Dread of soldering

[Enterprisingwestern]

Depends what you mean by big.

 

Big as in (said in a Jeremy Clarkson style), "more power" is a good thing.

 

I usually use a 50W Weller with 2mm tip for soldering to rail

 

Cheers,

Mick

 

I usually use one of these, although not for soldering rail!

 

 

 

Mike.

[Dick Turpin]

- Lead-free solder is useless.

 

Inevitably you are going to get some people who will spring to it's deference, but I for one hate the damned stuff! How on earth are you going to master a so called black art if you can't even get the correct basic ingredients? The same goes for paint, I do wish I could get old fashioned lead paint for exterior work. We'd better not get distracted off topic onto the merits or otherwise of modern paint!

[The Johnster]

I have now managed to resuscitate my dead loco, despite having soldered a new connection from the rh pickup to a motor feed, cut the capacitor out of circuit to test the motor, and soldered the end of the capacitor lead back on.  Everything is working as smoothly as you'd expect from a Hornby 0-6-0 chassis, and despite my soldering, the body still fits.

 

I have done a job, successfully, involving soldering!

 

Yay me...

[cliff park]

As a (retired) electronics engineer, who must have soldered hundreds of thousands of connections, I agree with Mick. 50 watts is ideal, and if it is thermostatic so much the better. It won't ever get too hot, but will have the power when you need it. You must give the joint, whatever sort, time to heat up, make sure the iron is tinned and apply the cored solder to the joint. NEVER load the iron up with solder.

[Michael Edge]

As a (retired) electronics engineer, who must have soldered hundreds of thousands of connections, I agree with Mick. 50 watts is ideal, and if it is thermostatic so much the better. It won't ever get too hot, but will have the power when you need it. You must give the joint, whatever sort, time to heat up, make sure the iron is tinned and apply the cored solder to the joint. NEVER load the iron up with solder.

 

I don't know how I ever build anything in that case, with the work in one hand and the iron in the other what am I supposed to hold the solder with? The rest of the advice is correct, especially about transfer of heat but liquid solder on the tip of the iron is what makes this possible anyway.

[Oldddudders]

As a (retired) electronics engineer, who must have soldered hundreds of thousands of connections, I agree with Mick. 50 watts is ideal, and if it is thermostatic so much the better. It won't ever get too hot, but will have the power when you need it. You must give the joint, whatever sort, time to heat up, make sure the iron is tinned and apply the cored solder to the joint. NEVER load the iron up with solder.

  

I don't know how I ever build anything in that case, with the work in one hand and the iron in the other what am I supposed to hold the solder with? The rest of the advice is correct, especially about transfer of heat but liquid solder on the tip of the iron is what makes this possible anyway.

Evidently there is more than one way to skin - or even solder - a cat.

[Enterprisingwestern]

  

Evidently there is more than one way to skin - or even solder - a cat.

 

Now, cat soldering, there's a future olympic sport if ever I heard one!

 

Mike.

[Guy Rixon]

The advice about applying the solder directly to the joint is really important when using cored solder without liquid flux. If you carry the solder to the joint on the bit, then the flux from the core is gone, or already reacted, by the time the solder reaches the joint. If you put liquid flux on the joint first, then carrying the solder on the bit does work.

 

Holding the work in one hand is not ideal. I find that if I jig an assembly (such that I could wield solder in one hand and the iron in the other, but I don't), then I get better joints.

 

There exist devices that clamp to a soldering iron and dispense solder from a reel as the iron is applied. I saw one used in a demonstration but have never seen the like on sale.

[kevinlms]

I'm with the OP. I know the ingredients, but the cake doesn't always bake very well. Last night I finally got round to re-soldering an iffy connection. It is on the further side of the rail, and an adjoining backscene means I couldn't really see quite what was going on. Lashings of flux paste on the site and the recalcitrant wire, a drop on the (30 watt, Remploy) iron tip, but it took several goes to get it all to happen, and a couple of (Code 83) sleepers don't now look quite as Peco intended. The track has been in situ for a decade, but never painted.

 

Since I have quite a lot of track, DCC, and have droppers from every rail, I suppose my soldering isn't too bad. But nor is it utterly repeatable, which it would certainly need to be to undertake a brass kit. That remains a step too far.

