Any thoughts on wire & wire quality?

[chuck]

Gargraves (and Ross) outer rails are tin plated and solder very easy. The center (black) rail is another story. I wound up using a spade lug, silver grease and a small brass machine screw to mount the pig tail to the webbing under the tie level. I tried to solder to the black rail and it was not pleasant and it didn' work too well.

[ScaleCraft]

Gargraves (and Ross) outer rails are tin plated and solder very easy. The center (black) rail is another story. I wound up using a spade lug, silver grease and a small brass machine screw to mount the pig tail to the webbing under the tie level. I tried to solder to the black rail and it was not pleasant and it didn' work too well.

Not a real problem. Have to scrape the anodizing off, or, if you're setting track and don't have it affixed, mark the spot use a deburring tool to clean.
ACID core solder, to tin (and it works fine, 30+ years on both pikes, no rot of rail or wire), solder tinned wire (bent at 90) to the tinned spot with regular rosin core solder.
My buddy's railroad....huge...had one of those joints fail in 30 years, and one Tenshodo/Kemtron machine fail.

[G3750]

... consider using an electrically conductive grease on the inside to inhibit future oxidation. Silver stuff works great.

What is that? I am unfamiliar with it. Is this what you're talking about?

https://www.lowes.com/pd/gardner-bender ... v1EALw_wcB

George

[chuck]

That product is specific to Aluminum connections. Stuff we used was from an auto supply store, "battery terminal grease". No Ox Id is a more generic form used in a lot of electrical work. There are some that are based on silver powder that are meant for high current use and also support relatively high temp as well. Those are also quite expensive. The products are designed to keep moisture out, inhibit corrosion, and conduct electricity with minimal loss to resistance (not necessarily in that order)

[webenda]

There are some that are based on silver powder that are meant for high current use and also support relatively high temp as well. Those are also quite expensive. The products are designed to keep moisture out, inhibit corrosion, and conduct electricity with minimal loss to resistance (not necessarily in that order)

No grease is electrically conductive in the way I read your text Chuck. All grease is a dielectric, an insulator.

Use of grease on high current contactors is to 1) protect the contacts from air and moisture oxidation and 2) to prevent arcing as the contacts make and break, the grease being a better dielectric than air.

Thermal grease is used to partially do the same thing, protect the part and heat sink from oxidation and, in addition, to fill air voids, the grease being a better thermal conductor than air.

Adding silver dust to thermal compounds increases thermal conductivity but does not make them electrically conductive. Used in switches, the switch contacts push the grease out of the way as they make contact. The silver dust is carried by the grease, out of the way.

Silver dust makes the grease capacitive. Each silver particle is suspended in a dielectric and the combination can store an electrical charge. If some silver grease flows onto circuits, it can lead to malfunction.

MG Chemicals Silver Conductive Grease has, in addition to silver dust, graphite dust. This grease will dissipate static charge but is hardly a good conductor. MG does not give any electrical conductivity values for silver conductive grease but they do for graphite/carbon conductive grease, 160 ohms-cm. 160 ohms-cm is equivalent to 1,563,979,283 ohms/foot in a 20 AWG wire.

References: https://www.translatorscafe.com/unit-co ... hm%2Ffoot/
https://www.mgchemicals.com/products/gr ... rease-8463
https://en.wikipedia.org/wiki/Thermal_grease
http://four-point-probes.com/understand ... surements/
https://www.w8ji.com/dielectric_grease_ ... grease.htm
https://youtu.be/q_xtms0yd6E

[chuck]

Take it up with their copywriters. They are the ones describing the martial as "grease".

Some of the products explicitly state the material is to be used where parts are moving and some offer variants that are meant to be used in static applications.

[Roy]

George, electrically, there's no substitute for a properly soldered connection. In your situation, with the large model railroad you're building, I'd say stop whatever track laying you're doing, and learn to solder. Let it take a week, a month, or whatever. You're what, 50, 100, 3000 years old? Just take the time. Get a sufficiently powerful iron, to do the job. Basically, for soldering, you need an immaculately clean metal surface, and sufficient heat. You'll need to use flux, to keep the surface clean while you heat and solder it. You need to solder all rail joints, plus the wires connecting to the rails. Forget about relying on rail connectors, or anything else, to assure proper current conduction.

Also, if you're doing three rail O, don't **** around with your locomotive operation. Connect both running rails together electrically with low-resistance soldered connections, in many places. For your signals, you can use electric eyes, or even those silly Marx copper rail overlays. There are plenty of options, for triggering signals and accessories. It's flat stupid, to not have the very best conduction path to your trains.

