I am looking for a how to on soldering track joints.
My layout is an older N-Scale with sectional track and i will be upgrading to flex track in places. I would like to solder the joints to increase reliability.
Tips, online instructions, etc woudl be appreciated.
Thanks,
Kevin
I use a 140/100 Weller soldering gun rather than a soldering iron for soldering track. Trust me, it’s worth the investment.
I brush flux paste on the joint and tin the tip of the soldering gun first. I touch the tinned tip to the outside of the rail at the joint and the flux makes the solder flow instantly. Hot and fast; make sure you don’t linger or you’ll melt the ties.
Good luck.
It really pays to thoroughly clean the sufaces to be soldered,then do like Dave says.
Once you are sure your trackplan is a go, lay out the most inaccessible and potentially complex spots first, particularly if it means having to put a lot of your weight up and over the layout front. You don’t want to be working over nicely tuned trackage.
Rule #1, avoid gluing turnouts into place. Keep them tacked into place so that they don’t creep and don’t rise and dip anywhere as weight traverses them. Never solder a turnout.
Rule #2, lay your curves where you know you’ll have to have them, and place tangents in between. That’s the order. The secret is to lay two or more pre-soldered sections of flextrack to form your curves. I hope you can begin to see that you must have this carefully mapped out with figures because the tangents must meet the curves with no kinks…or you’re in for some rude surprises, particularly with larger steamers. In fact, it is that much more crucial in your scale.
a. lay the flextrack sections on a flat surface and solder the rails, making doubly sure they don’t squirm as you apply the soldering iron. Try spiking the rails nearest the joints so that you can apply a bit of tip pressure where you need to. Then, you can bend to the curvature you need while being reasonably confident that the rails will not develop a kink.
b. Get a clean tipped and hot soldering iron ready, a blade or fine point is best. Thirty watts is all you need, but some like much more. Place the rail ends flush with each other…use a resin paste if you wish, although most hobby solders come with a resin core. I use acid flux because it works best…just remember to wash the completed joint with water and soap, then rinse and blow it dry with your pursed lips. Use the hot blade to pre-heat the rails for a
Thanks for all the feedback.
Could someone elaborate of the difference in technique for using high wattage vs. low wattage irons?
Thanks again,
Kevin
Hi Kevin,
I am one of those purists who disdain the use of high wattage irons. Then again I learned to solder electronics almost 40 years ago and have had a lot of practice.
You NEVER need over 40 watts to solder code 100 or smaller NS rail. If you need the gun then you are doing something wrong or are extremely fast.
The smaller iron is easier to control, easier to put the heat where you want it and does not melt the ties as easily. The best irons even have adjustable regulated heat output but that is unnecessary.
A larger iron or gun helps to make up for poor materials or poor technique. Some guns have lights in front.
Both work with good technique.
Whatever you use, just follow these rules.
Clean, oxide free parts (rail ends). Polish them if you need to. Align the ends well.
Use ONLY 60/40 electronics grade rosin core solder. Save any other grade for plumbing. Acid core is a bad idea unless you clean very thoroghly. It does not work any better, in fact it is worse in some cases and residue will damage things.
Keep your iron’s tip clean and nicely tined.
Apply tip near joint (I apply to one side of the joint against rail and joiner).
As soon as the rail is hot (a few seconds at most) apply solder to the rail and joiner near the tip. Slide tip and solder to the other side of the joint then remove both. This takes about 1 second.
Let cool and do not touch! [V] A hot joint looks just like a good cold joint.
Clean with a bit of alcohol if necessary (it shouldn’t be) and check alignment.
Done.
Good luck, proficiency comes quickly with practice.
Karl
I wonder if I could inject a related question: is it necessary to leave gaps unsoldered, and even slightly open, to allow for expansion and contraction. My layout is in an unheated basement (warm enough because the furnace is there but no doubt there is some variation). And over the years one section has definitely developed a certain waviness. It doesn’t affect operation, and I’m telling myself for the time being that it’s the branch line with rough track suitable for my shay, but it definitely wasn’t part of the plan and I wondered if there’s an obvious way of allowing for it. I hate the idea of leaving gaps.
In a word yes [:)]
You’re lucky the rails didn’t choose to expand upward, ripping out of the ties.
Never mind how I know that happens.