I noticed that in your description of soldering a wire to track which had been laid down for sometime, you didn't mention scraping the rail. That is an essential part of the job. You CANNOT solder to dirt, even with flux. A scraper, wire brush or even a small screwdriver is required to make a nice shiny surface to get the solder to take.

[2mmMark]

Many years ago, I bought a Heathkit kit for a strobe gun which I took to into work and asked our ever-helpful service engineer how to put it together. He showed me how to solder properly and that was one of the best bits of education I ever had.

 

Soldering is one of those things that is very difficult to learn in abstract.  Being taught hands-on is so much easier.

 

Now, that hot silver glue is my preference whenever it can be used.

 

Mark

[ejstubbs]

Holding the work in one hand is not ideal.

 

If it were possible to agree more than 100% with something then I would with this.  If it's not already fixed in place then the workpiece should be held by a jig or clamp of some kind, leaving your hands free to wield the iron and solder as required.  A very distant second best option is to clamp the iron in position and manipulate the solder and the workpiece.  Trying to kid yourself that you have more than two hands while soldering is just asking for it to go badly IMO.

 

I use a 'helping hands' tool for fiddly soldering, very similar to this one (mine actually came from Lidl).  Even if you don't need the magnifier - I usually use a visor-type magnifier for such jobs anyway - I find the croc clips invaluable.  The depression in the weighted base can take a square of damp sponge which is handy for wiping the iron on.  If the weighted base isn't heavy enough to keep the workpiece stable then you can clamp the thing down (my life was transformed when I discovered the various sizes of ratchet clamps that are available, compared to wrestling with G clamps in the past).

Edited May 24, 2017 by ejstubbs

[PaulCheffus]

I don't know how I ever build anything in that case, with the work in one hand and the iron in the other what am I supposed to hold the solder with? The rest of the advice is correct, especially about transfer of heat but liquid solder on the tip of the iron is what makes this possible anyway.

Hi

 

When soldering PCBs you are relying on the flux in the solder and by transporting the solder on the iron the flux is burnt away. As you are using a separate flux this isn't an issue.

 

Cheers

 

Paul

[Brian]

This is my life long and working life of 45 plus years proven guide to soldering electrical connections. Soldering sheet materials etc is different approach and not covered here.

 

 

The basics of soldering are:- A soldering iron of suitable wattage size and tip for the work being undertaken fitted with a clean bit that’s is first class condition, I prefer to use 60/40 lead content Rosin cored solder and clean connections. …. For everyday soldering a minimum 25 watt iron with a small to medium sized bit is required. Larger bits sizes irons have their place, but are not always needed for most electrical joints. Larger wattage irons are equally fine to use if the irons tip is of a suitable size. A larger wattage iron is often more desirable as the heat transferred into the item being soldered will be much quicker.

 

To make a good quality soldered joint, heat a standard iron for at least four to five minutes. Don’t rush, the irons tip must be up to full temperature. Have to hand a damp soldering iron's tip cleaning sponge pad. If you own a soldering iron stand its likely it came with a sponge. If not, then cut a piece of ordinary non synthetic sponge and use that. Remember to keep the sponge damp. 

Once the iron is hot, wipe the tip onto the sponge to remove all previous oxidisation and old solder residue. Assuming the tip is in a good condition and it must be! Apply a little of the rosin cored solder to the tip. 

 

On electrical joints never use solid stick type solder nor most paste or liquid types of flux, as these all contain a mild acid which over a long period of time causes high resistance problems within the soldered joint. Solid solders and liquid fluxes are normally the reserve of the solid sheet metal soldering jobs – Loco building, plumbing etc.

If you must use flux for electrical joints in addition to what is inbuilt in the rosin cored solder, then ONLY EVER use a special flux designed for electrical soldered joints. It does not contain any harmful acids that would need washing away with water. Examples are:- Carrs Orange label, DCC Concepts Sapphire flux or fluxes sold under the Reflow banner.

