Best Solder Temperature?

[tony3d]

I'm going to start building my 555 timer kit from Evil Mad Scientist, and I was wondering what a good temperature would be to set my iron at? I was thinking 600 degrees F.

[Sam__]

What type of solder are you using?

[IanB]

I'm going to start building my 555 timer kit from Evil Mad Scientist, and I was wondering what a good temperature would be to set my iron at? I was thinking 600 degrees F.

You can do this by experiment, since the temperature markings on the iron may not always be accurate.

You want the iron hot enough that the flux bubbles and is activated so that the solder wets the joint efficiently.

You want the iron hot enough that the solder immediately runs freely over and around the joint in a very liquid way without prolonged iron contact.

You don't want the iron so hot that the flux spits and smokes when solder is touched to the iron tip for tinning.

You don't want the iron so hot that the solder on the tip rapidly oxidizes and discolors when on the rest.

[zapta]

Check this series of videos by young Peter Selers. You will be surprised how much you can learn about soldering.

[JNB]

Thanks zapta,  that's an incredible video.  Wish I saw this 45 years ago.  Somehow I survived over the years though.  But,  somehow I learned the hard way.   You kids have it made today....

[mariush]

It's a whole series of videos. Click on the video then look on the side for the next parts in the series, because they contain quite a lot of good useful information.

[IntegratedValve]

The best is whatever Metcal soldering iron sets for you.

[nanofrog]

The best is whatever Metcal soldering iron sets for you.

In the case of a Metcal or similar design, it uses curie point instead of a thermocouple or NTC (negative temperature coefficient thermisostor) based feedback controller. Thus it's the tip that sets the temperature, not the station.

Since everything doesn't always work best at the same temp, manufacturers tend to offer the same profile (chisel, conical, ...) in different temps. Metcal/OKI for example, offers 3x temps (600, 700, and 800F). So there's still temp selection by someone, even though it may not be the actual user. Albeit limited vs. a temp controlled station.

[RogerMc]

You will be surprised how much you can learn about soldering.

Thanks for sharing!

[zapta]

...  You kids have it made today....

Have you tried  tweating all day? It is not as easy as you think  ;-)

[dfmischler]

In the case of a Metcal or similar design, it uses curie point instead of a thermocouple or NTC (negative temperature coefficient thermisostor) based feedback controller. Thus it's the tip that sets the temperature, not the station.

Sounds similar to the old Weller system.  I still have a WTCPN and tips on a shelf someplace (I should just put it on ebay).  You can still get the tips from real vendors, and they are all over ebay.

Since everything doesn't always work best at the same temp, manufacturers tend to offer the same profile (chisel, conical, ...) in different temps. Metcal/OKI for example, offers 3x temps (600, 700, and 800F). So there's still temp selection by someone, even though it may not be the actual user. Albeit limited vs. a temp controlled station.

Yeah, it always bugged me that for a lot of soldering tasks 600F (315C) was a little too low for the WTCPN, and 700F (371C) is a bit too high.  It probably would have worked better if the iron had a lot more heat output and thermal mass, but then the price of tips would probably have been a lot higher.

Edit: I never actually checked to see how big the temperature swing is on the WTCPN...  Might be geeky fun to check...

[zapta]

Sounds similar to the old Weller system.  I still have a WTCPN and tips on a shelf someplace (I should just put it on ebay).  You can still get the tips from real vendors, and they are all over ebay.

IIRC, the old Weller magnetic tips used to control a thermostat switch while the Metcal does not.

[nanofrog]

Sounds similar to the old Weller system.  I still have a WTCPN and tips on a shelf someplace (I should just put it on ebay).  You can still get the tips from real vendors, and they are all over ebay.

It is, but the Weller is a much simpler design (simple switch vs. RF for Metcal).

Yeah, it always bugged me that for a lot of soldering tasks 600F (315C) was a little too low for the WTCPN, and 700F (371C) is a bit too high.  It probably would have worked better if the iron had a lot more heat output and thermal mass, but then the price of tips would probably have been a lot higher.

Aside from cost, there's a balancing act to get heating times to a usable level without causing gross overshoot. A bit more power probably would improve matters IMHO, as 48W is a bit less than what they're producing now for general purpose/PTH oriented irons (65 - 80W currently, though there's even less mass in the tips <i.e. LT series tips used w/ the WSP80 I have>).

Edit: I never actually checked to see how big the temperature swing is on the WTCPN...  Might be geeky fun to check...

It might. 

IIRC, the old Weller magnetic tips used to control a thermostat switch while the Metcal does not.

It's just a magnetic switch connected to the heating element. Below the curie point, the magnetic field keeps the switch closed, activating the heating element. Curie point reached, and it opens. Very simple design, and why they were so reliable. Base is just a transformer, no electronics.

Metcal uses RF induction. It's a lot more complicated, but gives a quicker response than the magnetic switch implementation used in the Wellers.

[ablacon64]

That video is really amazing! In practice, the temperature really depends on the board/part you're soldering (as well as solder alloy and flux). IE, removing an USB conector from a 7 layer laptop board is far more difficult than removing the same conector from a single sided PC board.