Choosing a soldering station

My cheapie pencil iron is really showing its age, and I find it seriously underpowered when working with more massive stuff. I want to replace it with something nice that is pleasant to work with, and lasts a long time.

Here are some products I've been considering:
- Weller WES51, 50Watt, Analog, $110 CAD
- Weller WESD51, 50Watt, Digital, $140 CAD
- Hakko FX-888, 65Watt, Analog, $110 CAD

What is the difference between the analog and digital Weller? Is it just the temperature readout and is that worth the extra $30?

Any feedback would be much appreciated!

I'm liking the Hakko more and more.
- it comes with a chisel tip (better than conical for heat transfer)
- led that turns green when temp is stabilized. don't need to stinkin readout
- compact base station that doesn't look outdated.
and I found a local supplier who would sell it to me for $100. (Interior Electronics)

Picking it up today!

Is is adjustable? I would only buy adjustable, and many of the cheap ones on ebay etc come with digital temp readout which is very handy.

The cheap ones often (usually?) conform to Hakko standard tip sizes so you can get good quality replacement tips and other de-soldering accessories.

I'm sure $100 would get you adjustable temp, 50W or 60W and digital readout.

I gave my new FX-888 a try yesterday...

The station is roughly the size of an old-school pencil sharpener, and feels very sturdy. The stand is anodized aluminum and also feels robust. The hole for the pencil fits snugly and only makes contact with the collar, so no heat is lost. The brass wire tip cleaner is a nice touch. I'm not sure what the rubber scraper is good for yet. The pencil is very well made. It's light and has a comfortable grip that doesn't get hot even at 500°C. The cord is supple so you don't notice it's there, and has silicone rubber boot. The connector seats in smoothly into the station.

It has plenty of power and excellent heat stability. It gets up to operating temperature in under a minute, and holds it very steady even when melting big blogs of solder. Cool-down is slow but who cares.

I used the thermocouple temperature probe of my multimeter (2% accuracy) to test the temperature. The outside of the heater was yellowed so it must have been turned on, and I expected the dial to be calibrated from the factory but it was out by quite a bit. Following the calibration procedure, I set the dial to 350°C, but my probe barely registered 300°C. I used the included tool to turn the pot clockwise until it heated up to 350. The adjustment is incredibly sensitive so it took a few tries, and it took less than a quarter turn. While I had the equipment out, I decided to try a couple more setpoints:
200°C (min) - probe read approx 215°C
480°C (max) - probe read roughly 472 and rose very slowly as if it was struggling.

So far I'm happy with it. I'd be happy to answer any questions if anybody is else considering getting one.

Photos?

Be careful with the temperature calibration, your thermocouple probe will read lower than the actual temp of the heater as it will be cooling in the air (unless you somehow insulate the pair with no heat losses which is difficult!).

Maybe you could use a quality solder with known melt point fromt he solder datasheet and calibrate it based on that?

Congrats too on the new purchase.

I think using solder would be an even less reliable method. As you say, heat is a very dynamic quantity to measure; it's always flowing. To melt solder, you have to overcome losses too, and that's why we set our irons to 350°C when solder melts @ 250°C.

Hakko sells an uninsulated iron thermometer ($220). I suspect that it is designed and calibrated to compensate for losses. Hm, I wonder what tool they used to calibrate the thermometer? And what they used to calibrate that? And ....

Anyway, the thermocouple has a very tiny thermal mass. Close enough for me

timelessbeing said:

Hm, I wonder what tool they used to calibrate the thermometer? And what they used to calibrate that? And ....

Click to expand...

Yeah - I had the same "questions" when I was looking into the tools needed to fully calibrate my Tek 2213 scope (it had been factory calibrated - but I got the service manual, and looked at the procedure - and if I was only able to get the calibration signal generator, I could do it myself - alas, that device would have me re-mortgaging my house to afford it, and of course, that led me to wonder what they calibrate it with - and its cost, ad infintum).

I have a weller and it has served me well for over 20 years, and at the time of purchase it was close to $200 i left the shop wondering if i had bought the right item for the price i had paid.

I have NEVER been sorry for the investment of a good tool.

As for adjustable temperature control my view is, i would not even consider it with a good quality iron as if the iron is always at a constant temp then you quickly learn to adjust your soldering time to suit.

