg, Sweden

Re: Materials, Tools, and Techniques for Outdoor Track

Post by Lasp »

This is a Greath Idea, and a Greath job!
There is many task too to Solveig, but I guess it vill bee.
Good work!
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