 

For jointing two or more wires together….With the irons tip coated in liquid solder (wetted) and having previously dry assembled the joint - It must be cleaned too, use a fibre glass pencil or scrape the surfaces of both components clean, unless its freshly stripped wire where the sheathing keeps the surface of the wire nice and clean. Place the wetted irons tip directly onto the connection. Wait a few seconds for the heat of the tip to transfer into the wires and then apply a little more rosin corded solder onto the heated joint, not onto the irons tip. You should see the solder start to melt and flow into and around the joint. Once sufficient solder has been applied to coat the whole joint remove both the iron and corded solder. NOW DO NOT TOUCH or MOVE the joint. Wait at least 10 seconds after removing the heat to allow the joint to cool and the solder to set. What you should end up with is a solid, clean joint. Sometimes the PVC sheath on the wire/s being soldered will shrink back a little. This is a nuisance at times and is due to a) The wires PVC sheathing having a low temperature range or b) Too much heat applied to the joint for too long a period of time. 

 

Finally, before you go onto solder another joint or you have completely finished and before you disconnect the iron, clean the tip again on the damp sponge. You will get a many years of use from a soldering iron if you keep its tip clean!

 

Soldering wires to the bottom or outside of the rail is the same principle, but here I find pre tinning both the end of the wire and the pre cleaned place on the rail where the wire is to connect to be the best method. Pre clean the rail with the aid of a fibre pencil or other means - file or scraper etc. Tin rail with a little solder, both the place on the rail and the wires end. To Tin, apply a small amount of solder to the clean irons tip, then touch the iron onto the area to be tinned. Heat/Solder will flow from the tip onto the area. This should only take a few seconds, keep the irons tip in place and feed some of the cored solder into the area. Remove iron and wipe the tip on the damp sponge. Once every item has been tinned, place the stripped wire end, which if necessary has been pre bent to a small ‘L’ shape, up to the solder on the rail. Apply a little solder to the irons tip and place the iron on top of the wire and lightly press down towards the rail. The hot solder on the irons tip will cause both the wires solder and the rails solder to melt into one. If necessary apply a little more cored solder onto the wire with the iron still in place should there not be enough on the rail to make a solid connection. Carefully remove the iron and ensure the wire maintains in contact with the rail and doesn’t move, waiting for 5 to 10 seconds to allow the soldered joint to cool. The use of a small screwdriver blade or even tweezers to hold the wire in place until the solder solidifies and prevent your fingers burning is an option I often use. 

 

The use of crocodile clips or any similar sprung clamps fixed onto the rails just either side of the soldering work area are advisable, as these act as ‘mini heat shunts’ and help prevent the rail being overheated away from the soldering area which can, if the heat is allowed to be transmitted along the rail, subsequently causing the plastic sleeper fixings to melt.

 

Don’t forget to wipe the tip on the damp sponge after finishing all the work and before turning off the iron.

 

One thing that I have found for the beginner to soldering, is to obtain a spare scrap piece of track and some pieces of wire and practise, practice and practice until you feel comfortable and at ease with soldering.

Edited May 24, 2017 by Brian

[Crosland]

I don't know how I ever build anything in that case, with the work in one hand and the iron in the other what am I supposed to hold the solder with? The rest of the advice is correct, especially about transfer of heat but liquid solder on the tip of the iron is what makes this possible anyway.

 

All of the advice is correct.

 

It's the difference between electrical work using cored solder and kit building using solder with a separate flux.

[2mmMark]

One of the best soldering aids I've found are the flat aluminium hair clips. These are easily reshaped to clamp parts when being soldered.

 

This is the kind of thing I'm talking about:

Ebay item 171425191786 is one source among many.

 

Little strips of masking tape are also handy. Masking tape seems to cope with the heat reasonably well. Plastic tapes melt quickly.

 

Mark

[cliff park]

And, of course, Mark, the aluminium won't accidentally become soldered to the work, often a problem with crocodile clips.

[newbryford]

Wooden clothes pegs also make useful clamps for soldering.

The "nose" can be cut and shaped to suit the workpiece.

 

Cheers,

Mick

[Crosland]

Wooden clothes pegs also make useful clamps for soldering.

 

Especially the miniature ones intended for hanging pictures and the like.

[Junctionmad]

Again , I wouldn't reccomend anything under 40watts for soldering. If you go to a production line , you will never see 25 watts irons.

