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Flex track sections meet on a curve -- ends tend to straighten (= kink at joint). What to do?

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Posted by richhotrain on Friday, May 14, 2021 2:45 PM

crossthedog

Also, someone suggested avoiding joints on a curve. I understand that principle and will adhere to it as best I can, but I have three large curves and a piece of flex track is only three feet long, so there will be joints on all my curves, including the yard lead because that's where my curved turnouts are.

Whoever suggested avoiding joints on a curve is not thinking clearly. As you point out, joints on a curve are unavoidable with 3' sections of flex track.

At the end of a peninsula on my layout sits a 9-stall roundhouse. I have a double mainline that runs around the roundhouse. It requires 4 sections of flextrack on each mainline.

I trimmed two ties off each end of each piece of flextrack, added rail joiners, and soldered the four pieces of flextrack together for each mainline on the basement concrete floor. I didn't even need heat sinks since the ties were far enough away from the rail joints.

As I formed each of the two curves for the inner and outer mainline, if I needed more space, I clipped off additional ties, but just enough ties to enable me to freely form the curves. You want to minimize those spaces that are unsupported by ties spiked up against the rails.

Rich

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Posted by hon30critter on Friday, May 14, 2021 10:45 PM

crossthedog
buying the "good enough for a beginner" X-Tronic #3020-XTS-ST (link) online

Hi again Matt,

Don't buy the X-Tronic iron or the Weller iron. They are both crap! Pardon my English but I speak from experience. I have owned both, and thrown both in the garbage.

For the same price you can get a XYtronic like this one. It is powerful enough to solder rail joiners and it can also be used for delicate electronic work as well.

http://www.xytronic-usa.com/shop/item.aspx?itemid=253

https://www.jameco.com/z/LF-389D-Xytronic-Industries-60W-Mini-Type-Digital-Soldering-Station_2174733.html

I thought I was reasonably good at soldering, although I always had a terrible time keeping tips clean. Based on Randy Rinker's recommendation, I bought an XYtronic station similar to the one above and the difference was like night and day!!! Soldering became so much easier and the dirty tip problem practically vanished.

Dave

I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!

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Posted by wp8thsub on Saturday, May 15, 2021 1:07 AM

crossthedog
How do you hold a file against the joint while also soldering it? I think you'd have to hold the file against the outside of the rail, but that's where you want to apply the solder, nez pah?

doctorwayne
I think that what Rob was suggesting was to hold the file against the inside of the rail-joint while you're soldering the joiner in place, as it will act as a heat sink.

I hold the file against the OUTSIDE of the curve to keep the rail in alignment (i.e it's an alignment tool as opposed to a heat sink).  Note that you can feed solder into the joint prior to lining it up.  I will typically add solder first, applying heat to get it to flow everywhere it's needed.  Then I will hold a metal object like a file outside the curve, apply heat again, and gently push the rail into the correct position.  

The whole process takes longer to describe than do.  It's easy, allows you to get perfect results every time, and yet relatively few modelers do it.

crossthedog
Also, someone suggested avoiding joints on a curve. I understand that principle and will adhere to it as best I can...

There's no need to worry about avoiding joints on curves.  Once you get used to soldering and lining things up, rail on a curve can be perfectly smooth whether you manage to keep joints out of it or not.

JC Farm 1

by wp8thsub, on Flickr

Rail joints here were finished as described.  After the track is painted and ballasted, the joints disappear and all you see is a smooth curve.  This may be one of those projects you'll look back on and wonder why you were ever concerned in the first place.  It only sounds intimidating until you do it.

Rob Spangler

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Posted by doctorwayne on Saturday, May 15, 2021 1:29 AM

wp8thsub
I hold the file against the OUTSIDE of the curve to keep the rail in alignment (i.e it's an alignment tool as opposed to a heat sink).

Got it!

Your track (along with everything else) always looks great, and your attention to detail is a good example for all of us.