Mine spends hours upon hours running on the bench for years upon years, and the only fault it has ever had was a wire broke in the lead to the iron from excessive use.

The most important thing to consider when buying a good iron is the availability of spare parts and replacement tips as the tips do wear out.

With Weller the range is huge on the tips and i use a 0.6mm tip as it allows for me to do SMD work as well.
To also solder a 6mm cable i can if needed.

The weller dont have all the bells and whistles that some offer, but if you want a reliable work horse than you will be hard pressed to find better. IMO.

I think it around 30 seconds from power on to able to solder with the iron.

Pete.

timelessbeing, I will venture a guess that the calibration of your solder station heat was more accurate from the factory than it is now. My thinking on this runs with that of Mr RB.

Be careful with the temperature calibration, your thermocouple probe will read lower than the actual temp of the heater as it will be cooling in the air (unless you somehow insulate the pair with no heat losses which is difficult!).

Click to expand...

Typically solder station temperature uncertainty is calibrated using a customized standard tip. That tip has a tiny hole drilled into it with a thermocouple junction embedded into the tip. What becomes of great importance is the thermocouple must be a tiny bead welded and the actual thermocouple wire should not exceed AWG 30 in diameter. That is 0.010 inches or about 0.254 mm. This is done for the reasons Mr RB pointed out. We used special fabricated custom tips for this method. Anyway, that is why I figure the factory cal was likely better than the current settings.

It has been a long, long time since my involvement with solder station calibration but as I recall at a temperature set point of 500 F. or 260 C. the acceptable limits of error were +/- 10 degrees F or +/- 6 degrees C.

That method I mentioned tested the uncertainty of the overall system including the tip sensor, usually a thermistor. Another method used was to test the control sans the tip sensor. We used a precision resistance decade box and a test (calibration) fixture.

Most controlled heat solder stations use 4 or 5 wires running from the actual pencil (tool) to the base. Two wires provide power to the element (heater) and two wires connect to the sensor (thermistor). A load is provided to simulate the heater element with a lamp placed across it. A standard resistance is placed across the thermistor lines. This method requires the thermistor tip sensor curve be a known. A set point is set on the station and the decade (precision) resistances are set to simulate a signal from the tip sensor. Using the chart for the thermistor, tip temperatures are simulated. The lamp across the load is observed. A few cardinal points are checked such as 300, 400, 500, 600 and 700 degrees F (or corresponding C).

Finally and I forgot to mention on stations that are designed for use with ESD specifications the fifth wire is a ground so the tip is at ground potential. Additionally for what it may or may not be worth most newer controlled heat stations use a 24 VAC heater element. Note, I said most and not all. Higher end stations also use zero crossover for element power On/Off.

Ron

Ron, thanks for that explanation. I had a hunch it would be something complex like that, using standardized parts and values. This one has 6 pins + the shroud. Output is 26VAC and it is ESD protected.

So I guess mine is out of whack now. I'll phone the store and see if they can recal it for me.

SAborn, Weller USED to be good. My dad still has his soldering gun from way back and you can tell that is was built to last. I recently bought a new model, and it feels like sht in my hand, pardon my french. Many people on the net say the same thing ... Weller quality has gone downhill.

I got this station for a few different reasons...

1- 15W more power @ lower price.
2- Design: The station has a much smaller footprint, and I'm always short on work surface real estate. The holder catches all drips and debris and the brass pad is a nice touch. The whole thing looks sleek and modern, which really impresses the girls. **broken link removed**
3- No useless stuff I don't need like wireless lockout, automatic timer etc. (ie. more stuff that can break)
4. I did a lot of reading, and Hakko reviews from people in the industry are consistently good. The 888's predecessor, the 936, had an excellent reputation.

There are plenty of tips to choose from, and they are widely available, from $5.

I would not overly worry about the cal too much. You can likely get it back where it was using the numbers you posted. Should not be a show stopper problem.

Ron

Yep since Hakko are a quality brand the cal would have been done in factory to be pretty close.

I like the Wellers too, for about 20 years my main workhorse was a fixed temp Weller (actually a curie-point Weller with temperature set by the tips). I still have it but I'm sure it goes through a lot more tips than the newer irons we use now which are cheap brand digital temp adjustable irons (but we use Hakko brand tips).

