|Written by Bob and Pat Canfield for Family Garden Trains|
The B&P Garden Railroad (B&P) - Part 3 - Finishing Touches on an HDPE Roadbed
Note: This is a follow-up to Evolution of the B&P Garden Railroad Part 2. In addition, technical aspects of the following text will be best understood if you first read the Family Garden Trains Primer Articles regarding HDPE Flexible Roadbed by Paul Race, Bill Logan and Bob Zajicek.
Note for February, 2008: Since we posted this article, we've received inquiries about how, exactly, Bob fastened the roadbed to the vertical PVC stansions. The answer is at the end of this article.
If you'll recall, we decided in 2007 to build an Outside O Gauge railroad, using a raised roadbed made from HDPE planks that are split and reassembled into a ladder-like framework (see Paul and Bill's HDPE Roadbed article for an overview). By the end of Part 2, we had several sections of the roadbed installed but very little connected.
We were able to work on the B&P for approximately three weeks during November 2007. At this point the B&P infrastructure is held together with more than 2,000 stainless steel screws and Gorilla Glue. It is supported by 122 1.25" Schedule 40 PVC stanchions in concrete footings, 39 steel wall brackets, and one PVC trestle box structure. All HDPE roadbed and bridge construction as identified in our original RR-Track software plan has been installed.
The biggest challenges during this period of construction were the alignment of the North reversing loop, and the fabrication of a combination trestle/steel deck bridge across Lago Miele. We have affectionately named it Carmella’s Crossing, using Pat’s middle name.
Carmella’s Crossing, the combination trestle/steel deck bridge across Lago Miele was made to be removable, in case it becomes necessary for waterfall and lake maintenance. The center trestle section was made by modifying pre-made PVC Trestle Bents purchased from Split-Jaw Products. Using PVC strips, also purchased from Split-Jaw, we formed a trestle box structure that is secured to the lake’s drain cover with GE silicone. This PVC trestle structure, and two, 12" long one-inch aluminum “L” sections at each end, physically support an approximate 6' span of HDPE double mainline ladder structure.
To prevent sagging of the two approximate 30" spans of HDPE on either side of the center trestle structure, we used one-inch “L” sections of aluminum. Two approximate 24" long one-inch aluminum “L” sections were attached across the bottom of each 30" span. To simulate a steel deck bridge, 12" long, one-inch aluminum “L” sections were attached to each side of the HDPE double mainline ladder structure, three per side, a total of six on each 30" span (Photo 9).
We realize that the “scale” of the Split-Jaw PVC trestle timbers is more appropriate for G Gauge than O Gauge. Also, we know we’ve taken “liberties” when trying to replicate something resembling a steel deck bridge. However, it has never been our intent to build a scale, prototypical layout like many indoor O Gauge modelers do. Our intent is to have a fun place for our family and friends to enjoy outdoor time together.
We have successfully used Bondo Body Filler and Bondo Glazing and Spot Putty to repair and/or fill in HDPE gaps or mistakes. These Bondo products are designed for automotive body repair. Both the Body Filler and Glazing Putty adhere to almost any sanded surface, are water and oil proof, moldable, can be sanded and should be painted. (In his younger days, Bob used Bondo products many times for do-it-yourself auto repairs.)
The next three photos show three steps of Bondo Body Filler repair of an approximate 1/4" height variation (caused by a planning mistake) at the North threshold of Carmella’s Crossing.
In addition to using the Bondo products for fixing construction gaps, planing and router glitches, we used it to fill in every screw indentation directly facing our patio on all HDPE ladder roadbed. The lower left photo shows Bondo Body Filler being used to fill-in larger gaps where HDPE pieces have been joined, as well as Red Bondo Glazing Putty being used for smaller imperfections. The lower right photo shows the same section after it has been sanded and lightly painted.
As November drew to a close, the B&P received a complete coat of paint. To get into nooks and crannies that a brush and roller cannot, we used Krylon Red Oxide Primer spray paint as recommended by Bill Logan. We found Wal-Mart to have the best price on the Krylon paint. After the Krylon spray primer was applied, paint rollers and brushes were used to apply Rust-Oleum Red Oxide Primer, an oil-based paint with good UV properties. The following photo shows Pat on the North, and her brother-in-law, Karl in the foreground, painting the B&P.
Although the B&P had no track, our six-year-old Grandson, Joey, who lives nearby, conducted an inspection tour in late November. He immediately started to tell us which mainline he would run his train on, and exclaimed, Grandpa, “this is really Cool!”
An Unexpected Break In Action
Due to some unexpected, out-of-state business demands, we had to stop work on the railroad at the beginning of December. We hope to resume work on the B&P before early February 2008. At that time we will start installing wiring and track.
We hope our experience gives you some useful ideas and helps you plan your project more effectively. Please contact us through the Family Garden Trains Contact link if you have any questions. Just put the words "Questions for the Canfields" somewhere in your comments and Paul will forward them to us.
Bob & Patricia Canfield
Las Vegas, Nevada
Other O Gauge Outside Links
Update, February, 2008A reader asked how the horizontal HDPE roadbed was attached to the vertical PVC stanchions, since no screw holes showed. Bob sent this answer.
The HDPE Ladder Structure is attached to the PVC Stanchions with the same stainless steel screws we used to originally construct the ladder structure. This was done after initial roadbed alignment and levelling.
We followed a leveling process to achieve smother up and down grades, plus, to the extent possible, to ensure a level roadbed, using a small level across the ladder, parallel to the rail ties.
Our levelling was done using a laser level on a tripod. We initially established a "high-point" for the HDPE based on a height above ground necessary to clear the back of the waterfall. All other elevations were sighted as this height, minus, or plus "X" number of inches. Our elevations vary as much as eight inches. No grade is greater than two percent, most are about one percent. We probably set up the laser level more than a dozen times during HDPE installation, usually in the evening after sunset, when it was easier to sight on the white PVC stanchions. You may notice some black felt-tip writing on some of the photos of unpainted stanchions. These were elevation markings from the leveling process.
One reason the screw indentations may not show up very well is that, as we noted in one of the articles, we used Bondo products to fill in every screw indentation that directly faces our patio. This was done strictly as a cosmetic feature. I've attached a couple of photos of this process, prior to painting.
Stay Tuned! Bob's been taking care of real estate and other matters for a couple months, but he is under growing pressure from Grandson to get some track in place while the weather in Arizona is still tolerable. We'll keep you posted. :-)
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