soldering iron temp and solder wire melting point.

[jarthel]

I found this on the kester datasheet:
============
Solder iron tip temperatures are most commonly between 315-371°C (600-700°F) for Sn63Pb37 and
Sn62Pb36Ag02 alloys.
=============

does that mean the melting point is between 315 to 370degrees celcius? I bought a pound of 63/37 and I thought solders with no copper or silver has lower melting point.

thank you.

[jneutron]

lead/tin melts at 183 C. Tin silver at 221C, alloys are close to those numbers.

The soldering tip temp is specified to help the heat get to the parts in a reasonable time, so you don't die of old age trying to melt the solder.

The tradeoffs for soldering are the melt temp, the tip mass, tip temp, the part mass, the part size, how fast the part pulls heat away from the joint.

I prefer the largest tip size practical for the job, with the lowest tip temp practical. That way, the parts don't get excessively hot during the process.

While higher tip temps seem better because the time needed is reduced, it has the potential to get the parts much hotter than you need, killing plastics along the way, and burning flux.

The absolute largest "tip" is a solder pot, of course, with an "infinite" reservoir of heat, and a pot is typically 50 C over melt.

Cheers, John

[djQUAN]

Originally posted by jneutron
I prefer the largest tip size practical for the job, with the lowest tip temp practical. That way, the parts don't get excessively hot during the process.

While higher tip temps seem better because the time needed is reduced, it has the potential to get the parts much hotter than you need, killing plastics along the way, and burning flux.

well, I have been using a non-temp-controlled iron for many years now and don't experience ove heating/burning components. (I now got a cheapie controlled one so I still need a bit of getting used to )

it does have something to do with the time it takes for you to heat the joint. since you can heat it up quicker, you get the do the job faster so given that short if a time, plastics don't have time to melt. I wouldn't recommend it to beginners though.

[jneutron]

Originally posted by djQUAN

well, I have been using a non-temp-controlled iron for many years now and don't experience ove heating/burning components. (I now got a cheapie controlled one so I still need a bit of getting used to )

Experience does play a big role.

Originally posted by djQUAN

it does have something to do with the time it takes for you to heat the joint. since you can heat it up quicker, you get the do the job faster so given that short if a time, plastics don't have time to melt. I wouldn't recommend it to beginners though.

Agreed. That's why I like the lower temp high mass tip, it has the heat capacity to get the joint up quickly, and I don't have to worry so much about the plastics.

What gets me nervous is when someone uses a tiny tip low mass temp controlled iron, and sets the temp very high to speed the process. It allows the system to get considerably hotter than that required for the job. Once the phase change from solid to liquid has occured in the solder, the only thing that slows down the system temp is the heat capacity of the solder and part. If it takes five seconds to get the parts from 30C to 200 C using a 400 C iron, the next five can get it over 300 to 350 C. Epoxies are only good over 200C for seconds at a time, plastics can be even worse.

In my work, it is better to make the process conservative. This reduces the field failures, and here, the field failures can be very, very costly money wise.

Cheers,

[djQUAN]

my temp controlled iron was set by trial and error by using it and seeing the lowest possible setting that I could get away with without resulting to cold solders. works wonderfully. if a job needs something hotter, I crank up the heat a bit and return to the previous setting after that job.

I also agree with the low temp high mass tip. honestly, I haven't had experience with those but I have used for a couple of years a high mass 30W iron (not controlled) and it is able to do big jobs that usually require high wattage irons.

[jarthel]

Originally posted by djQUAN
my temp controlled iron was set by trial and error by using it and seeing the lowest possible setting that I could get away with without resulting to cold solders. works wonderfully. if a job needs something hotter, I crank up the heat a bit and return to the previous setting after that job.

I also agree with the low temp high mass tip. honestly, I haven't had experience with those but I have used for a couple of years a high mass 30W iron (not controlled) and it is able to do big jobs that usually require high wattage irons.

you have the aoyue (hakko clone) station?

my dad is going to quaipo (+ raon) to buy me the desoldering station. I told him it's sold in the shops that sells tools for unblocking/modding cellphones. right?

[djQUAN]

ummm........nope.......
I don't know the brand but it simply looks like a standard 60W iron but with a transparent handle which contains the control circuit. you set the temp by adjusting a trimmer in the handle.

it works pretty well considering the price of Php480 (around US$9.60)

and it takes just seconds for the tip to heat up enough to melt solder. the heater is ceramic and uses standard replacement tips.