Photo Etched Turnout Details: N Scale Code 40 No. 10 Turnout

[railnerd]

Have you considered solder paste and a hot soldering station?

-Dave

[peteski]

When soldering, if enough flux and heat is applied, and if the soldered parts are in contact with each other, you should not need any pressure applied with the soldering iron.  It would also make sense to use a larger tip with flattened end.

The flux should be liberally applied. I would use paste flux, or the Superior flux gel recommended by @robert3985 .  Then apply some solder to the iron's tip (for better heat transfer) and touch it to the soldered item, then wait. As it heats up you should be able to put some solder wire against the joint of the 2 parts.  Once the soldered item is hot enough, the solder will start melting and wick into the joint.  It is similar to sweating copper water pipes.

Another alternative would be to use resistance soldering unit, but you sill need plenty of flux.

[CRL]

The biggest mistake I made when first learning to solder was trying to work with a dry tip on the iron. If you don’t wet the tip with a drop of solder, you won’t get a fast heat transfer and will risk warping the part, or if soldering flex track, melting the ties. The drop of solder provides a very effective heat transfer very quickly.

The second mistake was not using flux. If you use a wet tip and flux, even an idiot like me can make good solder joints.

[Chris333]

Did you try soldering that with a propane torch?  I have a small one that I use, but those ones for soldering pipe will work.

[ednadolski]

@CRL  yep, I've coated each side of each layer with the flux before slipping it onto the stack.  It seems to me fundamentally like a heat transfer problem, in order to get the solder to flow into all the areas between the layers.   I've been using the lead-free solder, which inherently has a higher melting point, so that probably makes it a bit more difficult.

Have you considered solder paste and a hot soldering station?

I'd need to figure out the right amount of solder to use and a uniform way to apply the heat.  Do you mean something like these:

https://www.amazon.com/gp/product/B001S32FUG/ref=ox_sc_act_title_6?smid=A1NX1V2G2FJBCX&psc=1

https://www.amazon.com/gp/product/B01MR2IWBN/ref=ox_sc_saved_title_2?smid=A32FL4O5Z8G8DU&psc=1

https://www.amazon.com/GOLDNCONN-Pencil-Welding-Soldering-Lighter/dp/B06Y2J74T8/ref=sr_1_15?dchild=1&keywords=micro+solder+torch&qid=1623017957&sr=8-15

I've not used either the station or the torch, tho those look like they should have enough control to avoid overheating the parts.

Ed

[peteski]

@CRL  yep, I've coated each side of each layer with the flux before slipping it onto the stack.  It seems to me fundamentally like a heat transfer problem, in order to get the solder to flow into all the areas between the layers.   I've been using the lead-free solder, which inherently has a higher melting point, so that probably makes it a bit more difficult.

Both CRL and I mentioned having some melted solder on the (freshly cleaned) tip.  Wet tip. That will greatly aid in the heat transfer. The flux actually aids in heat transfer too. Size of the tip and iron's wattage matter too.  Also, are you using just plain pencil iron (no temperature adjustment), or a temperature controlled iron?  Or are you using a soldering  gun? 

[ednadolski]

Both CRL and I mentioned having some melted solder on the (freshly cleaned) tip.  Wet tip. That will greatly aid in the heat transfer. The flux actually aids in heat transfer too. Size of the tip and iron's wattage matter too.  Also, are you using just plain pencil iron (no temperature adjustment), or a temperature controlled iron?  Or are you using a soldering  gun? 

I'm using a Weller ESD51 controlled temperature station with a 1/16" ETAA chisel (flat side) tip, with the station set to 750 degrees F. (pretty high, actually) and the tip freshly wetted after cleaning with at tip tinner and also a Hakko 599B tip cleaner to remove any oxidation/flux build up on the tip.   Flux is the SuperSafe #30 gel (the one that @robert3985 often recommends).  The heat transfer is quite sufficient for soldering to a single solid piece of metal such as a rail or PCB copper cladding.  In this case however, the challenge comes in trying to get enough heat transfer across multiple layers (i.e., four) of metal: each metal layer has to have sufficient mechanical surface contact in order to allow enough heat to flow thru it into the adjacent layer.  However that does require some nonzero amount of mechanical pressure from the iron in order to press all the layers into contact, since each individual layer is not going to be perfectly flat and (cumulatively) will have some inevitable surface variances that will otherwise inhibit the flow of heat.  That, plus each individual layer will behave in some sense like a heat sink, in that the thermal conductivity within a given layer will (being solid metal after all) be considerably higher than the thermal conductivity between any two layers (esp. with a layer of flux in between).  The net result is a significantly lossy thermal path, by the time you get from the contact area of the source to the lowermost layer (which by virtue of having the most mass is also in effect the largest heat sink of the path).

One might try to 'cheat' the process by using an excess layer of wetting solder on the tip of an iron, and try to position it in such a manner as to (hopefully) contact all four layers at once.   This however is easier said than done, since the shapes of the individual layers do not necessarily align in a favorable manner (and pressing too hard with the tip can very easily deform the metal, as you can see in the pics).  Since the heat flow is still rather poor, the outcome more often than not is that this just will leave excess blobs of 'cold' solder behind on the parts.

So it seems that a successful approach is probably going to be something that can heat most/all of the assembly at once, like the torch or hot station as has been suggested.  At this point it is a bit of an academic exercise, since these parts do need some dimensional modifications in order to produce a usable frog (most significantly, the second layer from the bottom should probably be a half-etch thickness in the flangeway area, if I want the NMRA gauge to pass thru it properly).   The other thing is to get a better assembly jig, as the plywood one in these pics is not something I would expect would hold up too well under a torch flame </haironfire>.   

Ed

[Chris333]

Crap the one I have is Butane not Propane.
https://www.harborfreight.com/butane-micro-torch-63170.html

[ednadolski]

Crap the one I have is Butane not Propane.
https://www.harborfreight.com/butane-micro-torch-63170.html

It says the flame is 2000 degrees F..... guess I would need some kind of ceramic/tile for the assembly jig instead of the plywood 

Edit: but what is the melting point of nickel silver, anyways....?   


Ed

[peteski]

I did not realize there were 4 layers to solder.  That does create a bit of a problem using soldering iron.  750F also seems like it would be sufficient, although I would maybe try going up to 800F so enough heat penetrates to the bottom layer. Maybe use larger tip so there is more heat transferred. With those temperatures the wood base will likely starts turning onto charcoal.

How about using solder with lower melting temperature?

Torch might be a viable option, but will the wood base be sturdy enough to survive the torch flame?

[peteski]

It says the flame is 2000 degrees F..... guess I would need some kind of ceramic/tile for the assembly jig instead of the plywood 

Edit: but what is the melting point of nickel silver, anyways....?   

LOL!  That web page also shows temperature range 120° to 2100° F.

[Chris333]

You only hold the flame till the solder flows not till the house burns down    And is cheap nevermind...

[Chris333]

More precise. This is the actual one I have:
https://www.homedepot.com/p/Bernzomatic-ST2200T-Butane-Micro-Torch-330194/100564678

[Lemosteam]

If you can find some low temp solder paste, this can be done in an oven with a nice even heat that will let the solder flow between the layers.

Trick is you will need to apply the paste and clamp the parts together or the solder will be like wet ice and the parts will skate.  Suggest adding a very small pin hole through all of the parts for some 0.015" PB wire to act as an alignment pin that can be snipped off after the assembly.

[svedblen]

Probably a stupid suggestion, but can’t you solder one layer at the time?