Problems soldering

[Frisbee54]

Hi I've made a start today wiring my new layout but am having problems soldering the droppers for the power feeds.

I've been trying to tin the wires and the rails prior to soldering the two together following a demonstration I came across on You Tube. However unlike the video in which he gets a nice smooth flow of solder all I've been getting is blobs of solder forming on the tip of the iron which then roll off onto the workbench.

Any ideas what I'm doing wrong?

[Flashbang]

Hi
Lack of heat is the most likely cause. The other cause is often an unclean surface!

You need a soldering iron of ideally 25 watt minimum. It MUST have a good condition tip. It does sound as though your irons tip isnt all it should be?
Allow iron to heat up for at least a full 5 minutes.
Clean the area to be soldered, ideally with a fibre pencil and ensure the wire to be solder is also clean.
If possible use a lead content rosen cored solder rather than a lead free. But do ensure you wash your hands after solder work is completed!
Pre tin (wet) the soldering irons tip and apply tip onto the rail where the joint is to be made. Wait a couple of seconds and then feed a little of the rosen cored solder onto the rail, it should flow freely. Remove irons tip.
Pre tin the stripped wire end.
Place the wire onto the pre tinned area of rail and re wet the irons tip. Apply irons tip onto the wire and allow a couple of seconds for the heat to transfer from the iron into the wire and then into the rail. The soldered on the two items should flow into one. Remove iron and do not move the joint for at least 5 to 7 seconds.

[Frisbee54]

Hi Flashbang

Thanks for yet another answer! I've been trying to do exactly as you outline but what's happening is when I apply the solder to the soldering iron bit it just rolls up into a ball and falls off the bit. The Iron is brand new and I've allowed plenty of time for it to heat up. It's a 30W iron and I'm using the solder which came with it which is lead-free so I'll try a lead solder and see if things improve.

[Flashbang]

Hi
The solder rolling off or not flowing over the soldering irons tip is either due to the special coating on the tip being worn away or damaged or the iron just isn't reaching a suitable working temperature.

I recommend the 25 watt Antex XS iron for virtually all model railway electrical soldering work. I have had two for years and years and only purchased replacement tips for them!
Example...Example XS iron (http://www.maplin.co.uk/25w-soldering-iron-type-xs-4063)

I use one of these occasionally, but its rather pricey! Tip cleaner (http://www.maplin.co.uk/tip-tinner-cleaner-3929)

[Frisbee54]

Hi Flashbang
Many thanks for your invaluable advice. The soldering iron I've been using is part of a cheap set so probably isn't up to much. I'll see if I can get hold of an Antex soldering iron and hopefully that will solve the problem. Just one last question, what solder do you recommend?
Thanks once again

[Flashbang]

Hi
For general electrical work I use a 60/40 rosen cored lead content solder.

Like this one for example.....Lead/tin content solder (http://www.rapidonline.com/Tools-Equipment/Solder-30236/?sid=2d5651eb-2c35-4071-aa8f-0c3ce2b167b1)

[ToothFairy]

Hi Flashbang

Thanks for yet another answer! I've been trying to do exactly as you outline but what's happening is when I apply the solder to the soldering iron bit it just rolls up into a ball and falls off the bit. The Iron is brand new and I've allowed plenty of time for it to heat up. It's a 30W iron and I'm using the solder which came with it which is lead-free so I'll try a lead solder and see if things improve.

It's almost certainly the lead-free solder that's causing your problems. Go back to the old-fashioned stuff. And, if the suggestion isn't too late, replace your iron with a temperature-controlled one.

- Michael

[MonstaInk]

juist a quick note on sldering, or tip which ever u prefer

i have had many a bad experiance with soldering till i met a guy that can, and the one thing he always told me is flux.

flux the wire flux the track and more importantly dip your hot solder iron in the flux before adding solder

and do this every time before adding solder to the iron.

hope this helps

oh and a tub of solder flux can be got in the plumers section of b&q or wicks

[Flashbang]

Hi
NEVER use plumbers type flux on any electrical solder joints!
Plumbers flux contains acid which needs to be washed off after use or it will slowly eat through the item soldered and cause a high resistance joint leading to electrical failure. You of course cant wash off a soldered electrical joint.

Only ever use acid fluxes for soldering items such as copper pipes, brass and white metal soldering jobs i.e. building locos or rolling stock as these can be washed under fresh water!

Normal 'Rosen corded solder' has flux built in.
But if if a little more is needed on any ELECTRICAL joint then ONLY EVER USE flux specially designed for that work. Such as Carrs Orange label flux or DCC Concepts Sapphire flux.

[Hamilton]

Part of my job used to include teaching students to solder.
The most common mistake was that they expected the solder on the tip of the iron to be transferred to the joint or whatever like glue. It was often very difficult to convince them that the item BEING soldered had to be hot enough itself to melt the solder. Nor was the importance of flux usually appreciated. The symptoms orignally posted suggest to me that the soldering iron tip was not properly tinned and insufficient heat was being passed to the workpiece and - as has been said - the workpiece is not cleaned sufficiently well.
The next most difficult thing to impress upon them was that a "heat sink" such as a pair of pliers is often a sensible thing to use to prevent conducted heat causing damage elsewhere. Particularly on electrical work.
I must confess that the special tips mentioned are unknown to me and I use copper bits filed clean and to the shape I require and re-tinned whenever necessary. But I must confess that I still have loads of lead solder which I use.
Jim.

