Re: Resistance Leak from Fast Track turnouts

Richard Sutcliffe
 

Guys

A very,very high resistant short circuit.
Not enough current flow to trip any circuit protection, but enough current to heat the circuit over time and cause damage.

I have had leakage through a grain of ballast from the bottom foil to the top foil of a PC tie. Over time (several years on a club layout) the small amount of heat destroyed the resin until the foils touched. Then it took a while to find the now significant short that was tripping the circuit protection. The area became apparent when a heavy loco was in the same place when the “short” occurred.

Another one was a Walthers passenger truck with one wheelset across the gaps at the end of a reversing block. In a much shorter time than above, the wheel softened enough to move on the axle causing a derailment. But did not trip the auto reverser.

Both cases there was a very high resistance short, just a tiny leak of current.
I’m sure many can relate to the term resistance leak.

I avoid the use of double sided PC ties, to the extent I heat & peal the the one foil off the tie before building the turnout. I usually do the pealing before cutting the ties to length.

On Feb 8, 2020, at 9:43 AM, Gary Chudzinski <chudgr@...> wrote:

Like Brian, I have never heard the term, resistance leak.  I can't even imagine what it means!  I have built many Fast Track turnouts in over ten years and the only thing I can think that it relates to is high resistance between track and Circuit Breaker tie due to corrosion.  Corrosion that may have built up over time because an acid Flux was used and not properly cleaned, rather than a resin core solder, or a liquid resin with the solder.  In the early years, a Flux was recommended by Fast Track for a stronger bond, but reading the instructions for this application was a must! After completing the turnout, it was necessary to thoroughly wire brush the joints to remove the bulk of the Flux residue, than wash with soapy water to remove any remaining residue.  In so doing, I have never had any problem with corrosion.  However, in more recent years, Fast Track recommends using the Resin Core solder they sell.  Refer to their website.  Look under Tools and Supplies, and read the Description under both Flux and Resin Core Solder.  Corrosion is not a problem with their resin core.  

Gary Chudzinski


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