Conductive Epoxy Instead of Soldering to Rails

How easy does it set, do you have to secure it someway till it cures?

Are there any specifics involved, brand name, conductivity, usage parameters?

I tried some years ago. Was not impressed. Might be OK for milliamp currents but i would not use it to try and run trains. 

Are you saying electronics made in Europe have be epoxied together rather than soldered? Hard to believe you can epoxy a computer chip to a board.

Pete

I think you're going to find out that "conductive" epoxy won't carry near the current required.  In addition, it's WAY more expensive than solder!  Lead solder is outlawed in the EU, but not lead-free solder, don't throw out the baby with the bathwater.

Conductive Epoxy Can Replace Solder

However, some of the attributes don't seem all that desirable, at least to me.  Are you willing to make a joint and wait 24 hours?  How about dragging out the heat gun and heating it for about an hour?

In high-flexibility applications where stress cracking is a problem, such as in chip-on-flex or flex-on-glass products, Loctite 3882 electrically conductive epoxy adhesive can replace solder. The single-component, silver-filled epoxy cures in 24 hours at 23°C or in one hour at 110°C and can be dispensed by means of a syringe or by stencil/screen printing.The material is both electrically and thermally conductive and develops strong, durable bonds between many materials. These include metals, ceramics, glass, laminates and molded plastics. Thermal conductivity is rated at >1.5W/m°C.

Then there's this site.

Electrically Conductive Adhesive

A clip from that page...

However, their disadvantages have restricted commercial applications: electrical conductivity is lower than metal alloy solders, conductivity fatigue is a problem (elevated temperatures, high humidity and wear-and-tear in use can impair conductivity), the connections can fail reliability tests, there is limited current-carrying capability, and the impact strength is poor.

Stick to solder if you don't want a ton of headaches!

@Peter Lagus 091618 posted:

Lead based solder has been outlawed in Europe for electrical assembly. Instead the industry uses conductive epoxy. Has anyone tried conductive epoxy to connect feeder wires to rails instead of soldering? If it works well this would eliminate the problem of ugly solder gobs on the side of rails and also no more melting of ties on flex track due to overheating the rail.

I'm afraid intelligence has been outlawed in Europe along with their lead-based solder.

If you want to avoid ugly globs of REAL solder on the sides of your rails, may I boldly go where no man has gone before and offer this respectful suggestion?...................  LEARN TO SOLDER!!!

Learning to solder is not that hard to do.  All it takes is some studying of the basics and a little bit of practice.  I can solder 24 ga. feeder wires to the sides of Atlas code 55 N-scale rails and melt NO ties, and have NO ugly globs of solder.  Zero.  Nada.  Zilch.  None.  And using cheap-***ed soldering equipment to boot.  I have NO problems at all.  You'd be hard-pressed to find my soldered feeder wires.  As a matter of fact, even I have problems finding my own soldered feeder wires! 

That's my mileage, yours may vary.  

I soldered to the bottom of the rails.  But I have a hard time finding the locations when I want to tap in.

Being able to easily find the solder location would be a minor benefit to the ugly glob technique.   Course you could always put some scenery or ballast therd.

If you have purchased anything with a circuit board in it over the last decade and a half, it has a RoHS compliance label somewhere on it.  Lead free solder.  You can chose to buy a coil of that instead of the 60/40 solder we have used for decades. 

If you continue to use non-RohS solder,  don't sell your layout in Europe!

WRT conductive epoxy, glues soften when heated and there's nothing like a short to generate a lot of heat.  Not appropriate for layout use.

This conversation needs a recommendation from someone about what lead-free solder to use to attach wires to track. I don't have any experience, I still use lead-bearing.

Lead free solder will work but the melting temperature is higher than common 60-40 and the flux is not as effective. I have a roll of it and it stays in the drawer.

I believe lead based solders are banned for use in plumbing applications in many localities even in the US. 

