Just use Posi-taps.
gregcI'm curious if a soldering gun couldn't be used for rsistance soldering by using a spring loaded clamp to hold 2 metal contacts opposite the parts being soldered with each metal contact wired to one of the barrels of the gun. A foot switch would make things easy to operate
Resistance soldering uses comparatively low-voltage DC, between 3 and 6 volts in my experience -- plus to the refractory conductive tip that 'does the business'; minus to a grounding clamp or other fairly good grounding connection. I see many who use a conductive plate for 'ground' when working with flat pieces or with a metal vise with conductors at its base.
A Weller gun, on the other hand, is like a 60Hz Tesla coil in reverse: a whole bunch of thin magnet wire (tapped for the trigger switch) for the 120V primary and One Big Honkin' Turn represented by a plated loop... the ends of which are the 'barrels' into which the (heavy wire, which should give you a hint right there!) tip is well secured. I have seen secondary voltage on this reported in the ¼ to ½ volt range... from which you can deduce the available current, also 60Hz AC.
If I understand you correctly, you're proposing to put one side of this interrupted secondary up against the area you want resistance-heated, via point contact, and the other side to the opposite side of the work, also presumably a reasonably 'precise' contact area, and turn on the primary. That's going to be interesting fireworks... it is also the principle of the small welders I see used to fabricate the internals of vacuum or Nixie tubes, or join broken Nichrome elements. Solder seems superfluous when you can fusion-weld far faster than your foot can work that switch...
What might work better is to use a variable-voltage AC source to lower the voltage in the primary, vs. winding a different primary to suit the internal construction of the gun.
Incidentally back in the day I used a modified architectural lead sharpener to keep my tips pointed and clean. I would like to say those things are cheap to buy on eBay now that mechanical pencils have largely replaced leadholders... but that has not been my observation, and a disturbingly large number of those of the same 'certain age' as my architectural study have distorted or broken in ways that make them unfit for purpose...
i'm curious if a soldering gun couldn't be used for rsistance soldering by using a spring loaded clamp to hold 2 metal contacts opposite the parts being soldered with each metal contact wired to one of the barrels of the gun. A foot switch would make things easy to operate
greg - Philadelphia & Reading / Reading
The size you use depends on the length of run. The longer the run, the large the wire size you need to avoid voltage drops over the lenght. There are some tables out there that show the length of run vs. wire size etc.
Rio Grande. The Action Road - Focus 1977-1983
Is it correct to write there is no standard AWG size for buss wires and feeders? I've seen some write 14, 16 or even 12. It seems the size depends on your individual layout, which includes various factors to include consist lengths, types of locos, elevations, etc. Perhaps some recommended practices can help people? This also applies to feeder spacing.
Given the choice between 22 and 20 AWG, I would use the larger. Why? You can make longer runs if needed and not have a voltage drop. While I do try to keep the drops as short as possible, depending on where they are, sometimes I need a longer run to reach the bus wire, and it's good not to be restricted in the length by too much. Besides, 20 AWG is plenty easy to work with and by using solid strand, it's easier to solder on after bending.
As it happens, I'm using 14AWG house wiring for the bus. Having consulted the AWG size chart vs. length of run with little voltage drop, my bus runs from the source are in the 40 to 45' range and depending on the chart some show max run of 40 feet, other charts allow a bit longer, as high as 50'; so I'm at about the max. According to DCC wiki, 16AWG is not recommended for a bus wire for HO.
https://dccwiki.com/Wire_Sizes_and_Spacing
The house wire I bought for the bus is black and white and has a copper ground wire. I stripped out the copper wire.. The 20/2 bell wire I get from Lowes is red and white, so I simply make sure the white goes to white, and the red goes to the black.
I generally make up a bunch of rail joiners with short lengths of feeder wire attached to the underside. I use these during tracklaying to speed up construction, dropping the feeders through pre-drilled holes. I color code the feeders so I know which feeders go to which bus, also color coded, when I get under the layout. I put a big cardboard box beneath where I'm soldering to protect the floor.