 

Wattage has nothing to do with temp

 

My Hakko 40w is up to temp inside 15 secs , wide variety of bits , space for sponge and brass mesh cleaners ( I prefer the brass mesh )

 

My advice for joining wires is tin both ends separately , then bring together and apply iron, rarely is more solder needed

 

Like many , I use leaded solder , which remains widely available. It's only commercial production soldering that must be lead free

 

I find solders with 2% silver to be best

[ruggedpeak]

As another who dreads soldering, the biggest issue I've found is trying to work without melting the power cables to the iron. Cables just get in the way.

 

Having just soldered droppers onto my track for my micro layout, I've found this little gem to be highly effective. Small, easy to use, heats up rapidly and on trickier areas using a small amount of flux have meant the job was easier than previous attempts. Spare tips are a couple of pounds. Just need a can of lighter fluid. Only melted a few sleepers, and that was on points where the gap between sleepers was small.

 

I've got a proper station on order to learn how to do it properly, but working on the baseboard the gas iron was ideal.

[kevinlms]

As another who dreads soldering, the biggest issue I've found is trying to work without melting the power cables to the iron. Cables just get in the way.

 

Having just soldered droppers onto my track for my micro layout, I've found this little gem to be highly effective. Small, easy to use, heats up rapidly and on trickier areas using a small amount of flux have meant the job was easier than previous attempts. Spare tips are a couple of pounds. Just need a can of lighter fluid. Only melted a few sleepers, and that was on points where the gap between sleepers was small.

 

I've got a proper station on order to learn how to do it properly, but working on the baseboard the gas iron was ideal.

You can also get small battery powered soldering irons - powered by 3 AA batteries. They are quite useful for where you occasionally want to solder a few wires on (obviously the batteries don't last too long!).

 

Perhaps they are safer than carrying a container of gas around, in a vehicle. In the event of flat batteries, they can be purchased almost anywhere, certainly much easier than gas canisters.

[Junctionmad]

As another who dreads soldering, the biggest issue I've found is trying to work without melting the power cables to the iron. Cables just get in the way.

 

Having just soldered droppers onto my track for my micro layout, I've found this little gem to be highly effective. Small, easy to use, heats up rapidly and on trickier areas using a small amount of flux have meant the job was easier than previous attempts. Spare tips are a couple of pounds. Just need a can of lighter fluid. Only melted a few sleepers, and that was on points where the gap between sleepers was small.

 

I've got a proper station on order to learn how to do it properly, but working on the baseboard the gas iron was ideal.

 

These things need to be used with care, they are far from ideal , They tend to heat the joint way too hot.

 

They have their uses ( sheet metal etc ) but are no substitute for a proper iron 

[Guy Rixon]

Further up this thread, there's an assertion that one can't solder to dirt. I'd like to qualify that. You shouldn't solder to dirt, but you can, sort of, and that's where some of the beginner's problems come from.

 

In a proper joint - a strong one that conducts electricity - the solder forms a thin layer of alloy with the metal on either side of the joint. If the surfaces are very dirty, then this alloy can't form. However, if  the dirt is crusty enough then the solder can congeal around and between the dirt particles. This gives a weak joint, which does not conduct much. Usually, the joint falls apart immediately. Sometimes, if the universe wishes to mock you, it holds until the part is removed from the jig for cleaning and then gives up. Sometimes it lasts a lot longer.

 

An important edge-case is where the joint is mechanically strong enough, but the dirt layer stops it conducting. This is the classic "dry" joint.

[The Johnster]

Further up this thread, there's an assertion that one can't solder to dirt. I'd like to qualify that. You shouldn't solder to dirt, but you can, sort of, and that's where some of the beginner's problems come from.

 

In a proper joint - a strong one that conducts electricity - the solder forms a thin layer of alloy with the metal on either side of the joint. If the surfaces are very dirty, then this alloy can't form. However, if  the dirt is crusty enough then the solder can congeal around and between the dirt particles. This gives a weak joint, which does not conduct much. Usually, the joint falls apart immediately. Sometimes, if the universe wishes to mock you, it holds until the part is removed from the jig for cleaning and then gives up. Sometimes it lasts a lot longer.

 

An important edge-case is where the joint is mechanically strong enough, but the dirt layer stops it conducting. This is the classic "dry" joint.

 

When, never if, the universe wishes to mock my soldering, it has a habit of allowing me to make joints that will happily take my weight hanging off them, and I am a 'gentleman of a certain carriage', and it will work faultlessly.  Until I take it to an exhibition...