Soldering question

[tom mann]

Ok, so I'm handlaying some z scale track, and I'm having problems soldering.  I don't always solder, but when I do it's a giant clusterf***.  But with z scale code 40 track, it has to be somewhat precise.

This is what I do:  I add a bit of acid flux to the PCB tie and to the bottom of the rail.  Then I place the tip on the bottom of the rail/tie intersection.  When I put the solder there, instead of flowing where the flux is, it rides up to the iron's tip.  Since the tip is on the area for too long, the flux turns black.

What am I doing wrong?  I did manage to get a couple of joints ok, and I'm happy to report that you can solder to a PCB tie that is superglued to Gatorboard.  Thank goodness @Chris333 made me 1/2 flex track so at least one side looks great.

[svedblen]

I'm far from any soldering expert, so I'm just more or less guessing: The heat spreads from the tip and in this case it reaches the solder "before" it reaches the flux. So the solder thinks it is warmer and "cosier" towards the tip and flows in that direction. Try to hold the tip on the top of the rail instead.

Just my two...

[conrail98]

Put the tip against the PCB tie and rail, as flux melts, a quick dab of solder against the joint of the tip and rail and then immediately go to the other side of the rail and apply. You only need a few seconds. I've watched at some clinics where the clinician did not applying it in the first part and just doing it on opposite side of rail from the tip, having the solder flow towards the tip for a count of like 8 or so. Here's FastTracks PDF on what I described and have seen done at handlaying clinics:

http://www.handlaidtrack.com/v/vspfiles/documents/an01.pdf#page=8

The only two semi turnouts I built, I did this. I had other issues, but the rail to PCB joint was good and required only minimal cleanup (frogs and closure rails, that's another story),

Phil

[tom mann]

I tried it again today (still recovering from a burn that prematurely ended my session yesterday) with a new tip.  I'm having much better results.  The new tip is smaller, but I suspect that it is either cleaner or tinned correctly.

I'm getting the hang of it. 

[eja]

I am sure you have seen this, but it might be new and useful to some folks who read this thread.

http://www.wiringfordcc.com/solder.htm

[Chris333]

 
I sometimes solder after the ties are glued down without problems. I lightly sand the ties and brush on flux. Then with the solder spool sitting there un-rolled a few inches. I touch the soldering iron to the solder, just enough to get some solder on it. And now touch the tie and let the solder flow up under the rail. Usually I'm holding the rail down with a file or knife blade. (or the track gauge  )

I've read where some people chop the solder into small (like 1mm) lengths so the tip doesn't soak up more than needed, but I never had to try that. Thinner solder may help too like the stuff Fasttracks sells, but the stuff I use isn't that thin really.


Nn3 these ties are glued down.

[peteski]

If both surfaces being soldered are cleaned (sanded) then I would lose the acid flux. Use flux designed for electronic circuitry (without acid).  My favorite is Radio Schack electronic paste flux.

[Doug G.]

Acid flux solder should never be needed for electronic soldering. I would include soldering track in that category.

Acid flux is only needed for plumbing - soldering copper pipe. Clean copper or nickle silver in model railroading should easily solder with rosin flux.

Doug

[Santa Fe Guy]

Tom
I agree with Pete and Doug. Cleaning both the base of the rail and the PCB is paramount. Make sure your tip is really hot and very clean. Use a small wet piece of sponge and wipe the tip of the iron every time you go to solder. I like the idea of cutting a small piece of solder and resting it against the rail and PCB intersection. A hot iron should allow the solder to float between the two. (Try gently holding the rail down on the PCB with a piece of wood like a coffee stirrer whilst you are soldering). Once that has occurred remove the iron and clean it again.
It is most important to make sure all surfaces are clean first.
Rod.

[Chris333]

I forgot to mention that I also drag the bottom of the rail along some sand paper a few times just to make sure. I used up a bunch of Atlas c55 flex by pulling the rails out for hand laying and Atlas flex has a lot of oil on it.

[tom mann]

Burn is doing better today. Thanks for asking.

Insane that there isn't a track gauge in Z. The track I put down is just fine for freight cars, but too tight for locos.

[peteski]

Burn is doing better today. Thanks for asking.

Insane that there isn't a track gauge in Z. The track I put down is just fine for freight cars, but too tight for locos.

I didn't think that a manly-man like you needed any coddling. I'm glad to hear that the boo-boo is doing better.   

I haven't done any hand-laid Z scale work so I don't know that no gauges exist. MT doesn't make one? I'm surprised that someone hasn't machined and start selling one.

[Chris333]

Thay make some Nn3 gauges tgat are hard to find. I use the MTL coupler height gauge, but it is a little loose on c40 and 55.

Tom, use aloa vera