Variable Temp Soldering Iron Newbie

[K8AXW]

Greetings all:  I recently bought a variable temperature soldering station...a Hakko FX-888.  It has an analog temperature scale.  I've checked the tip temperature(s) with a digital thermocouple thermometer and if the the meter is to be believed, the Hakko scale and the actual temperature is about 100° apart. 

Be that as it may, I had to research to find that 60/40 solder melts at 374°F.  I find it necessary to turn the temp control up to approximately 650 on the analog scale to give the results I want.

I'm assuming that the reason for the variable temp control is so that delicate parts can be soldered without overheating them.

If this is the case, how does one know what temperature to set this iron?  Is this variable temp option really used?  I suppose I'm seeking an education for this new toy.

Can some of you younger guys bring me up to speed on this new soldering station?

I'd like to know why I really bought this thing after using a simple Black Beauty iron for 45 years but since I can't answer it myself, I certainly can't expect anyone else to answer this stupid question!

[KB4QAA]

700F is the temperature that NASA specifies in their soldering procedure documents.  In my experience as a military contractor, we used that temp as well.

There are two other factors that must be taken into consideration.

-The size and mass of the components  being soldered
-The size and mass of the soldering pen tip

It's wise to have several tips to select from.

[W9GB]

If this is the case, how does one know what temperature to set this iron?  Is this variable temp option really used?  I suppose I'm seeking an education for this new toy.

Allen --

650°F to 750°F will handle 99% of you hobbyist soldering needs.
For apprentices and novices (at soldering), variable temperature is BAD NEWS.

Soldering relies on a number of variables that needs to be properly balanced.

1. Solder Alloy formation (Sb/Tin-PB/Lead; RoHS/No-Lead).  
http://en.wikipedia.org/wiki/Solder
Tin/lead solders, also called soft solders, are commercially available with tin concentrations
between 5% and 70% by weight.
The greater the tin concentration, the greater the solder’s tensile and shear strengths.

Alloys commonly used for electrical soldering are 60/40 Tin/lead (Sn/Pb)
which melts at 370°F or 188°C and 63/37 Sn/Pb used principally in electrical/electronic work.

The 63/37 is a eutectic alloy, which:
* has the lowest melting point (183°C or 361.4°F) of all the tin/lead alloys; and
* the melting point is truly a point — not a range.

2. Soldering Techniques and Tip Selection
http://en.wikipedia.org/wiki/Soldering

Soldering is a subset of the larger techniques that include Brazing and Welding.

SOLDER IRON TIP SELECTION:
Match the characteristics to the joint to the tip that will perform the work,
The Temperature is a SET ONCE step determined by below and Solder Alloy formulation.

1. PROFILE (Chisel, Screwdriver, Conical, Single Flat, Gull-Wing)
2. SIZE of TIP PROFILE (1/32" to over 1/4"), Hakko uses Metric measures, so convert as needed.
3. OVERALL MASS -  Match the size and profile of iron tip to work.

===
OVERALL RECOOMENDATION for Thru-Hole and Point to Point wiring.

Screwdriver or Chisel Tip ; 1/16" or 3/32" size; Set station to 700 °F ;
Use a 60/40 or 63/37 solder with mild flux (Kester 44) of 0.031" to 0.020" diameter.
The 0.025" diameter for your solder is a good compromise,
if you are doing connector and fine PC board work.

ELECRAFT has soldering recommendations, on their web site, or Kit Builders.

SOLDERING TIPS
By Tom Hammond, N0SS (sk)
http://www.elecraft.com/TechNotes/N0SS_SolderNotes/N0SS_SolderNotesV6.pdf

[K8AXW]

QAA:  Many thanks for your to-the-point reply.  Apparently I figured out what temperature to set my iron by guess...... but good to have authoritative verification!

Thanks again.

Greg:  Many thanks for the raft of information.  You've provided plenty of straight information and have also provided me with several sites on which to do research.  These will be beneficial, I'm sure. 

I especially appreciate your info on the size and shape tips to get for the Hakko.  This was one that was giving a bit of a problem because the 8.5 X 11 sheet of tip points provided by B&D is of poor quality and I'm having a difficult time understanding the info provided.

I think the main benefits I can expect from the new Hakko are very quick warm up, fast tip changes and specialized tips.

My old Black Beauty took a minimum of 3 minutes to warm up and had one tip....large.  The Hakko takes about 15-20 seconds to warm up!

Again, thank you gentlemen for the information I needed.

73

Al - K8AXW

[TANAKASAN]

One other thing to remember if you're new to construction, keep everything clean This means cleaning your PCB, your soldering iron bit and even in some cases the leads of the components.

Tanakasan

[K8AXW]

Bob:  No problem(s) here.  Been doing this for over 50 years.  Even clean the oxidation from the resistor leads!   

I think I just got caught up in the "variable heat solder station" trend.  Sometimes I read something and I get all excited and do stupid stuff like buying one of these things. 

Fortunately, at my age very little excites me anymore!  Even a beautiful blond in a G-string bikini.  OK, so I've also noticed I lie a bit more in my old age........