Wayne

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Posted by riogrande5761 on Saturday, May 15, 2021 8:37 AM

Do you solder the rails without first tinning? 

Pretty much always, unless I'm recycling track that was soldered before.

How do you get a joiner onto a tinned rail?

If there is only a thin coating, you may be able to slide it on still; if there is too much, you may have to heat the rail up first.  If I did that I'd put a heat sink on it to draw off the heat to avoid melting ties.

I have used some Radio Shack heat sinks for many years but alligator clips may do the job.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by richhotrain on Saturday, May 15, 2021 8:39 AM

Lastspikemike

My soldering station has a water well and a sponge for cleaning the tip. Someone drilled a nice set of holes in the sponge which is convenient for cleaning off excess solder and flux with a dip and twist.

I'd always understood you get the best conductivity and adhesion from soldered joints If you tinned both surfaces first. Do you solder the rails without first tinning? How do you get a joiner onto a tinned rail? 

I stopped using a wet sponge when it started destroying the tip on my soldering iron. I started using a brass wire ball that you jab the soldering iron tip into. Works like a charm and no more ruined soldering iron tips.

As far as soldering rail joints, I just tin the soldering iron tip and then apply solder to the rail joint by coating over the rail joiner.

Rich 

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Posted by Overmod on Saturday, May 15, 2021 8:42 AM

Lastspikemike
I'd always understood you get the best conductivity and adhesion from soldered joints If you tinned both surfaces first. Do you solder the rails without first tinning? How do you get a joiner onto a tinned rail?

This is why the Lord invented good no-clean flux.  It makes it just as easy to get two adjacent surfaces to 'wet' with solder as two surfaces alone before assembling them for fusion.

With wires, we pre-tin to ensure full coverage and to get enough in the joint to fill between strands and overcome any issues with clean metal when high heat can still be applied to the components.  There is no particular need to do this on a rail joint, where gravity assists the feed; a good liquid flux excludes air and readies the surface, and adding the solder as 'chips' just above the junction of the top 'curl' of the joiner and the rails gets it to melt and be drawn into the joint nearly as quickly and effectively as 'tinning' could do, and better than if melting off the end of a wire or stick of solder stock.

It would be difficult to tin a joiner effectively and still have it work as desired.  It would be difficult to tin rails and then get the joiner to 'spring' enough to go over the solder.  Technically with resistance or laser soldering you could arrange to get the joiner on one 'pretinned' rail which was hot enough to have the solder at liquidus, then heat the other pretinned rail the same way to make the joint, but this is an awful lot of expense, burn risk, etc. to get the same joint integrity as a bit of no-clean.

Tinning your feeder wires remains a wise approach.

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Posted by riogrande5761 on Saturday, May 15, 2021 8:42 AM

hon30critter
Don't buy the X-Tronic iron or the Weller iron. They are both crap! Pardon my English but I speak from experience. I have owned both, and thrown both in the garbage.

wp8thsub
I do all my track soldering with a cheap-o Weller iron I picked up at the home center.  Considering this option has worked for me for around 40 years

As Rob has noted, the inexpensive Weller iron is fine and not crap.  I bought one about 6 years ago and it's worked just fine.   Looks like experience varies.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by richhotrain on Saturday, May 15, 2021 8:43 AM

riogrande5761

Do you solder the rails without first tinning? 

Pretty much always, unless I'm recycling track that was soldered before.

How do you get a joiner onto a tinned rail?

If there is only a thin coating, you may be able to slide it on still; if there is too much, you may have to heat the rail up first.  If I did that I'd put a heat sink on it to draw off the heat to avoid melting ties.

I have to say, I have never heard of tinning the rails. I always understood that you just should tin the soldering iron tip before attempting any type of soldering task.

That said, I do tin the ends of feeder wires or wiring from signals.

Rich

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Posted by riogrande5761 on Saturday, May 15, 2021 9:28 AM

richhotrain
I have to say, I have never heard of tinning the rails. I always understood that you just should tin the soldering iron tip before attempting any type of soldering task.