Be very careful! Use an approximately 15-watt iron with a 1/8 inch or so flat tip; apply the heat to the outside, and let it cap in. Just a touch - it takes almost nothing. That is to say apply the heat to the outside of the rail, and the solder to the inside just 'til it flows. Do it a couple times on scrap rail and you’ll get it.
Dang. But thanks. Is there any rule of thumb for how much gap, and how many gaps, to leave? I seem to have dozed through the part of science class where they talked about expansion and contraction.
I’m sure there are rules of thumb, but here are my thoughts…
It is alsmost never really the rail expanding and contracting on a layout that causes trouble, but just about everything under the rail moves all over the place due to temperature and humidity changes. But, since you really can’t control that, you will need some gaps in the rail. With flextrack, you need to solder the curves to avoid kinks. But on the straights you can solder fewer or the joints, maybe only every other, and leave a business card’s width of a gap. Then solder feeders such that every section either has a feeder, or is soldered to a rail that has a feeder. That might be overkill, but it will give you good reliability for the long haul.
Posters talk about high wattage versus low wattage irons. It’s not so much about the wattage as it is about the temperature. Higher wattage does not always mean higher temperature. All wattage means is the power drawn from the AC outlet.
When I worked in aerospace we used Weller soldering stations and various size tips. We also learned that it’s not temperature that gets you into trouble and melting things as it is dwell time on the joint with the heat applied. You ideally want a high temperature with a short dwell time; tip size doesn’t mean a whole heck of a lot.
Actually, the best soldering technique for soldering rail or anything small is a resistance soldering setup. The best known manufacturer is American Beauty, and MicroMark sells a couple of different outfits with different handpieces. The beauty of this method is that the heat is concentrated only at the spot being soldered and doesn’t travel down your workpiece. So you won’t melt plastic ties unless you really want to. The AB units also have a control to vary the heat available so you don’t have to use the same heat as you would for bigger connections as you would small connections.
And remember, clean your pieces to be soldered and NEVER use acid-core solder, despite what the guy says who does the Fast Tracks turnout videos. Rosin core solder and flux is the stuff to use on any kind of electrical connection.
All good info above. The article in the Feb. 2007 issue of MR written by Lionel Strang mentions many of these points and goes even deeper on the subject including melting temps and when to use silver bearing solder. He mentions using a 5 to 40 watt adjustable iron for wiring and a two setting instant heating gun for soldering track feeders. Pay close attention to the acid flux vs rosin flux issue also. You don’t want to use acid flux for electrical soldering applications. I remember my days as a soldering newbie, it wasn’t pretty. One day I finally discovered the trick and never looked back. If you aren’t sure, practice before you put the heat on something you don’t want to damage. One other tip from my experience, make sure the the wire or track you are soldering is not energized.
Ok… I am having some issues here with soldering track feeder wires, I know I am doing something stupid but it has me lost… I have only two hands so when I try to solder a feeder wire on to the track, I am holding the track and wire location with one hand but then I can hold the solder with the other and the solder iron in the same hand… How do I hold all 4 things in 2 hands and do a nice job? I know it sounds stupid… but I am having issue with this…
Thanks
You dont even need that hot of an iron, just be sure to have rails clean put liquid flux (small amount) on the rails and have your iron pre heated and touch the rail with the iron and solder till the solder flows inbetween the release the iron from the rail. this should only take a few sec as the longer it’s on the ties will melt. the other thing you can do is put alligater clips and inch down on each end of the rail that your going to be soldering so that it absorbs alot of the heat of the iron
Hold the track down with somthing, or in a vise (gently) some distance from where you are soldering. Hold the iron in one hand, the wire and the solder in the other, use your thumb with the wire, just wedge the solder between some other fingers so you can get in close when you need it. And good luck!
Clean, flux, and tin the wire and rail, before trying to attach it to the rail. Then I use allagator clips [also makes a heat sink] to hold the wire place. Applie some heat and your done.
inch
O.K. folks,
I think I missed something here. How long should I keep the soldering iron tip to the rail.
It seems to me that unless the rail is hot enough it won’t take the solder. If the tip is tinned with solder and I apply the tip to the cold rail what happens then???
Confused…thanks.
The rail gets hot, within a few (single digit) seconds. The solder flows, you get the iron out, wait a couple seconds, and you are done. A little flux can quicken the process.