Pete

Lead free solder is a mixture of Zinc and Antimony, (Plumbing). There is a (lead free) flux, (Soldering paste, applied with a brush), that is to be used with Lead free solder.  Lead free, Plumbing connections, tend to require slightly more heat (Those blue propane torch canister, may have to be replaced with map gas, Yellow canisters),  and patience.  Copper pipe plumbing, has been replaced, recent years, with PEX, tubing, and solder-less connections.  

1.  Apply rosin core electrical solder to the wire end to be solder.  (Called tinning)

2.  Apply solder to the side or bottom the rail. Cleaning the rail, try not to remove the galvanized coating on the steel rail. Solder should flow evenly, and silver the side, or bottom, of the rail.  

3.  Connect the two tinned surfaces, apply additional solder if required. 

4.  May require a higher energy soldering gun.  Be careful, don't melt the plastic ties. 

Cleaning with a small file or screw driver. 

Holding the wire in place with a small screw driver. 

Apply solder, holding the wire, with the solder gun tip. 

Hold the wire again, with the small screw driver, until the liquid solder sets/hardens. 

Complete with a mechanical test:  Try to pry the solder loose from the side of the rail.  If the solder joint pops-off the rail, clean and repeat.  Have fun Mike CT. 

Pictured are the two input rail sections, used for auto-non-derail, on a Ross switch already install on a Fort Pitt switching module.  

I've used lead-free solder, and it's not nearly as "user friendly" as my gold standard, 63/37 Rosin Core solder.  I also have several rolls of lead-free solder, they all live comfortably in my closet.  I suspect they'll live out their life right there, just picked up another pound roll of the 63/37 solder.

This thread lead me down a rabbit hole reading data sheets, research reports, and lead vs. lead-free solder discussions (some of the blogs are humorous rants).  Take-away from the data sheets and research reports on conductive adhesives:

1.  The adhesives are designed for electronics - circuit boards, etc.  They are widely used for chips on glass and flexible substrates - LCD, wearable electronics, etc.  They are more expensive than solder.

2.  Resistance at component connections (glue points) is a factor and a) a long hot cure is best for low resistance, and b) the joint can deteriorate and increase the resistance over time.  Joints with tin, copper, and nickel substrates are more likely to deteriorate (what are our rails made of?).  Joint preparation (cleaning) is critical.

3.  The data sheets do not mention use of adhesives for high current applications.  Using adhesives for track power connections with room temperature cure is the wrong use of this goop.

The solder wars boil down to us guys who spent years using tin/lead solder and the younger folks who learned using lead-free solder.    The lead-free guys developed their soldering technique without discovering how much easier it is to use tin/lead solder - particularly on applications other than circuit boards.

(then there is my upcoming copper plumbing project - I guess I'll have to learn to use lead free for this)

@Tracker John posted:

 

(then there is my upcoming copper plumbing project - I guess I'll have to learn to use lead free for this)

Handy tip for soldering copper plumbing with modern day lead-free solders and pastes................

Clean the living bajeebers out of every surface that the solder is supposed to touch.  Get those special wire brushes made especially for cleaning the insides of fittings and the outsides of the pipe.  Brush that copper super-shiny until it glows in the dark.  Then brush a little more just to be double sure.

That's the BEST way to insure a leak-free joint the first time around.  Nothing worse than turning the water on, then having to go back and fix some leaking joints because they weren't quite clean enough.

Don't ask me how I know.  

solder with lead is only banned in Europe for the application for drinking water

here in the Netherlands you can buy both with and without lead

a good job starts with good tools, a soldering station with 50watts or more is best to use

the more watts ,the quicker you have heated up the solder and less damage to your plastic ties

and a proper cleaning helps (is a must)

Cor

@moonlicht posted:

solder with lead is only banned in Europe for the application for drinking water.  Cor

Thank you.  It is also true in the US.

@Tracker John posted:

This thread lead me down a rabbit hole reading data sheets, research reports, and lead vs. lead-free solder discussions (some of the blogs are humorous rants).  Take-away from the data sheets and research reports on conductive adhesives:

...snip...

Bottom line?  It ain't for attaching drops to model train track!

Thanks to all for illuminating responses. I can solder OK I just hate doing.

You'll hate that alternative more when you have to clean all that gunk off the rails and then solder anyway!