Same.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by wp8thsub on Saturday, May 15, 2021 10:10 AM

richhotrain
I have to say, I have never heard of tinning the rails.

Same.  I never tin the rail first.  A properly prepared joint doesn't need this step. 

Rob Spangler

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Posted by Overmod on Saturday, May 15, 2021 10:17 AM

Cleaning and tinning the tip is a completely different thing.  Heat transfer from the tip needs to be as immediate and complete as possible; coverage of the liquid solder needs to be as smooth and, frequently, 'capillary' as possible; it's important not to starve part of the joint of solder flow, or have part of it start to 'freeze' before expected (if you're not using eutectic solder).

A plated tip is supposed to accomplish some of these things whether well-wetted with solder or not.  Problem is that as the plating wears or is abrasively cleaned, it becomes harder to 'wipe clean' and more inclined to hold dirty or oxidized material.  At some point, especially with certain tips from places that value price over plating integrity, the tips will wear to the point their base metal (usually copper or a copper alloy) is exposed.

Now copper is a good conductor of heat, but copper oxide less so, and hot copper loves to oxidize and corrode in a variety of ways, none particularly conducive to soldering ease.  What you want is to clean and burnish the copper, and then seal the 'pink' metal with a thick film of solder metal before it has even a whisper of a chance to start oxidizing materially.  Then keeping this film maintained with "regular tinning" gives you all the advantages of a plated tip without replacement cost.  (But the moment any copper gets exposed, you may have to re-clean and then re-tin the bare patches...)

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Posted by richhotrain on Saturday, May 15, 2021 1:24 PM

Overmod

Cleaning and tinning the tip is a completely different thing.  

Did someone contend otherwise?

Rich

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Posted by 7j43k on Saturday, May 15, 2021 5:23 PM

Overmod

 

A plated tip is supposed to accomplish some of these things whether well-wetted with solder or not.  Problem is that as the plating wears or is abrasively cleaned, it becomes harder to 'wipe clean' and more inclined to hold dirty or oxidized material.  At some point, especially with certain tips from places that value price over plating integrity, the tips will wear to the point their base metal (usually copper or a copper alloy) is exposed.

 

Huh.  I've got an iron with a Weller 50W #37 screw in unit.  Nice large head.  I bought it maybe 40-50 years ago--sometime in the last century.  It's got the original plated tip, in fine form.

I've cleaned it with wet paper towels for about forever.

I DON'T let it get too hot too long.  If it's going that direction, I unplug it, and cool it down by wiping with, yes, wet paper towels.

Ed

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Posted by crossthedog on Saturday, May 15, 2021 5:27 PM

Guys, here's what the local hardware store had. Someone here told to make sure the flux I bought was not acid but rosin. Maybe I misread, but in the store, the rosin/acid issue seemed to be around the solder, not the flux. I bought rosin-core solder, and I got the flux shown below. Did I get the right stuff? My thought is, the hardware store stocks soldering stuff for electricians and plumbers, not modelers.

Also I picked up an 80-watt Weller iron. Tip seems too big now that I look at it.

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by richhotrain on Saturday, May 15, 2021 5:33 PM

crossthedog

Guys, here's what the local hardware store had. Someone here told to make sure the flux I bought was not acid but rosin. Maybe I misread, but in the store, the rosin/acid issue seemed to be around the solder, not the flux. I bought rosin-core solder, and I got the flux shown below. Did I get the right stuff? My thought is, the hardware store stocks soldering stuff for electricians and plumbers, not modelers.

Rosin core solder is just that. An inner core of rosin with a solder jacket around it. Hard to tell from your photo, but the flux should be rosin flux, not acid flux. Yes, there is flux in the rosin core solder plus a separate flux applied beforehand to facilitate the spread of the rosin core solder.