Since there's only the one center rail, you have to be twice as vigilant, to assure proper conduction to your train. Do as Dave says, and solder your blackened center rail segments together, just like the running rails. In addition to a deburring tool, you can also use sandpaper, emery cloth, a file, or a Dremel tool, to remove the black oxide layer. Once the connection is soldered and the flux removed, you can re-blacken the rail with gun bluing, or black paint.

I don't understand using stranded wire, for a bus. It doesn't need to move. To carry the same current as a solid wire, you need heavier stranded wire.

Also, it is possible to solder stainless steel. You do have to use the correct type of solder, and flux.

[chuck]

Soldering is a skill worth learning and it shouldn't take that long to master the techniques you will need for three rail train operation. You will need a heat source in the 100 watt range to solder the track and as noted in several previous posts you need to make sure everything is clean. You also want to make sure the joint is physically stable when you solder. Solder is eutectic. The transition from liquid to solid is almost instantaneous. There is nothing more frustrating than winding up with a cold solder joint because the work shifted just as it cooled.

A good choice for the iron/heat source is one of the Weller guns. These use induction heating and reach operating temperature in a few seconds and cool down considerably faster than a traditional iron. They are also easier to handle/maneuver and some have led spot lights to illuminate the work area.

Try to do as much work above the table, i.e. the track feeds. Working with mean old Mr. Gravity is much easier and safer. Flip track on its back and attach feeds. You can make leads long enough to run under the roadbed to holes you drilled in the table or drill those holes as you go along installing the track. You can get liquid electrical tape to insulate the three way joints where the feeds attach to the bus. It comes in black, red, and white. When working under the table NEVER put yourself in a position where molten solder can drip down on you. When soldering stranded wire to stranded wire the stuff will wick into the joint. Soldering from the side is easier/safer.

[Roy]

You can get liquid electrical tape to insulate the three way joints where the feeds attach to the bus. It comes in black, red, and white.

Good to hear of this. I wonder if it was developed from tool handle dip?

[chuck]

Not sure which came first. Started seeing them around the same time. I like not having to leave joints that are hard or impossible to heat shrink or resort to trying to wind a complex "bandage" of sticky tape in cramped spaces.

[v8vega]

On the 3 way where the drop down from the track to the buss, if there is nothing for it to short to, I just leave it bare. If you tape it I find the tape tends to come undone so I uas rubber glue or some kind on the end. Clean excess flux off the track solder joint with alcohol which I have heard you can't get anymore.

[Rufus T. Firefly]

When working under the table NEVER put yourself in a position where molten solder can drip down on you.

While well noted, it seems a oft time ignored condition.

That one switch machine that you cannot reach otherwise to replace will be in just such a location.

[chuck]

I use this stuff to clean up the ruby red flux I use on stained glass which is pretty thick and sticky.

https://www.spraywayretail.com/product/ ... x4QAvD_BwE

You can spray into a rag/microfiber cloth if you don't want to flood the area. This is a really great foaming GP cleaner. We used on carpet spills. Foam lifts stuff. This and a dry lock baby diaper were pretty much the go to carpet cleaning tools. Keep a can in trunk for window/auto upholstery cleaning.

It's pretty good at knocking down flying insects at close range. The foam fog usually nips the insect and once it's down a quick burst floods them. If they manage to skulk away before you can finish them off with a Kleenex or paper towel they are drowning in the alcohol and will expire shortly.

Even though you are not moving the wires around I have found it safer to insulate these connections. Too many times you get under the table with a screwdriver or wrench and accidentally make contact with something you did not intend to. This is a CC layout with multiple PH 180's running at full or near full voltage.

[G3750]

First of all, I want you ALL to understand that I appreciate the feedback - good and bad. Your helpful intentions are unmistakable and I am grateful.

I have given this much thought and this is what has emerged:

• I am not comfortable with soldering. I don't do it well enough to have confidence in an overall, consistent result.
• In particular, I am uncomfortable with soldering under the layout.
• Time is not on my side, so I am going with the familiar.
• I will have to exercise caution and diligence in making crimps - this has been a problem with me in the past. And I have addressed it with an improvement in tools and technique.
• I will not be tying the 2 outside rails together. I don't think much of pressure-style rail contact actuators. And IR sensors for block occupancy would require a shorter train to stop precisely in front of the censor.

Thank you again for weighing in on this. I will let you know if I change my mind or my direction proves false.

George

[chuck]

I respect your concerns re soldering. The blackened center rail is a pita to solder.

If you had minimum issues with connectivity on the old layout using the techniques you outlined, stick with them. Go with what works for you AND you are comfortable doing.

I only have one question re isolating the one outer rail for signalling. I am assuming you don't have any explicit reversing loops? I.e. where track loops back on itself?