[Tricky Dicky]

Having bought many new soldering irons for school use, the problem you describe we found was due to a coating applied over the iron coating more to preserve its appearance whilst it was in stock. Once removed you will find the solder will tin the tip. However, I must caution you to be very careful in cleaning the tip. If you are too abrasive you will cut through the iron coating and although the solder will adhere well to the underlying copper the fluxes will start to produce cavities in the tip especially the more aggressive ones used in lead free solder. To prepare the tip you have a couple of options. Rapid Electronics sell a small ashtray like container which has what appears a brass brillo pad in it. Rubbing the tip in the brass strands as the soldering iron heats up and quickly applying solder to the tip will tin the tip, you may have to repeat it a few times to successfully tin the tip. A quicker method our technicians developed was to use the small brass wire brushes in a Dremel but you really have to give it the lightest of touches.

WARNING Do not use anything more abrasive than brass. Do not use an ordinary brillo pad, glass paper or emery. Do not use plastic scourer either as the plastic will dirty your tip and make things worse. With soldering cleanliness is next to godliness. Rapid and others do sell a tip cleaner and tinning paste into which you just insert the hot tip we did not find it very good it tended to dirty the tip more than it cleaned and tinned.

Once you have tinned the tip the secret is to keep it tinned and clean. I suggest each time you solder a component the first thing is quick wipe on the wet sponge in your soldering iron stand a habit that will preserve your tip for years.

Good luck
Richard

[MonstaInk]

hey flashbang

thanx for that you probbably just saved me a load
as you are most likely aware i would have used flux on all my soldering, think i;ll be getting me some electical flux now as i do believe in it,

and yes a heat sink is a valuable tool as well.

tips are brill they help every body out somewhere

[travellingmatt]

With most solders designed for electrical work you should not need a flux unless you are trying to solder something that is not copper or brass. There should be enough flux in the solder itself.

Tin/Lead solder is now illegal for anything electrical that is to be sold, unless it is for medical, fire, security, or military use, but you can use it yourself as long as you don't sell the stuff you make.

Silver solder (lead-free) is actually better at soldering stuff like rails because it has a stronger flux and works at a higher temperature, but you need a soldering iron that gets hotter, or it just won't work. Also it tends to look grey and if you are used to soldering with lead solder it can look like a 'dry' (faulty) joint, cos the silver solder does not flow so well and tends to ball up and produce foggy, rough solder flows. This is the reason why it is allowed not to use it for anything life-critical, - because a good silver soldered joint can look faulty, it can be hard to detect a faulty joint, so it is relatively unreliable.

As other have said, tinning the iron in the first place can be tricky, especially with lead-free. I use surface mount solder paste to coat the iron before it is ever turned on, and this coats it with flux before it has time to oxidise, but even then, it does sometimes take a good scrub to get the protective coating off. If the iron is plain copper ( really not a good idea with silver solder, and even with lead solder, make sure you use one with copper in it or the iron will hardly last any time at all before you need to replace the bit) then it has to be scrubbed/filed clean before use each time. Iron coated bits MUST NOT be filed or scratched, as once the solder gets through the coating, the chemical reaction will eat away the copper inside really fast, leaving an iron shell that really does not conduct heat well.

Use a bit that is the right size. One that is huge will leave a messy job of a small joint, and one that is too small will not get enough heat into the joint and you will struggle. This is not about the power of the iron, but the tip size. Roughly, I would never solder rail with anything other than about a 3mm tip. Less and you cannot heat the rail enough, more and you will be melting the ties nearby. 25Watts is around the right size. 12 or 17 watt irons are useless, and a 40w iron is only useful if it is controlled by some method.

Make sure the iron is hot and wipe off any old solder on it. It IS acceptable to carry solder to the joint on the iron, contrary to many descriptions, but it has to be no more than a few seconds old. Otherwise the flux has already gone, and it will mess up the joint. When starting out, it is a good idea to use a 'reheat' method, which means coating each object with a good blob of solder, and then add more solder to the iron and use it to reheat both parts together until the two blobs merge into one. The guarantees that you have not just stuck the parts round the edges with a skin of solder, leaving a big dry void between the parts. Later you will be able to hold the two parts together and heat them, then add the stick solder. This of course requires anything up to 4 hands! Twisting two wires and then soldering them has been proven to be mechanically strong but electrically weak, cos it is easy to leave the inside of the twisted area with no solder.

Matt

[alfaz-di-pi]

I was having a problem similar to yours Frisbee, I found it was due to the solder I was using, I could solder with it but it needed too much heat which was damaging other things. I bought some 60/40 off ebay and the problem was solved.

Albert.

[Pete722]

Hi,
I just treated myself to a new Antex CS18, which is a delight to use, and replaces my old Weller W12 with a worn out tip which I can't remove...
However, I was soldering a rail dropper today and tried a different / cheap solder (Blackspur) which comes coiled in a handy small clear tube. It states it is a 60/ 40 lead mix. This solder is horrible to use, seems to need lots of heat to melt, and sets as a dull grey, dry looking joint. I removed what I could with the hot tip, applied flux and re-soldered using my old reel of Archer (Tandy) 60/40 rosin core solder....what an improvement, it flows well and produces a nice bright silvery joint.
Just shows that all 60/40's are not the same !!

Can anyone recommend any other decent quality solders - that would be available from local stores, not via the web due to the weight ?

[southern]

how about maplins store's.

[Flashbang]

Hi
AFAIK Maplin now only sell lead free solder.
Halfords sell lead content cored solder....Link to Halfords (http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_19 6405_langId_-1_categoryId_255210)
Local high street hardware stores (if you can find one!) might also sell small rolls of 60/40 Lead content cored solder?
But larger DIY stores probably wont!

[alfaz-di-pi]

The last time I bought some 60/40 solder it was from Ebay. A company had bought a big load of it and was breaking it down into smaller sizes. I found the price was reasonable when compared to the cost of Halfords.

Albert.