Rich

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Posted by York1 on Saturday, May 15, 2021 5:35 PM

.

York1 John       

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Posted by richhotrain on Saturday, May 15, 2021 5:38 PM

It looks like you will be OK with that jar of flux. It is acid-free. Here is what the marketing pitch says about it.

Nokorode Regular Paste Flux is a lead-free, all purpose, soft soldering paste flux ideal for use with 95/5 and other common solders. Nokorode special oil base protects the solder joint against corrosive attack. It cleans and fluxes all at one time.

Features

  • Cleans and fluxes in one operation saving time and money
  • Flows smoothly into even the smallest cavity
  • Multipurpose for use with 95/5, 60/40, 50/50, and 40/60 solder
  • Lead free and acid free - safe to use on potable water systems
  • Special oil base protects the solder joint against corrosive attack

Rich

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Posted by Bayfield Transfer Railway on Saturday, May 15, 2021 5:57 PM

You don't need resistance soldering to solder.  I use a Weller 23 w iron and it works just fine.  Keep the tip clean, retin it every time you use it, scrape the rail where you are going to solder (it helps).

Get some junk track and practice.  You will never be sorry.

Also, for the record, last layout, every piece of rail either had a feeder, or was soldered to a rail that had a feeder.

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

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Posted by richhotrain on Saturday, May 15, 2021 6:00 PM

Bayfield Transfer Railway

Also, for the record, last layout, every piece of rail either had a feeder, or was soldered to a rail that had a feeder. 

YesYesYes

Rich

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Posted by gmpullman on Saturday, May 15, 2021 6:11 PM

Nokorode data sheet for #14000 says "NOT for electronic use"

APPLICATIONS: Nokorode® Regular Paste Flux can be used with 95/5, 60/40, 50/50 and 40/60 solders. It can be used on all solderable metals including copper, tin, zinc, nickel, and sheet lead. Do not use on stainless steel, aluminum or magnesium. Not recommended for electronic use. 

I would say it is for plumbing and sheet metal.

https://tinyurl.com/28pwz67a

 

https://rectorseal.com/nokorode-regular-paste-flux-group/

In my 65 years I've never used lead free solder, either. I don't know how much luck you're going to have with that. What diameter is your solder? Most of my layout soldering wotrk is with .032 and .020 solder. For decoder and PC work I use .015.

95/5? For plumbing.

https://www.oatey.com/products/oatey-955-lead-free-plumbing-wire-solder-216233657

 

Good Luck, Ed

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Posted by richhotrain on Saturday, May 15, 2021 6:17 PM

Ed, I agree that rosin flux would be best, but since his flux is lead free and acid free, wouldn't it be safe for soldering rail joints? You would not want to use it though on electronics boards.

Rich

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Posted by crossthedog on Saturday, May 15, 2021 6:45 PM

What's a flux brand you guys use? I could just look around until I find the exact stuff. And solder.

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by Overmod on Saturday, May 15, 2021 6:52 PM

Acid flux is a NO NO NO.

Zinc chloride is not far behind.

Rosin-core is nifty but in many cases you need more 'flux action' than that tiny dried-up paste provides.

DO NOT USE PLUMBER'S ANYTHING.  Plumbing requires aggressive flux to bite and clean large areas of pipe and fittings.  The solder is the antithesis of what you want for most fabrication or electronics work -- the alloy is purposely made to stay 'sludgy' as long as possible so wiped joints settle in to be water or pressure tight.  No one cares if the pipes wind up stained or blotched and difficult to clean afterward.

What I advise is finding a good solder specialty provider (there are several) and getting a liquid no-clean flux -- these come in greater and less activity; you won't need high activity (which sometimes includes that zinc chloride corrosive).  A small bottle of good no-clean will last a long time in this hobby.  In the meantime here is a link to the SRA store Ed quoted in his post (he uses their #135 rosin paste flux).

