Tools (7) :
Soldering station
Yihua 8786D

15/06/202323/06/2023.

Soldering station “two-in-one”

My brave old JBC Ironmatic soldering iron from… forty years ago is showing signs of fatigue: set to full power (500 °C), the temperature is struggling to reach 250 °C! As for finding parts… What’s more, the hot air gun I bought a year and a half ago is already out of action (with the promise of an out-of-warranty replacement still a long way off).

So I’m looking for a new combined station: soldering iron and hot air gun.

As is often the case, comparison websites are more like advertisements, especially for Amazon (I’m angry with them), than genuine technical tests. They simply repeat what the sellers write on their websites.

There’s no point looking at the famous brands, JBC, Weller, etc., because they’ll be overpriced. For example, the NASE-2A JBC TOOLS 70 W station, which does not include a soldering iron, costs around €2,000. With incomparable quality and equipment, I’m glad to say…

A little research on the Internet

Here’s the result of a quick web search. It turns out that several stations have similar characteristics, so much so that some seem to have come out of the same workshops…

• Atten ST-8802, the most expensive of my selection, it has some interesting specific features, such as the pre-selection of three different temperatures, for both iron and air.
• Saike. Nothing special to report. In terms of functionality, it is very similar to the following. Rotary knob settings.
• Stamos S-LS-4. Very similar to the others, but with an older design.
• Yihua 8786D. Found on several sites. Push-button settings. It is the one I chose.

So I ordered the Yihua station from AliExpress. I chose the “package 3” with all the accessories, even though some of them are obviously of poor quality, or I already own them. But that doesn’t add much to the price and, as they say, you can always use it…

After 20 days, when the parcel tracking system had been frozen for 13 days, it arrived unannounced and without any external packaging! So the brand and contents were there for all to see…

The box before unpacking.

The station.

The accessories.

List of equipment supplied (“package 3”)

The contents of the package are as follows:

• the station with its air gun;
• a soldering iron;
• a metal iron holder with sponge;
• 3 cylindrical nozzles ø 5, 8, 10 and a square nozzle of 12 mm;
• 1 spare heating element for the gun;
• 1 spare heating element for the iron;
• 5 tips: fine, pointed conical, rounded conical, bevelled cylindrical, flat knife;
• 4 screwdrivers: 1 flat ø 2, 1 Pozidriv ø 1.6, 1 Phillips ø 1.6, 1 Torx ø 1 (approx.);
• 2 crowbar-type pieces and 2 pick-type pieces, all in blue plastic — I presume for removing smartphone screens;
• 1 suction cup with key ring (useful?);
• 1 vacuum pen with 2 nozzles, one straight and one angled, and 4 suction cups ø 3 - 6.5 - 9.5 - 13, none small enough to grip miniature SMDs;
• 1 set of 6 scrapers and a brass brush;
• 1 pair of non-magnetic tweezers;
• 1 desoldering pump;
• 1 coil of 63Sn 37Pb tin-lead solder (theoretically banned in Europe) ø 0.5 mm, length unspecified.

First impressions

the metal (apart from the front panel) casing gives a good impression of robustness. There’s a main switch at the back, which is located to the top, so easy to operate blind. On the front, there’s a separate switch for each function, iron and air.

The 1 m long mains cable cannot be disconnected. The input is protected by a 5 × 20 glass 6.3 A fast fuse. The metal parts of the iron and the gun are properly connected to earth.

The instructions, in English, are fairly precise and correct in terms of language.

Front view.

Rear view.

Soldering iron

The 90 cm long cable is connected by a quality round connector, lockable by a threaded socket, but it holds well without it. It will be easier to disconnect the cable for storage.

Two screws are provided to fix the iron support above the enclosure. I tried it, but this is not practical, too high up. It would have been better on the side.

Hot air gun

This gun is relatively easy to handle: the handle diameter is 32 mm. It is permanently connected to the control box. The cable is 85 cm long and fairly flexible. The gun is stored on the support permanently attached to the left of the control box. Once it has been placed — it’s easy — on its support, the gun is held securely and there is no risk of it tipping over. This is preferable…

Soldering iron test

The temperature displayed rises quickly, very quickly… So quickly that I’m thinking it would need an enormous amount of instantaneous power to achieve it. Odd…

Checking the temperature

With my multimeter fitted with its thermocouple, placed at the end of the tip, I noticed that:

• the temperature rises much more slowly than the display suggests;
• the temperature obtained after stabilisation is much lower than the set point.

Table of temperatures obtained

Display (setpoint)	300	350	400	450	480
Actual temperature	250	270	295	350	300
Delta	−25	−20	−105	−100	−180

Remarks:

• The values obtained should be treated with caution, as I was holding the iron by hand, and its position in relation to the thermocouple could vary. A more accurate measurement would have required a mini insulating cup in which I would have melted a little tin alloy, allowing better heat conduction.
• The temperature obtained at the maximum setting of 480 °C is abnormally low. There may be an overheating safety device at work.

The difference between the set temperature and the obtained temperature, which is sometimes enormous, is probably due to the fact that the iron temperature sensor is located in the heating element, not at the end of the soldering tip. Nevertheless, the manufacturer should take this into account.

Fortunately, it is possible to calibrate the temperature. We’ll see in the hot air gun test. However, if you don’t have a suitable thermometer, the temperatures obtained will be unreliable, to the extent that you won’t be able to melt tin alloy at a supposed 250 °C. In that case, you’ll have to proceed by trial and error.

Hot air gun test

The heating stops automatically when the gun is placed on its support (it’s a bit mysterious, I didn’t see any contact… Perhaps a reed switch?) A good point for safety. You can also press a small button in the centre of the case to put it into standby mode. As with the iron, the temperature rises fairly quickly, but not as much as the display claims. There’s a form of cheating here, let’s not be afraid to say it.

The airflow is adjustable, but not violent, even when set to maximum.

First test

The thermocouple weld is placed in the centre of the nozzle. The air flow is set to maximum. I see a difference of +25 °C on average compared with the display.

Display (setpoint)	100	150	200	250	300	350	400	450
Actual temperature	125	175	223	272	323	376	428	477
Delta	25	25	23	22	23	26	28	27

Here, the display error is much more acceptable than for the iron. Nevertheless, I’m going to carry out a calibration, if only to test this function.

Calibration

First, of course, you need to note down the actual temperature obtained. For example, here, for a setpoint of 300 °C, the value is 323 °C. To switch to calibration mode, press the two arrow-shaped adjustment buttons simultaneously for at least 1 second. The display will show the figures separated by dots. The desired temperature can then be set by pressing the same buttons. To return to the normal display, simply press the two buttons at the same time again.

Calibration done, the result is better, but there are still some abnormal points.

Display (setpoint)	100	150	200	250	300	350	400	450
Actual temperature	104	148	190	249	301	362	423	476
Delta	+4	−2	−10	−1	+1	+12	+23	+26

Different tests (going up or down) give (slightly) different results. It’s not perfect, but it’s very suitable for the applications planned, such as soldering or desoldering SMD components, or shrinking heat-shrink tubing.

Warning: if you reduce the air flow, the temperature will rise above the set point. The regulation is far from perfect.

Is it possible to do multiple calibrations at different temperatures? I put the question to the seller, but I still haven’t received an answer three months later! I don’t want to start a new calibration only to find that the previous one is out of order… Temperature tests take long enough not to add to the work.

Provisional conclusion

I haven’t used this soldering station intensively yet. For the time being, I’m happy with it, once I’ve corrected the setting faults, especially with the soldering iron.