It takes an iron man to play with a toy iron horse.
kasskaboose betamax For solder and flux, you need the right kind. The hardware store is oriented toward plumbing, not electronics, so their flux will be acidic and the solder suitable for plumbing. Find a store dealing in electronic supplies or an online retailer and get solder suitable for electronics, such as 60/40 or 63/37 alloys, with rosin flux. Same goes for flux: It must be made for electrical/electronic applications. Tix is not the right flux for electrical work. More info on soldering and DCC: Soldering It depends. The solder I got works fine for MR. I do agree finding an elctronic store is more likely to get what you need. If there's a Harbor Freight around, they migt have what you need. Too bad Radio Shak went kaput.
betamax For solder and flux, you need the right kind. The hardware store is oriented toward plumbing, not electronics, so their flux will be acidic and the solder suitable for plumbing. Find a store dealing in electronic supplies or an online retailer and get solder suitable for electronics, such as 60/40 or 63/37 alloys, with rosin flux. Same goes for flux: It must be made for electrical/electronic applications. Tix is not the right flux for electrical work. More info on soldering and DCC: Soldering
For solder and flux, you need the right kind. The hardware store is oriented toward plumbing, not electronics, so their flux will be acidic and the solder suitable for plumbing.
Find a store dealing in electronic supplies or an online retailer and get solder suitable for electronics, such as 60/40 or 63/37 alloys, with rosin flux. Same goes for flux: It must be made for electrical/electronic applications.
Tix is not the right flux for electrical work.
More info on soldering and DCC: Soldering
It depends. The solder I got works fine for MR. I do agree finding an elctronic store is more likely to get what you need. If there's a Harbor Freight around, they migt have what you need. Too bad Radio Shak went kaput.
Rich
Alton Junction
22 gauge.
"One difference between pessimists and optimists is that while pessimists are more often right, optimists have far more fun."
I bend the bare end of the feeder at 90 degrees and then solder it to the outside of the rail. That way, you can solder the feeder anywhere along the rail without having to solder it to the rail joiner.
If you can, insert the feeders from the top side, use plenty of flux with a 'chip' of solder (or solder paste) rather than holding a piece of solder up to the joint, and as you've chosen use pulse resistance-soldering to the field side of the rail. With resistance soldering the spot heat may be sufficient to bond to the bottom of the rail without melting adjacent ties, which is at least something to consider.
You will benefit from eutectic (fast-freezing) solder formulations. In my opinion, proper 'programming' of the resistance shot would let you use higher-melting solder than you would with a contact iron. Conversely there might be advantages to use a lower-melting electrically-conductive solder to minimize "collateral damage" -- the amount of solder involved being very slight as the joint only requires enough metal to wick in between the feeder and the rail metal. I recommend buying stuff from one of the specialty soldering-supplies providers, not a hardware or big-box store.
As always, be sure to use 'no-clean' flux... but try to clean it afterward anyway.
You can get the flux and solering iron from HD or Lowes. They prob won't have suitable feeder wire, though. I got 20g non-stranded which is perfect.
On my last layout, I used 22 gauge stranded wire for feeders. Worked great. On my current layout, I used 20 gauge solid. Too big. So, I recommend 22 gauge solid.
Hello All,
I am in the process of converting my wiring from radial feeders from a single point to circuit breaker-protected busses.
The new bus wires will be 16ga speaker wire.
I will be using the existing 22ga feeder wires soldered to the field (outside) of the rails.
To attach the feeder wires to the bus wires, I will be using "T" Tap Wire Connectors.
These were suggested in a previous post.
They consist of two (2) parts.
One clamps around the bus wire and cuts through the insulation to make contact with the conductor.
The second part is a crip-on spade connector that is attached to the feeder wire and then slips into the "T" clamped on to the bus wire.
Using these connectors avoids the need to solder under the pike and then having to insulate the solder joints.
If you do decide to solder the feeders to the bus wires I suggest applying some form of "Liquid Tape" to insulate the joints.
"Liquid Tape" can be found at most hardware stores,home improvement centers, and online.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
First time doing this.
20 or 22 guage feeders? Code 100 nickel-silver track. Will use American Beauty 100 watt resistance soldering equipment with tweezers, foot pedal, and power supply per article in Model Railroader June 2021 issue. Will follow instructions, etc in article. Went on website in article for solid wire, gel flux, etc. Any suggestions, etc?