Temperature controlled soldering iron

[hayfield]

I have just got a temperature controlled soldering iron, a bit confused about using it in as much what temperature should I set the irons for differing solders and applications

 

For instance what temp should I set it for 70 degree solder then solder in the range of 135-150

 

Any advice of size of tips and temperatures for differing applications would be welcomed

 

I have a 75 watt iron with a temperature range between 100 & 480 c , plus a range of tips

[RobjUK]

I use an Antex TCS240 for a lot of varied work, both electronics and brass/white metal etc. - and I never change the setting, it's at about 2/3 scale on the pot.. The printing wore off a decade or more ago, I don't know what the actual temperature is.

 

With low melting point solder or white metal, the time the bit is in contact with the solder varies the amount of heat transfer. 

I find that the tip being very hot allows the surface of the parts to get heated enough for solder to flow well, without heating the bulk of the pieces. With a lot of smaller parts I can do them whilst holding them in the correct position. 

 

I do use a lot of flux (6% phosphoric acid, made from 75% rust remover diluted 11:1), which probably also helps regulate the heast as it starts to boil away.

 

For electronics or small to medium brass parts, I use 0.7mm tin-lead  flux cored solder.

 

For larger items or assembling sheet brasswork, I use a miniature blowlamp and solder/flux paste.

[johndon]

For 145 degree solder, I always have the iron temperature set to 400 degrees.

[brossard]

I have a Weller with temp feedback.  I usually set it to 360C when using 188C solder.  For whitemetal, I find 300C to be good (too low a temp and you may end up dithering, increasing the chance of melting the WM).  The trick, I'm sure you know is clean work, lots of flux and in and out quick as you like.  In Tony Wright's DVD on Loco kit building, I recall he said the rule of thumb was roughly to have the iron at twice the solder melting temp.

 

John

[hayfield]

Brossard

 

That's a very useful bit of information,

 

I understand that the tip size also has a bearing

 

With 7 mm kits is it the Temperature or the wattage that matters ? or both ? 

[RobjUK]

Once you get above a certain size of parts, it gets beyond "soldering iron" practicalities, if you also want neatness.

I have a 150W monster, which I tries to use for some chassis work on my first brass kit - it was slow and very! messy.

 

There is just not enough heat transfer through a small contact area between a bit and a large area of brass sheet.

 

The Antex can get large pieces hot enough for small area joints, given time; the big advantage I find with a TC iron is not so much the heat setting as the fact the power ramps up to full as soon as you touch the bit to anything that draw heat from it.

Even that is still messy in some circumstances though, as an area the size of the bit is the smallest that can be used to transfer heat.

 

For small parts or low temperature solder on any size part, it's unbeatable!

 

For brass edge joints or trim parts where I don't want any externally visible solder, I now exclusively use solder paste applied very carefully on the back or along the end of the butt joined part, plus a blowlamp to provide the heat - the joint is flowing within 5 - 10 seconds, with virtually nothing visible away from the joint line.

 

[Andy Hayter]

For low melt, I set my temperature to 200 degrees.  Far too high to be necessary to melt the 70 degree solder but not enough to melt the white metal.  Trial and error I am afraid.

 

Given that you have a little bit of solder, but a massive (in the literal sense) amount of white metal to heat up before the join can be made, I think it makes sense to set the temperature close to but below the melting point of th white metal.

 

For everything else I set the iron to max.  When using for major joints this clearly works, and when using a lower melt solder the power input means that the solder melts before anything else starts to de-solder.

[brossard]

1 hour ago, hayfield said:

Brossard

 

That's a very useful bit of information,

 

I understand that the tip size also has a bearing

 

With 7 mm kits is it the Temperature or the wattage that matters ? or both ? 

 

I think you are right about tip size.  I am using a fairly small bit in my iron.  I have just completed the construction of a D&S 7mm 32' van kit.  I found my Weller iron wouldn't touch it so I mean to get myself a spade bit.  I was able to finish the job using a Weller 80W iron which has a very large bit, too large for precision.  The bit also oxidized very quickly making heat transfer problematic.  So very much a struggle.   It's all about heat availability and transferring it to the work piece.  Wattage means the bit can get back to temp quicker.

 

Time to think about using my mini torch for the next 7mm kit.

 

John

[hayfield]

14 hours ago, Andy Hayter said:

For low melt, I set my temperature to 200 degrees.  Far too high to be necessary to melt the 70 degree solder but not enough to melt the white metal.  Trial and error I am afraid.

