Cold Solder? Conductive Epoxy?

here is some for you!

http://www.masterbond.com/prop...fznMYCFcwXHwodfJwFoQ

Alan

good luck with your repair

I found the cost....$40 for about 40 grams, but....a lot less in a little epoxy type

syringe, for "silver conductive epoxy", is $12.  With "silver", no surprise, but what

I can't find is a local source for something I needed this morning.  No bigbox

store...Menard's, Loew's, Home Depot, nor auto or electric motor shops (that I hit)

had it.  The places with the websites don't say who their retailers are.......

These products are by no means a panacea.  They don't carry any significant current as the junction resistance is much too high.  It also has a short shelf life and is not cheap.

Silver Epoxy Adhesive

CircuitWorks® Conductive Pen Dispenser

I cant say new stuff doesn't work, but the old paste didn't work well at all for me, let alone for long term.

 Many years ago I used a copper based "repair paint" on the rear window de-icer/defogger for a couple of automobiles. That was better, and I did a couple low power board repairs with it.

 It did the window de-icer repair in a few layers and it was thick enough to actually created a cool spot on the window element.

What kind of amps does the connection pull. 

I'll continue to use my soldering iron and fine wire for PCB repairs.

   Lots of reasons I don't see a "save all" "cold application" conductive material happening soon. Wire and solder is definitely the way to go if at all possible.

 The traces I repaired only carried logic signals, no heavy current. I thought the windshield repair story was more relevant due to the higher amperage pulled.

I've had fun with my fair share of "spaghetti boards"

 On occasion I would run into a board coating that you could scrape the trace coating off of, but around the trace, the "coating" or adhesive would melt, flow, and mix with the solder/flux creating a gummy mess. The flux just couldn't keep up with cleaning.

 Or the trace would lift from the board immediately.

Even at low heat and working component holes, some traces would lift. Short bursts of high temp, sometimes worked better because the goo didn't have time to flow into the work.

I hated those boards.

  Coated traces that did lift a little, sometimes could be pushed back onto the board by waiting a split second for solder to harden, then while still hot, pressing, holding it with wood/stainless. The end result was it often held, once the coating had cooled.  

 I think the traces on them where applied by embedding them in a film then transferring it to the board, rather than the traditional etching "acid bath".

 I thought the reasoning was lower production costs for small boards, or maybe to make repair difficult, encouraging more small board purchases.    

 .    

I've seen the boards that they actually "press" the traces on and not do the standard board fabrication.  My understanding was it was for prototyping, but I never directly dealt with them.  Other than the couple of weeks turn-around time, getting a handful of 1" x 2" boards for $36 total is good enough for my uses.

Solder and wire is just great, if you have room, and your space is not surrounded by

a plastic body that you don't want to tear apart.  Now if I try to run an iron in there,

will it burst into flame, or will it just melt down into a puddle?  I have soldered extenders on the wires to reach in there (room for that) but stick an iron in there?

Others can do as they wish, I am looking for a cooler solution.  This sounds like one,

IF you could find the danged stuff.

I solder inside plastic bodies all the time, I try not to poke the soldering iron through, it makes the exterior kinda' ugly.

Have you seen this Conductive silver pen?  Maybe it will suit your needs.  I have used this. It works well and conducts very well.

http://www.mcmelectronics.com/product/200-175

?????? Its called a Dolphin splice connector. Just squeeze one flat.

A very rugged shell too.

Not being known for my patience, and faced with a weekend during which nothing is

open or can be found, I dug out an old pencil soldering iron I had not used, literally,

snce the 1960's.  With a little clean up and tightening, and with the use of plastic

clampes on the modlel to make sure wires went where I thought they did....first tries they did not, but I got this running as a test, followed all the rules about tinning, and,

soldered back on (by just delicately holding a drop of solder on the tip) the two wires that came off during handling while I was  stretching the frame of the Industrial Rail trolley for the shortened gas electric body. Wires were long enough, but broke away, anyway.  Next trolley will be extended a LOT longer, for a full Walthers body, so wires

will be soldered BEFORE reassembly, as will details to the tinplate Walthers sides.

No room for needle nose?

Can you get a small nut & bolt up there?

  If so you could maybe get a shaved down terminal, from a mini terminal block in there.  

 I've sawed off and ground excess down to a single terminals from blue plastic terminal block seen on circuit boards.

  I used one larger nylon one, hidden behind the tanks just above the drivers on an 0-4-0 mpc dc to ac conversion. A sloppy, loosely added headlight wire, drooped and got cut by a flange but wired ac, the light still worked rubbing on the wheel ..a little anyhow 

The body and frame held it from twisting as I tightened the set screw for the splice.

For tight spaces, I use these many times.

Micro-Mark has a page of clamps, and more not grouped together, so I am not now

looking at them all, but I use those plastic clamps, and was in M-M looking for smaller

plastic ones, maybe one inch, vs. those over two inches. I needed the wires held

temporarily while item was test run, to make sure locations were correct.  And since

it is "hot" and running, I want plastic.  The catalog has the same problem big box

stores have....the logical stuff is not all grouped together.  Just did a run in one this

morning and...they had moved it.  Not the first time for that to happen...and, of course, nobody ever to ask.

Most train shows have a decent selection of these kinds of tools, I believe I picked some of these up at Allentown a number of years ago.

Yup, I have seen them in a lot of shows...and have some...but another of Murphy's

Laws, like with the c. epoxy is:  when you need it, you don't have it, and can't find it.

In my haste to find the above stuff ("silver" conductive epoxy...some has no silver, so

watch it..dunno how any of it works) locally (har de har....can't even find an LHS), I

was finding so little information on the general web, I did not even look at the Bay.

Guess what?  Type in that title and you can find a washtub of the stuff...and, as with

trains, at wildly different prices.  Caveat emptor   Well, too little, too late for this project.

If somebody uses this in a train board or other application, let us know if it really will

do as advertised.

 While not ideal, maybe if you can get a twist or two into the wires for a connection. An epoxy would hold it in place. Rubberized epoxy could isolate, and/or liquid electric tape to finish it off.(I really like liquid electrical tape)

Hmmm....another unheard of aid to keep down blood pressure..."liquid electrical tape",

I just took a note.  Thanks!   May be what the rice chewers slathered over the wiring on this Industrial Rail chassis.   (That looks like a relative of rubber cement?)

Just one wire and tiny peg sticking up.  Pencil iron and a miniscule drop of solder.....c-a-r-e-f-u-l-l-y positioned, a risk I didn't want to take, worked...Murphy took the weekend off.  It is now done...I have an Industrial Rail gas electric.

I love liquid tape, but I rarely use it for insulation.  It's perfect for blocking back-scatter light from lighting installations.