I think the slow cyclic heat of the Weller damages the metal of the tips, some type of metal fatigue? The point seems to corrode out in a cavity. The digital controlled ones use a PID or similar and the heat is constant when not in use and the tips seem to last a lot longer and don't need to be polished as much.

Of course if you are still using barbaric tip cleaning techniques like a wet sponge that quickly destroys tips too!

calibrating a soldering iron

IIRC, the calibration method by Reloadron refers to the station, the iron and tip is simpler.

Once a station is calibrated its needn't be adjusted further and the scale printed on analog station are matched and permanent. The values are military driven standards, that is 1oF variation for the station, and no more than 10oF variation at the tip under no iron load test conditions, such as touching a conductive trace or terminal.

Irons can be adjusted periodically. Hakko 936 manual recommends checking tip temperature whenever tips are removed such as for replacement or changing tip type; it can also be quality check for performance for worn tips.

All these activities are not mandatory for hobbyists, but if you wish to use as low heat as possible to reduce the risk of damaging small parts such as all SMTs, the procedure is fairly simple and can save you future grief.

Hakko provides a simple method for their irons using the tip thermometer and to summarize, the tip must have liquid solder.

What is measured is the heat of the solder on the tip, not simply the naked tip, if not it can be many degrees lower.

The tip thermometers are mV DVM scaled to the thermocouple, but you can do this yourself with a good DMM, the right size bead K-type thermocouple [ the bead must be small enough that the entire bead or its 2 sense wires are fully immersed in solder] and a good feel.

Because the original test rig is a simple design, copies, counterfeit or used models are easily found on eBay for $10-20 and includes a bag of thermocouples, they work. The key to the tester are the Hakko thermocouples, they retail for ~ $20/bag of 10, $5 for the eBay copies. Counterfeit Hakko FG-100s sell for about $40 on eBay.

timelessbeing said:

I think using solder would be an even less reliable method. As you say, heat is a very dynamic quantity to measure; it's always flowing. To melt solder, you have to overcome losses too, and that's why we set our irons to 350°C when solder melts @ 250°C.

Hakko sells an uninsulated iron thermometer ($220). I suspect that it is designed and calibrated to compensate for losses. Hm, I wonder what tool they used to calibrate the thermometer? And what they used to calibrate that? And ....

Anyway, the thermocouple has a very tiny thermal mass. Close enough for me

Click to expand...

I prefer 25watts soldering iron as it helps componets from being overheat!!

Mr RB said:

Of course if you are still using barbaric tip cleaning techniques like a wet sponge that quickly destroys tips too!

Click to expand...

I would really like to do some reading on this.

I do use the wet sponge method using my cheap $50 Weller but it seems as if the tip is bending a bit over 2 years of use and I don't apply any pressure at all!

The Hakko FX-888 is the cartoonish repackaging of their venerable 936. It's a good station but why, oh why must they make it look like a Fisher-Price or Playskool toy? I'm so glad I have the very serious looking 936.

saturation said:

What is measured is the heat of the solder on the tip, not simply the naked tip, if not it can be many degrees lower.

Click to expand...

This is what I attempted to do using my DMM and temp probe. However the solder was repelled by the thermocouple, even with flux.

KJ6EAD said:

The Hakko FX-888 is the cartoonish repackaging of their venerable 936. It's a good station but why, oh why must they make it look like a Fisher-Price or Playskool toy? I'm so glad I have the very serious looking 936.

Click to expand...

I kind of like the "fun" look. Even if work is boring, tools don't have to looks that way Besides, the 888 is more compact than the 936.

timelessbeing said:

This is what I attempted to do using my DMM and temp probe. However the solder was repelled by the thermocouple, even with flux.
...

Click to expand...

Reloadron on post #9 said you can use a tip with a hole cavity in it, and a thermocouple with very fine wires (so as not to draw the heat away).

Maybe it would be easier to use a non-contact infrared thermometer that would show the average temp of the whole metal mass of the tip.

If I get a chance at work today (Gawd, I hate Mondays) I'll try to either find or make up a tip showing what I was getting at. One picture being worth a thousand words. Just depends on my day and I already know I have a few hot things and meetings. I just don't know if I have any really fine TC wire to build a tiny thermocouple with so things may get ugly. Most of what I have is pretty large TC wire.

Ron

So would the thermocouple seen in the photo I attached in my last post be considered large or small? I don't have any frame of reference.