 

Given that you have a little bit of solder, but a massive (in the literal sense) amount of white metal to heat up before the join can be made, I think it makes sense to set the temperature close to but below the melting point of th white metal.

 

For everything else I set the iron to max.  When using for major joints this clearly works, and when using a lower melt solder the power input means that the solder melts before anything else starts to de-solder.

 

Andy

 

Thanks I thought whitemetal had a melting point of 135 degrees

[hayfield]

14 hours ago, RobjUK said:

 

The Antex can get large pieces hot enough for small area joints, given time; the big advantage I find with a TC iron is not so much the heat setting as the fact the power ramps up to full as soon as you touch the bit to anything that draw heat from it.

Even that is still messy in some circumstances though, as an area the size of the bit is the smallest that can be used to transfer heat.

 

 

 

 

Rob

 

Thanks, the instruction sheet with the iron is very basic, I think I need to understand how these irons work before I do too much, for instance thought the iron was at full temperature once the sign stopped flashing, not when the tip is on the work. I will phone the company as the chap is very helpful

[RobjUK]

10 minutes ago, hayfield said:

for instance thought the iron was at full temperature once the sign stopped flashing

 

That is exactly right, the tip will be at the set temperature. Think power, not temperature.

 

With a non-TC iron, you start trying to heat a sizeable workpiece and the the tip cools down as there is no more heating power available.

 

With a TC one,  the element power has backed off to a low level once it's at the set heat and idle.

As soon as something tries to to cool it down, the element power ramps up to compensate and try and maintain the set temperature.

 

[hayfield]

Thanks for the explanation. 

[Siberian Snooper]

I have a Weller tc 40 and I set the max to just below full, as I find that at this level it preserves the tip and for soldering whitemetal I turn the iron down and then put the tip on a bit of runner or similar and then gently turn the wick up until it is just starting to melt and turn it down a tad and away I go. No idea what any of the temperatures are.

 

 

[sharris]

19 hours ago, hayfield said:

With 7 mm kits is it the Temperature or the wattage that matters ? or both ? 

 

Remember heat is not the same as temperature. 

 

For anything that requires soldering of hefty chunks of metal, the wattage is the more important thing. Even a small 18W soldering iron will get you up the ~350C to melt electrical solder (fine if you do small amounts of PCB soldering), but put an 18W soldering iron onto a big chunk of metal and the heat will flow away faster than the iron can keep it up.

 

With more watts and a thermostatic controller, your iron will pump more heat into your chunk of metal to keep your joint closer to the set temperature. 

 

BTW - which iron did you go for? I've had an Antex 690SD for years. It's a great iron, but getting a bit old now and I'm wondering what to replace it with should it ever die. 

 

[hayfield]

47 minutes ago, sharris said:

 

Remember heat is not the same as temperature. 

 

For anything that requires soldering of hefty chunks of metal, the wattage is the more important thing. Even a small 18W soldering iron will get you up the ~350C to melt electrical solder (fine if you do small amounts of PCB soldering), but put an 18W soldering iron onto a big chunk of metal and the heat will flow away faster than the iron can keep it up.

 

With more watts and a thermostatic controller, your iron will pump more heat into your chunk of metal to keep your joint closer to the set temperature. 

 

BTW - which iron did you go for? I've had an Antex 690SD for years. It's a great iron, but getting a bit old now and I'm wondering what to replace it with should it ever die. 

 

 

 

Thanks

 

I went for a CSI Premier 75 watt model

[hayfield]

I bought this soldering station after being recommended to it by another member

 

https://www.circuitspecialists.eu/soldering/soldering-stations/csi-premier75w-digital-temperature-controlled-solder-station-with-75w-soldering-iron/

 

Had a chat with the chap on the tec side, who said the temperature needed depends on what's being soldered to what and which solder is being used plus the tip size. Getting to understand it a bit more

[Trainshed Terry]

I have found that a tempture controlled soldering iron of 40watts is not suiteable for "O" gauge brass kits as there is not enough heat in the tip to do a great job of getting the solder to run correctly.

 

My preffrence is a 70 watt for doing "O" gauge brass kits and a "40" watt set up for "oo" gauge kits.

 

Terry.

[hayfield]

Terry

 

I have used a 25 watt iron with a large tip for some work on 0 gauge kits, but as you say what id needed is a bit more power for the larger jobs