It wasn’t as easy as I expected but it works. I tried a series of experiments yesterday, but first, why would you want to solder-plate tubular?
In a word, “rust.”
Resin solder provides good, if not better conductivity than the tubular tracks and it adheres to the rail–sort of. That’s the sticky point.
I figured that super-heating the entire tubular rail would facilitate the flow of resin. So I got out the propane torch and fired away.
Wrong.
What I ended up with is a blackened rail and large beads of solder (perhaps this would be a way to blacken your center rail quickly?)
Next, I got out the Weller 100-140 W soldering iron, fluxed the rail and tried painting the rail with solder. More successful but the solder still clumped.
So I got another rail to experiment on and this time I sanded it with course sandpaper. Fluxed it, then painted the rail. This time I was much more successful but it required about a half dozen passes with the soldering iron to even out the solder and a few beads did fall into the webbing and base of the rail (most were easily scraped off).
The results were still somewhat uneven (bumpy). So, I took some medium grit sandpaper and hand-sanded until it was smooth.
This process isn’t for everyone. Probably easier just buying track, unless you want some arm and hand exercise.
But the process would be good for spots of rust on sections of track already laid down; much easier than pulling the whole section and throwing it away.
There’s a question I have for you. When you perform the sanding operation, little bits of solder dust land in the ballast. To remove them before running the trains, I used a shop vac and strong magnet. Anyone else have techniques for removing tiny metal shavings?
One other question I have. Isn’t resin-solder more impervious to rust than tubular rails. I believe it is and if so, treated rails would actually be much better able to resist rust than even new tubular, as well as have better electrical conductivity.
Dave, Isn’t tinning your rails with solder ( which is lead) be considered danagers to your health [?] Tube track used to be Galvanized which is zinc plateing, to prevent rust.
I have never seen galvanized track. Since I solder all my joints, I would notice if I came across zinc, which is almost impossible to solder. Tubular track is tin-plated steel.
Solder is only part lead. Ordinary electrical solder is 60 percent tin, 40 percent lead. Plumbing solder used to be 50-50, but is now almost 100 percent tin. They took out the lead from fear that lead compounds would get into the drinking water; but I think metallic solder is not particularly dangerous. However, I use tin to rejuvenate old track.
Dave, you might try tin plating your rails with a product called “Tinnit.” It is intended for plating copper traces on printed circuit boards to make them easier to solder.
You can get it from All Electronics, www.allelectronics.com, CAT# ER-18, $5.50, and other electronics suppliers.
The stuff works at 150 degrees F. I use a rectangular glass baking dish, a “candy”
thermometer, a 1/4 in thick sheet of AL, and a hot plate.
It works well on PC boards, but I haven’t tried it for anything else.
guys, I suspect the biggest danger would be in inhaling the fumes. I “tinned my tinplate” outside on the patio.
Bob,
I did notice that tubular track is doesn’t conduct heat as efficiently as copper and that required several passes with the soldering gun.
One modification that might make the processes smoother would be to bend the soldering tip so that it wraps around the head of the tubular rail. This would presumably make the solder-painting process more efficient and effective.
Also, a true experiment would also try other solders such as silver-bearing solders, as well as different types of fluxes and different levels of heat.
Hopefully, the experiment will give pause to toy train modelers who are considering throwing away a rusty piece of track that may, in fact, be salvageable.
For track that already is laid down, to heat the rails to 150F, I would probably use my propane torch and protect the wood ties (which I installed), by placing aluminum foil between and around the rails.
Bob, you may be correct with the tin plating on the track. Some of the track I have look like a very light coat of Galvanize on it. If it is at G15 to G30, it would solder without any problems.
If the track already has tin plating, which is part lead, Dave what are you trying to accomplish by adding more lead solder to it.
I don’t think “Tinnit” would work with track already laid. The rail has to be CLEEEAN and dipped in the heated solution. Plating takes about 5 ninutes, depending on how thick of a plating you want.
For heating a rail in place, you might try running a current through it. A controlled current should be able to heat the rail just enough to make the soldering easier, but not set the ties on fire.
Tom, the track is, or rather was, tin-plated, without any lead’s being involved. The fact that it rusted indicates that the tin had worn away, exposing the steel underneath. What Dave is trying to do is to replace that tin, to cover up the steel again.
Relying on my many years in electronics design and manufacturing, solder ages and oxidizes. The oxides are not surface conductive (although the gas free area joint is still conductive). Most resins are somewhat corrosive (this is how they clean the joint being soldered). Electronics manufacturers struggle with the shelf life of tinned components (including bare, tinned, PC boards) wire leads and pads. This is why you see a lot of parts in surplus stores, the parts are no longer reliable to go through a solder pool reflow or IR reflow (surface mount parts). Most large manufacturers attempt to have processes where parts are removed when their shelf life (or time from the parts date code) have exceeded 6 months to one year.