You may still want to clean the joint after "no clean" flux has been used, but it won't have the nasty issues that acid or the wrong kind of rosin blobs have.  There are special flux cleaners.  Most of them are chemically awful.  I'm not going to be Nanny and say stay away, but know really, really well what's in them and how to use them right before you open them up.

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Posted by Overmod on Saturday, May 15, 2021 6:55 PM

richhotrain
Did someone contend otherwise?

No, and I'm not being argumentative.  I just want to establish that tip hygiene is different from 'tinning' wires and parts prior to assembly.

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Posted by gmpullman on Saturday, May 15, 2021 8:06 PM

 

crossthedog
What's a flux brand you guys use? I could just look around until I find the exact stuff.

IF I'm not mistaken I put a link to the flux I find to be very good in my first reply on page 1. Maybe you didn't like that stuff?

https://en.wikibooks.org/wiki/Practical_Electronics/Soldering

For years I used 60/40 for electronic work. I liked it fine. Then when eutectic 63/37 was deemed preferable I switched to that which took me a while to get used to. So for someone just getting started to try to solder feeders and joiners to rail with lead-free 95/5 would be a real challenge.

richhotrain
but since his flux is lead free and acid free, wouldn't it be safe for soldering rail joints?

If the manufacturer states "not recommended for electrical work" that's enough of a suggestion for me to steer clear.

Kester is one of the best brands out there, 63/37 is a good all-around alloy for wiring and electronics. .031 is a handy size but if you get into finer work, say on PC boards or decoders you might want to look at some .020 even .015.

https://www.amazon.com/Kester-24-6337-0027-Solder-Alloy-Diameter/dp/B0149K4JTY/ref=sr_1_1?dchild=1&keywords=kester+63%2F37&qid=1621127299&sr=8-1

 

     


 

 

 

Regards, Ed

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Posted by Track fiddler on Saturday, May 15, 2021 9:37 PM

There will come a day again after some 40+ years gone by.  I'm writing all this solder stuff down EdYes

 

 

 

TF

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Posted by crossthedog on Saturday, May 15, 2021 9:53 PM

gmpullman
IF I'm not mistaken I put a link to the flux I find to be very good in my first reply on page 1. Maybe you didn't like that stuff?

Sorry guys, my kid's in the hospital with blood clots in her lungs so I'm distracted, and I was using my small iPhone (SE5 or whatever), which makes it hard to navigate long strings. Thanks for these links/recommendations. I'll quit posting questions until I have a chance to go back through the thread. Maybe everything I need to know is already here. Cheers,

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by York1 on Saturday, May 15, 2021 9:57 PM

Matt, don't worry about anything here.  You and your daughter are in my prayers.

York1 John       

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Posted by crossthedog on Sunday, May 16, 2021 1:10 AM

York1
Matt, don't worry about anything here. You and your daughter are in my prayers.


Thank you John, we're grateful for all prayers and good wishes. She's doing lots better, but clots are scary so we're on pins and needles. Not much to do but wait, which is probably why I jumped prematurely on the flux and solder. I hate waiting. 

But I've found decent nonAmazon prices for both of the items Ed recommended (I don't trade with Amazon). SRA's own website had the flux for the same price as Amazon and shipped it for free (!), and I found a 1lb roll of the Kester Rosin Core 0.031" solder on ebay for 2.99 and three bucks shipping, which was 25 bucks on Amazon.

If that isn't a hoax, I think I've done well. I should have done this research earlier, I've just been harried. I'll return the other stuff I bought earlier, maybe even the iron, because the tip is the size of the Gustav cannon, probably too big for trackwork. Again, I jumped quickly because it was the only high-wattage stick that I'd been able to find on a shelf locally and they only had one. I like the 80 watts but I think Hakko makes a 60-watt iron that I can find at Home Depot that has a smaller tip. And before I do that I will go back through the thread to review what you guys have said about soldering irons. Geeked 

Thanks again Ed for the particular brand and product recommendations.

-Matt

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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