Soldering rail joints

[DKS]

One thing I prefer about liquid flux over any sort of paste (aside from much easier cleanup) is that the liquid will be drawn inside the rail joiner by capillary action, which will then help draw the solder into the joint (since the liquid will prevent oxidation of the otherwise flux-free metal inside). I have taken apart rail joints soldered either with paste or no flux at all, and often found no solder inside. When using the liquid, the entire joint will be filled with solder--which is ultimately what one wants to have happen.

[robert3985]

Hey Bob, the way you are pushing that Super Safe flux, I sure hope that they pay you for your efforts! 

After an earlier lengthy thread about soldering, I did buy some of that flux and just recently I used while soldering leads to SMD 0603 LEDs.  It seems to do the job just as well as my Radio Shack paste flux.  I haven't had the need yet to use it for soldering rail or other larger metal items.

Peteski,

Hahaha...I wish.  20 or more years ago I was at a show and my hand-laid turnouts which I'd laid the previous year were self-destructing because of the acid flux I had used to make 'em,  and I got put on to the Supersafe Flux by a fellow who had a booth making and selling N-scale catenary.  He had some soldering supplies there for sale, which included Superior Supersafe No. 30 in both runny and gel, along with the tin/silver coreless solder, and he told me what I tell everybody here...it was the single best thing he'd ever done to improve his soldering success, and it made his little business viable.

So, I always put it out there.  Everybody here in Utah that I know who makes their turnouts (HO and N), who scratch builds brass/NS models, or who builds etched brass or NS kits, uses the stuff and they all agree with me...it's the best.

I really don't care if anybody has another product they like that suits them, but being a professional model builder since I was 18 years old with Battelle Labs, Thiokol and Morton, then on my own, I've used just about everything to get good solder joints.  Supersafe is the best product I've found, and maybe my boring suggestion to use it will really assist someone who is presently frustrated in their soldering endeavors.

[nkalanaga]

David:  When I use flux on rail joints I usually put it on the ends of the joiner (code 55 from ME), then put the joiner on the rails.  That way the flux is spread into the joiner, and on both the top and bottom of the rail base, with little or no visible. 

[DKS]

David:  When I use flux on rail joints I usually put it on the ends of the joiner (code 55 from ME), then put the joiner on the rails.  That way the flux is spread into the joiner, and on both the top and bottom of the rail base, with little or no visible.

That's fine for the 10% of the time I've had the opportunity to install new rail joiners. 90% of the time I'm working on rail joints in situ, with no way to dismantle the track.

[nkalanaga]

Ouch!  That would be a problem.  Mine was all new construction, so much easier.  If I have to replace a joint it sounds easier to spike both ends down solid, leave the gap, and install a new pair of feeders if needed... 

[robert3985]

Ouch!  That would be a problem.  Mine was all new construction, so much easier.  If I have to replace a joint it sounds easier to spike both ends down solid, leave the gap, and install a new pair of feeders if needed...

Whenever someone asks me about wiring, either for DC or DCC, I suggest to them that every piece of rail should have its own feeder.  Allowing rail joiners to be responsible for carrying current is just asking for problems.

How do I know that?  Because that's what my whole layout was before I decided to take the plunge and do DCC, which included a complete re-wiring, including separate 22 ga. feeders on EVERY stinking piece of rail.

Although my layout wasn't exactly "plagued" with electrical problems before the month long re-wiring project, there were portions where the engines would noticeably run slower and, there were times when rail joiners would come unsoldered, or the tips of hand-laid code 40 (which happened to be soldered to the same PCB tie) would come unsoldered due to track cleaning, getting hit in transport or for who knows what reason, and a section of track would be electrically non-functional. 

In the five years since I've done the re-wiring, I haven't had a single electrical problem with a section of track being dead due to a broken or de-soldered rail joiner.  Although I've had to re-solder a few rail joiners for mechanical reasons, the current running in the rails was never missing.

All I can say is that this is good advice, which I assimilated from many posts and articles dealing with wiring layouts, and I'm happy I did it, even though about half my track was already painted, ballasted and weathered...which really made installing the feeders a royal PITA and involved the use and modification of my resistance soldering station and a wood burning iron to melt/cut/remove under-rail Delrin spacers on already laid track.

So, anybody out there who is contemplating laying track and wiring things up...take this advice...run a feeder off of EVERY PIECE OF RAIL and do not depend on a thin little piece of NS (a notoriously poor electrical conductor) to route power to any of your track.

[Dave Schneider]

Thanks everyone for the continued hints. I picked up some liquid flux at a local electrical supply company, and it works well. Went back to the regular soldering iron. Also working well.

My plan was to add feeders to every section of track. Any thoughts on yard ladders and whether feeders are needed for every turnout (other than the obvious wire to the frog). If so, does it matter where the feeder should be attached?

Best wishes, Dave

[robert3985]

Dave,  As a "rule of thumb" I attempt to solder my feeders to every section of rail in the general vicinity of the middle of the piece.  Sometimes that's not possible, and if the rail section is short (which arbitrarily for me is 1.5' or less) where you solder it doesn't really matter from an electrical standpoint.

So, on your yard ladder, it wouldn't matter electrically where you soldered your feeders, but yes, each turnout's non-diverging stock rail should have a feeder.  Where you solder it will be a matter of what looks best, or interferes the least.  Don't rely on your rail joiners to carry electrical current.

The exception would be if you built your own yard ladder as a monolithic unit, with a single piece of rail forming the straight stock rail for all your turnouts.  That would only require one feeder somewhere near the middle of that single piece of rail.

I solder all of my feeders (when possible) to the underside of the foot of my rail, so when there's ballast, they disappear.  That's both good and bad because they are difficult to find topside if they decide to come unsoldered.  So far, that hasn't happened in five years, but I'm sure it will eventually.  I decided to sacrifice accessibility for appearance's sake.  Time will tell if that was a smart move.

I also solder to the tops of PCB ties laid specifically for attaching feeders to in some instances.  I flatten the end of my feeder with a flat nose plier, trim the end of the flattened part with a rail nipper to square it up, and solder it closely to the foot of the rail so it looks like a tie plate or some other type of rail furniture. I like to put 'em on the outside of the rail, but they work equally well soldered to the inside.  If you apply feeders for both rails this way on a single PCB tie, make sure you gap the bottom of the PCB tie also.

Have fun!  Laying track is a model railroad job that I really like...which means it's time for me to get the Emory Center Siding down and operational this weekend!

[mark.hinds]

Hi Dave,

I've always used my resistance soldering setup for soldering rail joints (since the 1980s in fact), with no problems.  Much easier than a regular iron.  The key of course is making sure the joint and the **tweezer tips** are clean.  The latter is cleaned initially with a small new metal file (pinch it between the tweezer), and touch-up is done with a fine piece of emery paper folded in half (again pinch it between the tweezer).  It also helps to wrap the emery paper around each tweezer tip to get the sides of the tips.  When adequate current flows there is a subtle vibration and faint buzzing sound which you learn to recognize.  If I tap the foot pedal and don't hear that sound, I touch up the tweezers.  You also need to make sure you have good contact between the tweezer tips and their sockets (this can oxidize over time), so clean there as well. 

I use electrical rosin core solder, sometimes with extra rosin flux, and then wipe off the excess while still hot.  Takes about a second with the micro tweezer. 

To clean the rail I use small files, although that's usually not necessary with new rail.  I wouldn't think alcolhol would do much, unless the rails are covered with oil or something similar. 

To protect the ties, I often put tweezer-type clamps on the rails near the joint, and keep handy a piece of damp paper towel in a small bowl. 

MH