It may be good to get some silver solder. I do not have any, I am still using a number of different sized Radio Shack Rosin Core solder spools I bought 25 years ago. They work fine for me for most electrical work. I have successfully repaired a number of Gilbert smoke units with the standard 60/40 solder. I also have a spool of 63/37.
The risk of using silver solder is also its benefit. It has a much higher melting point, making it easier to damage the fiber board that holds the smoke unit lugs.
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This is where resistance soldering might come into its own; it delivers the heat across the joint, instead of by conduction from the near line-contact of the wraps on one side until liquidus.
For this job the eutectic 63/37 āfast freezeā isnāt important (the wraps hold the joint positioned) so if going with regular rosin core the 60/40 should indeed work about as well.
Agree, I use the 60/40. So far it has always worked for the smoke unit repairs.
Woke,
I am by all means a model train rookie and want to be educated. Specifically I need to be educated when you say when you say put flux on joint. Is the joint another term for the wire wrap. And I should just put a layer of flux on it?
Thanks for the educationš
Bob
If itās good enough for you two. Iām sold.60/40 it is
Thanks Again
Bob
Bob, rosin core electrical solder has flux in the hollow center of the solder. For most soldering this is adequate. When I solder onto rails I also use some paste flux to coat the track surface and the wire end or the copper tie strip.
Bob:
Clean the Nichrome leads and the pin or wire youāre attaching to. There is not much scrubbing you can do in wire this fine, but do what you can. A Serious Modeler 
would have 3M lapping film in 1000 and higher grits, which would do a good job of surface prep without straining or stressing the wireā¦ wet sanding with very fine grit sandpaper may work but the backing is not as flexible.
The tail of the Nichrome winds around the copper wire: if you look up some references on wire-wrap connections (which were a major high-tech āthingā in electronics a few decades ago!) you will get an idea of what a good wrapped joint looks like, and some of the tools that can facilitate this. In my opinion the turns of wrap should be tight to the wire but NOT touching each other as laid ā you might even use the edge of an X-Acto #1 or scalpel to gently wedge the turns slightly apart. That facilitates solder wicking through the turns and bonding to the copper, providing mechanical keying as well as adhesion.
You put a drop of no-clean compatible flux on the turns area, enough to wet the whole of the āenclosedā volume and coat the surface of the Nichrome. This will encourage the molten solder to flow and give it a good bond. Without that, even if the solder has a rosin core, it may not make it fully āin thereā as it should with minimal heating time.
What Iād do is take a chip of solder and float it on the ātopā of the joint, and bring the iron up from underneath ā touch a flat side on a chisel-tip iron for more heat transfer if thatās the type of tip you have.
BE SURE YOUT TIP IS CLEAN. You clean the tip after every joint. I use bronze wool rather than a sponge to be sure any schmutz is scrubbed off, then I plunge the tip in solder paste of appropriate composition which fluxes and retains the tip in one step without excess solder running down off the tip or blobbing on it. Some people find it useful to put a heavy amount of solder molten on the tip, and transfer it to the joint that way, but unless youāre disciplined or experienced that is a royal road to cold solder joints. The likely entire history of the post-WWII United States was likely ruined by cold-soldered joints, so avoid even the chance diligently.
Hold the iron against the wraps until the piece on top melts, turns shiny, and wicks into the joint all around. 63/37 or silver eutectic (the best is a āquadā eutectic but itās a little pricy) will freeze all at once; 60/40 will sludge for a few seconds during which you must not let the joint move or twist.
Resistance soldering will be across the joint āhorizontallyā with the chip on top and circulation to the bottom. You may want to follow that up with a heavier solder bead put on with a conventional iron to ensure the greatest contactā¦
Incidentally you used no-clean flux so you wouldnāt have to rinse the joint afterward, but you should still rinse if you can ā stay away from rinsing into the wick material if you can.
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Tom and Woke,
Thanks for all your patience and education.
I now feel ready to tackle the challenge
Thank You again,
Sincerely,
Bob
PS Iāll let you know how it all turns out.
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Took my 326 apart, smoke unit registered 10 ohms, Opened the unit and got a surprise nothing like the parts locomotive smoke unit except the case. Donāt know what to do next!
Help unless your tired of helping.me I thought it would be a breeze and maybe itās still possible The wick was stuffed in the front chamber and only a divider in the rear chamber.
Not what I expected. Not even sure if itās suppose to be like that.
Thanks,
Bob
Looking at the picture below, do you have the one on the left or the one on the right? The one on the left is the original two chamber design, the one on the right is the later single chamber design. I thought all the 326ās had the two chamber design except the 1958ās with the two position reverse unit mounted to the back of the motor.
By the way, the wick you posted above appears to be threaded through the holes in an insulator box that fits in the newer single chamber design. That box cannot be used in the two chamber smoke unit.
The one on the top left with the divider in the back chamber The one on the looks for like my parts smoke unit that I had showed you the yesterday That wick is much longer than the one Iām to fix
The back chamber was empty and wick stuck into front chamber
The instructions on the PortLines site are for the two chamber, the one on the left. Either smoke unit will fit in your 326, the one on the right with a single chamber is easier to rebuild.
The smoke unit on the parts loco has top and bottom screwed on covers.
The one Iām trying to fix only has one screwed on cover.
The wick in the one Iām fixing does not go through holes, sits in chamber with horizontal bar hanging down wrapped with wire surrounded by wick.
hope this is helping and not making it worse.
Bob
Thanks,
Promise! no more questions, Iām off to port Line
Have a great weekend
Bob
sounds like the same style unit that is in my 21085 pacific. The ābarā you mention, I believe, is the insulating material that is supposed to help keep the nichrome-wound part of the wick from shifting close enough to touch the metal chamber body.
-El