The same issue exists for rolls of solder itself. It gets to a point (particularly with newer solders that no longer have acid core flux) where the solder will no longer flow well as the oxides that break loose and become embedded when the solder melts compromise the integrity of the solder joint.
I would caution that this use of solder could lead to problems if the layout is not used very often or is in a harsh environment (humidity, etc.).
Thanks for the info. I was very curious about the properties of solder. I don’t think that it rusts as easily as tubular but you mention oxidation. The ole brass HO rails also oxidized. Is it this type of oxidation? Or, is it more of the aluminum type? And, if so, wouldn’t track cleaners clear this up?
Also, reg. electrical wire connections with solder, are there potential problems here, even with a good joint?
As he says, “the gas free area joint is still conductive”, that is, the inside of the joint is okay. The problems are with the surface. However, I would suggest that plating with modern almost-all-tin plumbing solder would give you a new surface about as resistant to oxidation as the original, and probably much thicker, therefore with a much longer life before the steel is again exposed.
As you noted, solder does not “rust.” Yes, the solder oxidation is the same as brass or aluminum oxidation - due to exposure to the air, moisture, oils (i.e. skin), pollution, etc. An oxide is a surface exposure chemical reaction and typically does not decompose the base metal as rust does. The oxides which are on the exposed surface are not conductive (you can verify this with an ohmmeter unless you jab the ohmmeter lead into the solder joint which penetrates the oxide surface).
There are some exceptions. Silver plating or pure silver when it oxidizes is still conductive.
The internal joint such as on a wire soldered to a rail or to another wire is not affected (unless a lot of contaminates are embedded). This is the “gas free” area that I referred to. The solder joint is still conductive with aging (there are exceptions again related to contaminates in the joint). The exception is a “cold” solder joint where the solder crystallizes (instead of reforming as a metal) due to overly rapid cooling or instability in the joint when cooling. A cold solder joint crystaline structure is not electrically conductive and also allows air and moisture to penetrate, compromising the long term (and sometimes short term) integrity of the joint. This is verified by 50+ year old Lionel engines that still perform so well!
BTW FJ & G - I enjoy your many informative posts, particularly those related to your track and switch building endeavors. Your last post on this subject regarding the scratch built switch frog would not be seriously impacted by the liberal use of solder to fill in the voids in the joints. I have done this myself when I constructed HO frogs many years ago.
Thanks for the info, wrmcclellan; I may look for silver resin
also, glad you like my amateur experimenting attempts; hope to fini***racklaying this weekend, backdrop & fascia and post pictures next week. The layout will have some very novel ideas including:
industries that attach and detach from the fascia (to swap them out)
tiny blocks to keep freightcars from rolling away (since they don’t have air brakes or working handbrakes)
all handlayed track with 14-gau wire center rail
a sunset backdrop with purple mountains (backlit)
forced perspective from O to Z scale (front to back)
novel paintings in the fascia (buried dinosaurs, wrecked cars and graves, along with rock strata painted on)
switching puzzles on point to point track
a mirror that doubles the apparent size of the layout
Silver solder is an option, but it still has a zinc or tin content (bad oxides again, particularly copper and zinc) and requires a much higher temperature to melt (sometimes a torch is required).
Something I found on the web: Ag = silver, Cu = copper, Zn = Zinc, Sn = tin, Cd = cadnium. The number prior is the % content.
Basically all solders contain something undesirable. Jewelers use the hardest with the most silver (up to 95% silver) and this means nice shiney appearance and extremely high temperatures to reflow (e.g. the torch).
IT (extremely hard) 80Ag, 16Cu, 4Zn (somtimes no zn)
Hard 75Ag, 22Cu, 3Zn
Medium 70Ag, 20Cu, 10 Zn
Easy 65 Ag, 20Cu, 15 Zn
Extra Easy 56 Ag, 22 Cu, 17 Zn, 5 Sn
Easy Flo 45 Ag, 15 Cu, 16 Zn, 24 Cd
I found some additional info on lead free solders that could be useful.
This info is from Kester’s web site. Kester is a large manufacturer of solders.
Sn96.5Ag3.5
Sn96.5Ag3.0Cu0.5
Sn99.3Cu0
These solders are apparently workable with a normal soldering iron and are almost all tin, which means the lead oxidation issues are avoided. Obviously tin oxidation will occur, but this would be no different than what we deal with on tinplate track today.
I think the lead free solders Home Depot sells for plumbing may fit the bill.
What I could not find was a comparison of melting temperatures between the old and new solders. My experience with the new lead free solder from HD on some copper plumbing was that I needed more torch heating to get the new stuff to flow cleanly. I also needed more flux.
I picked up some “silver-bearing” solder from HD but refrained from using it because it didn’t say whether or not it was acid- or resin-core and I’ve been told to stay away from the former.