Soldering Tempture

[tiny-james]

So I'm looking for advice 

I now have my new switch for my Futaba which needs first to be removed from a small PCB so I can fit it to the transmitter BUT does anyone know what tempture I need to set my soldering iron at (new iron with temp control) I have never used a temp control iron before I have it set at 380 is that to hot ?

[Don Fry]

If it’s 60/40 tin/lead, start at 300°C. Might need a bit more temperature, but you don’t want to bull in China shop it. Other solders exist, different temperatures, but this is what I use for electrical joints.

[tiny-james]

Thank you Don I will try 300 deg first as 280 first and then go up in 10"s

[kc]

Modern lead-free solder seems to need higher temperature -higher than old soldering irons produced.

Old fashioned solder with lead seems to be available still if you need it.  The Component Shop is one supplier

[tiny-james]

Heat, grip and pull is proving harder than I first thought even with a three hand thing 

 

Switch is so so so  close to PCB to get a small screw driver under to help lift it off I think the dremel is coming out to help 

[tiny-james]

I'm using desolder tape

 

[Philip Lewis 3]

If you are taking componennts off a PCB board (if I'm reading you right) with multiple solder joints then you really need a hot air station rather than a soldering iron to melt all the solder points at once.

[Andy Stephenson]

36 minutes ago, Philip Lewis 3 said:

If you are taking componennts off a PCB board (if I'm reading you right) with multiple solder joints then you really need a hot air station rather than a soldering iron to melt all the solder points at once.

...Especially if you are dealing with a double sided PCB (tracks on both sides) There are connections that are made through the thickness of the board called vias and they can be easily pulled out if you get the solder too hot or you apply too much force to the component to be removed.

[tiny-james]

I've given up for now the three pronged switch is not moving any time soon.

I may take the Transmitter to PC world to ask tec department to change the switch over.

soldering is not really my thing and a new soldering hot air gun is what £50.00 

 

New battery (bought) £12.00

New switch (bought) £12.00

New Soldering hot air (not bought) £50.00

RX for Transmitter (bought aliexpress) £25.00

total for repair £99.00

New Futaba T8J £270.00 Second hand about £140.00

 

what would you do?? 

 

[Mike Blandford]

I have mine set to 370, handles lead free solder as well as 60/40. It is very likely the switch was soldered in with lead free solder.

What I do for components like this is to add enough solder (60/40) so it connects all three prongs at the same time. That way, when the solder is molten, the switch may well fall out by itself (all pins desoldered at the same time!). Sometimes, a bit of pressure from the soldering iron will push it out. After the switch is out, then use the desolder tape to clean the board and holes to allow the new switch to be fitted.

Note that with many boards, any ground connection may include a ground plane (a large area of copper connected to the pin). This acts as a heat sink and makes it more difficult to get the connection hot enough, which is why you may need a high temperature.

As with any soldering a high temperature for a short time is better than a lower temperature for a long time.

 

Mike

[Philip Lewis 3]

100% agree with Mike above, hot solder for a short time rather than just have enough heat to melt  the solder, I have mine at 380 and soldering is very quick.

 

You might be able to cut the tabs with some small cutters to remove the switch then de solder and remove the old tabs that are left in the pcb board, you can then (after cleaning it up) solder the individual tabs one at a time.

 

Good luck with PC world! (this isn't what they do).

 

But whatever you do make sure it is 100% good, this is your transmitter and your only connection to the plane!

 

If in doubt find someone who knows what they are doing.

 

Phil

[Piers Bowlan]

I use one of these for desoldering PCBs. Works a treat 👍

[Outrunner]

....or send it to Mike Ridley and get it done properly 

[Caveman]

Lateral thinking - just cut the wires and splice them to the switch wires - no need to disturb the pcb at all.

 

GDB

[Andy Stephenson]

28 minutes ago, Outrunner said:

....or send it to Mike Ridley and get it done properly 

+1 on that.

It's difficult to do a job like that when you have experience and if you haven't then send it to  someone who has.

[Engine Doctor]

I tried swapping our a switch on a FF9 . It was almost impossible to unsolder the old switch as the con5acts went through the board and soldered into tubes that came out with the heat needed! I then used a switch with the pcb from an old unit and spliced the wires. Mark all wies before cutting as Futaba have used a single grey for all the wires.

Or send to Mr Ridley who is recomended by many on this forum. 

[EarlyBird]

9 hours ago, tiny-james said:

soldering is not really my thing

When soldering or de-soldering the transfer of heat from the iron is assisted by adding solder, may seem counter intuitive when de-soldering. Work from the underside so the switch is hanging down. Place the hot iron on one of the soldering points and add solder until the old solder melts it will now be possible to keep adding solder until all three contacts are melted at which point the switch could fall out under gravity but may require a slight pull. Make sure that all three contacts are melted and do not use a lot of force as the PCB tracks are easily damaged.

 

Any problems with the above then bring it to me.

 

Steve

 

 

 

 

[Andy Stephenson]

If I was doing this job, I would take the switch apart whilst still on the PCB using whatever technique required to leave the pins in the board individually separated and remove them one at a time. Trying to remove the switch in one go will almost certainly ruin the PCB.

[Geoff S]

I started my working life repairing radios in Murphy Radio's service dept back in the 1950s.  I found then (and now) that desoldering is much trickier than soldering new components onto a new PCB (although there were few PCBs in 1957 - it was all tag strips!).  The easiest way with devices fitted with multiple pins is to destroy it so that you can remove each pin on its own. On double-sided boards the so-called vias aren't a problem if there's a component pin through them because the pin itself will replace the copper by being soldered to both sides.  However, as I've aged, components have got much smaller and multi-pin surface mounted ICs are extremely difficult to replace without special equipment (though I have done it!)

 

Desoldering often appears to be a three-handed job and the easiest way, if you can, is to hold the job in a small vice (carefully) so you don't end up chasing it round the bench.

[Sparks]

One method is to flood the joint(s) with low-melting point solder (typically 145 dec C)

 

You then have time to remove the component before the joints solidify at a temperature that does not damage the PCB or component.

 

Remove the excess solder with solder wick before fitting the new component with normal solder.  

 

ChipQuik do full kits (expensive) but you can buy the solder by the metre (try here)